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| author |   Mike Pagano <mpagano@gentoo.org> | 2024-01-12 17:28:44 -0500 |
|---|---|---|
| committer | Mike Pagano <mpagano@gentoo.org> | 2024-01-12 17:28:44 -0500 |
| commit | 20a1a171771baa15abd085ae7edf2861aa258bd6 (patch) | |
| tree | fc760754f60220c6bf612b17a5628a5231621483 | |
| parent | Create the 6.7 branch with genpatches (diff) | |
| download | linux-patches-20a1a171771baa15abd085ae7edf2861aa258bd6.tar.gz linux-patches-20a1a171771baa15abd085ae7edf2861aa258bd6.tar.bz2 linux-patches-20a1a171771baa15abd085ae7edf2861aa258bd6.zip | |
Add BMQ(BitMap Queue) Scheduler, use=experimental
Signed-off-by: Mike Pagano <mpagano@gentoo.org>
| -rw-r--r-- | 0000_README | 4 | ||||
| -rw-r--r-- | 5020_BMQ-and-PDS-io-scheduler-v6.7-r0.patch | 11240 |
2 files changed, 11244 insertions, 0 deletions
diff --git a/0000_README b/0000_README index c4cff3f2..e23280d4 100644 --- a/0000_README +++ b/0000_README @@ -86,3 +86,7 @@ Desc: Add Gentoo Linux support config settings and defaults. Patch: 5010_enable-cpu-optimizations-universal.patch From: https://github.com/graysky2/kernel_compiler_patch Desc: Kernel >= 5.15 patch enables gcc = v11.1+ optimizations for additional CPUs. + +Patch: 5020_BMQ-and-PDS-io-scheduler-v6.7-r0.patch +From: https://gitlab.com/alfredchen/projectc +Desc: BMQ(BitMap Queue) Scheduler. A new CPU scheduler developed from PDS(incld). Inspired by the scheduler in zircon. diff --git a/5020_BMQ-and-PDS-io-scheduler-v6.7-r0.patch b/5020_BMQ-and-PDS-io-scheduler-v6.7-r0.patch new file mode 100644 index 00000000..d0ff29ff --- /dev/null +++ b/5020_BMQ-and-PDS-io-scheduler-v6.7-r0.patch @@ -0,0 +1,11240 @@ +diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt +index 65731b060e3f..56f8c9453e24 100644 +--- a/Documentation/admin-guide/kernel-parameters.txt ++++ b/Documentation/admin-guide/kernel-parameters.txt +@@ -5714,6 +5714,12 @@ + sa1100ir [NET] + See drivers/net/irda/sa1100_ir.c. + ++ sched_timeslice= ++ [KNL] Time slice in ms for Project C BMQ/PDS scheduler. ++ Format: integer 2, 4 ++ Default: 4 ++ See Documentation/scheduler/sched-BMQ.txt ++ + sched_verbose [KNL] Enables verbose scheduler debug messages. + + schedstats= [KNL,X86] Enable or disable scheduled statistics. +diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst +index 6584a1f9bfe3..e332d9eff0d4 100644 +--- a/Documentation/admin-guide/sysctl/kernel.rst ++++ b/Documentation/admin-guide/sysctl/kernel.rst +@@ -1646,3 +1646,13 @@ is 10 seconds. + + The softlockup threshold is (``2 * watchdog_thresh``). Setting this + tunable to zero will disable lockup detection altogether. ++ ++yield_type: ++=========== ++ ++BMQ/PDS CPU scheduler only. This determines what type of yield calls ++to sched_yield will perform. ++ ++ 0 - No yield. ++ 1 - Deboost and requeue task. (default) ++ 2 - Set run queue skip task. +diff --git a/Documentation/scheduler/sched-BMQ.txt b/Documentation/scheduler/sched-BMQ.txt +new file mode 100644 +index 000000000000..05c84eec0f31 +--- /dev/null ++++ b/Documentation/scheduler/sched-BMQ.txt +@@ -0,0 +1,110 @@ ++ BitMap queue CPU Scheduler ++ -------------------------- ++ ++CONTENT ++======== ++ ++ Background ++ Design ++ Overview ++ Task policy ++ Priority management ++ BitMap Queue ++ CPU Assignment and Migration ++ ++ ++Background ++========== ++ ++BitMap Queue CPU scheduler, referred to as BMQ from here on, is an evolution ++of previous Priority and Deadline based Skiplist multiple queue scheduler(PDS), ++and inspired by Zircon scheduler. The goal of it is to keep the scheduler code ++simple, while efficiency and scalable for interactive tasks, such as desktop, ++movie playback and gaming etc. ++ ++Design ++====== ++ ++Overview ++-------- ++ ++BMQ use per CPU run queue design, each CPU(logical) has it's own run queue, ++each CPU is responsible for scheduling the tasks that are putting into it's ++run queue. ++ ++The run queue is a set of priority queues. Note that these queues are fifo ++queue for non-rt tasks or priority queue for rt tasks in data structure. See ++BitMap Queue below for details. BMQ is optimized for non-rt tasks in the fact ++that most applications are non-rt tasks. No matter the queue is fifo or ++priority, In each queue is an ordered list of runnable tasks awaiting execution ++and the data structures are the same. When it is time for a new task to run, ++the scheduler simply looks the lowest numbered queueue that contains a task, ++and runs the first task from the head of that queue. And per CPU idle task is ++also in the run queue, so the scheduler can always find a task to run on from ++its run queue. ++ ++Each task will assigned the same timeslice(default 4ms) when it is picked to ++start running. Task will be reinserted at the end of the appropriate priority ++queue when it uses its whole timeslice. When the scheduler selects a new task ++from the priority queue it sets the CPU's preemption timer for the remainder of ++the previous timeslice. When that timer fires the scheduler will stop execution ++on that task, select another task and start over again. ++ ++If a task blocks waiting for a shared resource then it's taken out of its ++priority queue and is placed in a wait queue for the shared resource. When it ++is unblocked it will be reinserted in the appropriate priority queue of an ++eligible CPU. ++ ++Task policy ++----------- ++ ++BMQ supports DEADLINE, FIFO, RR, NORMAL, BATCH and IDLE task policy like the ++mainline CFS scheduler. But BMQ is heavy optimized for non-rt task, that's ++NORMAL/BATCH/IDLE policy tasks. Below is the implementation detail of each ++policy. ++ ++DEADLINE ++ It is squashed as priority 0 FIFO task. ++ ++FIFO/RR ++ All RT tasks share one single priority queue in BMQ run queue designed. The ++complexity of insert operation is O(n). BMQ is not designed for system runs ++with major rt policy tasks. ++ ++NORMAL/BATCH/IDLE ++ BATCH and IDLE tasks are treated as the same policy. They compete CPU with ++NORMAL policy tasks, but they just don't boost. To control the priority of ++NORMAL/BATCH/IDLE tasks, simply use nice level. ++ ++ISO ++ ISO policy is not supported in BMQ. Please use nice level -20 NORMAL policy ++task instead. ++ ++Priority management ++------------------- ++ ++RT tasks have priority from 0-99. For non-rt tasks, there are three different ++factors used to determine the effective priority of a task. The effective ++priority being what is used to determine which queue it will be in. ++ ++The first factor is simply the task’s static priority. Which is assigned from ++task's nice level, within [-20, 19] in userland's point of view and [0, 39] ++internally. ++ ++The second factor is the priority boost. This is a value bounded between ++[-MAX_PRIORITY_ADJ, MAX_PRIORITY_ADJ] used to offset the base priority, it is ++modified by the following cases: ++ ++*When a thread has used up its entire timeslice, always deboost its boost by ++increasing by one. ++*When a thread gives up cpu control(voluntary or non-voluntary) to reschedule, ++and its switch-in time(time after last switch and run) below the thredhold ++based on its priority boost, will boost its boost by decreasing by one buti is ++capped at 0 (won’t go negative). ++ ++The intent in this system is to ensure that interactive threads are serviced ++quickly. These are usually the threads that interact directly with the user ++and cause user-perceivable latency. These threads usually do little work and ++spend most of their time blocked awaiting another user event. So they get the ++priority boost from unblocking while background threads that do most of the ++processing receive the priority penalty for using their entire timeslice. +diff --git a/fs/proc/base.c b/fs/proc/base.c +index dd31e3b6bf77..12d1248cb4df 100644 +--- a/fs/proc/base.c ++++ b/fs/proc/base.c +@@ -480,7 +480,7 @@ static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, + seq_puts(m, "0 0 0\n"); + else + seq_printf(m, "%llu %llu %lu\n", +- (unsigned long long)task->se.sum_exec_runtime, ++ (unsigned long long)tsk_seruntime(task), + (unsigned long long)task->sched_info.run_delay, + task->sched_info.pcount); + +diff --git a/include/asm-generic/resource.h b/include/asm-generic/resource.h +index 8874f681b056..59eb72bf7d5f 100644 +--- a/include/asm-generic/resource.h ++++ b/include/asm-generic/resource.h +@@ -23,7 +23,7 @@ + [RLIMIT_LOCKS] = { RLIM_INFINITY, RLIM_INFINITY }, \ + [RLIMIT_SIGPENDING] = { 0, 0 }, \ + [RLIMIT_MSGQUEUE] = { MQ_BYTES_MAX, MQ_BYTES_MAX }, \ +- [RLIMIT_NICE] = { 0, 0 }, \ ++ [RLIMIT_NICE] = { 30, 30 }, \ + [RLIMIT_RTPRIO] = { 0, 0 }, \ + [RLIMIT_RTTIME] = { RLIM_INFINITY, RLIM_INFINITY }, \ + } +diff --git a/include/linux/sched.h b/include/linux/sched.h +index 292c31697248..f5b026795dc6 100644 +--- a/include/linux/sched.h ++++ b/include/linux/sched.h +@@ -769,8 +769,14 @@ struct task_struct { + unsigned int ptrace; + + #ifdef CONFIG_SMP +- int on_cpu; + struct __call_single_node wake_entry; ++#endif ++#if defined(CONFIG_SMP) || defined(CONFIG_SCHED_ALT) ++ int on_cpu; ++#endif ++ ++#ifdef CONFIG_SMP ++#ifndef CONFIG_SCHED_ALT + unsigned int wakee_flips; + unsigned long wakee_flip_decay_ts; + struct task_struct *last_wakee; +@@ -784,6 +790,7 @@ struct task_struct { + */ + int recent_used_cpu; + int wake_cpu; ++#endif /* !CONFIG_SCHED_ALT */ + #endif + int on_rq; + +@@ -792,6 +799,20 @@ struct task_struct { + int normal_prio; + unsigned int rt_priority; + ++#ifdef CONFIG_SCHED_ALT ++ u64 last_ran; ++ s64 time_slice; ++ int sq_idx; ++ struct list_head sq_node; ++#ifdef CONFIG_SCHED_BMQ ++ int boost_prio; ++#endif /* CONFIG_SCHED_BMQ */ ++#ifdef CONFIG_SCHED_PDS ++ u64 deadline; ++#endif /* CONFIG_SCHED_PDS */ ++ /* sched_clock time spent running */ ++ u64 sched_time; ++#else /* !CONFIG_SCHED_ALT */ + struct sched_entity se; + struct sched_rt_entity rt; + struct sched_dl_entity dl; +@@ -802,6 +823,7 @@ struct task_struct { + unsigned long core_cookie; + unsigned int core_occupation; + #endif ++#endif /* !CONFIG_SCHED_ALT */ + + #ifdef CONFIG_CGROUP_SCHED + struct task_group *sched_task_group; +@@ -1561,6 +1583,15 @@ struct task_struct { + */ + }; + ++#ifdef CONFIG_SCHED_ALT ++#define tsk_seruntime(t) ((t)->sched_time) ++/* replace the uncertian rt_timeout with 0UL */ ++#define tsk_rttimeout(t) (0UL) ++#else /* CFS */ ++#define tsk_seruntime(t) ((t)->se.sum_exec_runtime) ++#define tsk_rttimeout(t) ((t)->rt.timeout) ++#endif /* !CONFIG_SCHED_ALT */ ++ + static inline struct pid *task_pid(struct task_struct *task) + { + return task->thread_pid; +diff --git a/include/linux/sched/deadline.h b/include/linux/sched/deadline.h +index df3aca89d4f5..1df1f7635188 100644 +--- a/include/linux/sched/deadline.h ++++ b/include/linux/sched/deadline.h +@@ -2,6 +2,25 @@ + #ifndef _LINUX_SCHED_DEADLINE_H + #define _LINUX_SCHED_DEADLINE_H + ++#ifdef CONFIG_SCHED_ALT ++ ++static inline int dl_task(struct task_struct *p) ++{ ++ return 0; ++} ++ ++#ifdef CONFIG_SCHED_BMQ ++#define __tsk_deadline(p) (0UL) ++#endif ++ ++#ifdef CONFIG_SCHED_PDS ++#define __tsk_deadline(p) ((((u64) ((p)->prio))<<56) | (p)->deadline) ++#endif ++ ++#else ++ ++#define __tsk_deadline(p) ((p)->dl.deadline) ++ + /* + * SCHED_DEADLINE tasks has negative priorities, reflecting + * the fact that any of them has higher prio than RT and +@@ -23,6 +42,7 @@ static inline int dl_task(struct task_struct *p) + { + return dl_prio(p->prio); + } ++#endif /* CONFIG_SCHED_ALT */ + + static inline bool dl_time_before(u64 a, u64 b) + { +diff --git a/include/linux/sched/prio.h b/include/linux/sched/prio.h +index ab83d85e1183..a9a1dfa99140 100644 +--- a/include/linux/sched/prio.h ++++ b/include/linux/sched/prio.h +@@ -18,6 +18,32 @@ + #define MAX_PRIO (MAX_RT_PRIO + NICE_WIDTH) + #define DEFAULT_PRIO (MAX_RT_PRIO + NICE_WIDTH / 2) + ++#ifdef CONFIG_SCHED_ALT ++ ++/* Undefine MAX_PRIO and DEFAULT_PRIO */ ++#undef MAX_PRIO ++#undef DEFAULT_PRIO ++ ++/* +/- priority levels from the base priority */ ++#ifdef CONFIG_SCHED_BMQ ++#define MAX_PRIORITY_ADJ (12) ++ ++#define MIN_NORMAL_PRIO (MAX_RT_PRIO) ++#define MAX_PRIO (MIN_NORMAL_PRIO + NICE_WIDTH) ++#define DEFAULT_PRIO (MIN_NORMAL_PRIO + NICE_WIDTH / 2) ++#endif ++ ++#ifdef CONFIG_SCHED_PDS ++#define MAX_PRIORITY_ADJ (0) ++ ++#define MIN_NORMAL_PRIO (128) ++#define NORMAL_PRIO_NUM (64) ++#define MAX_PRIO (MIN_NORMAL_PRIO + NORMAL_PRIO_NUM) ++#define DEFAULT_PRIO (MAX_PRIO - NICE_WIDTH / 2) ++#endif ++ ++#endif /* CONFIG_SCHED_ALT */ ++ + /* + * Convert user-nice values [ -20 ... 0 ... 19 ] + * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], +diff --git a/include/linux/sched/rt.h b/include/linux/sched/rt.h +index b2b9e6eb9683..09bd4d8758b2 100644 +--- a/include/linux/sched/rt.h ++++ b/include/linux/sched/rt.h +@@ -24,8 +24,10 @@ static inline bool task_is_realtime(struct task_struct *tsk) + + if (policy == SCHED_FIFO || policy == SCHED_RR) + return true; ++#ifndef CONFIG_SCHED_ALT + if (policy == SCHED_DEADLINE) + return true; ++#endif + return false; + } + +diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h +index de545ba85218..941bb18ff72c 100644 +--- a/include/linux/sched/topology.h ++++ b/include/linux/sched/topology.h +@@ -238,7 +238,8 @@ static inline bool cpus_share_resources(int this_cpu, int that_cpu) + + #endif /* !CONFIG_SMP */ + +-#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) ++#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) && \ ++ !defined(CONFIG_SCHED_ALT) + extern void rebuild_sched_domains_energy(void); + #else + static inline void rebuild_sched_domains_energy(void) +diff --git a/init/Kconfig b/init/Kconfig +index 9ffb103fc927..8f0b7eeff77e 100644 +--- a/init/Kconfig ++++ b/init/Kconfig +@@ -629,6 +629,7 @@ config TASK_IO_ACCOUNTING + + config PSI + bool "Pressure stall information tracking" ++ depends on !SCHED_ALT + select KERNFS + help + Collect metrics that indicate how overcommitted the CPU, memory, +@@ -794,6 +795,7 @@ menu "Scheduler features" + config UCLAMP_TASK + bool "Enable utilization clamping for RT/FAIR tasks" + depends on CPU_FREQ_GOV_SCHEDUTIL ++ depends on !SCHED_ALT + help + This feature enables the scheduler to track the clamped utilization + of each CPU based on RUNNABLE tasks scheduled on that CPU. +@@ -840,6 +842,35 @@ config UCLAMP_BUCKETS_COUNT + + If in doubt, use the default value. + ++menuconfig SCHED_ALT ++ bool "Alternative CPU Schedulers" ++ default y ++ help ++ This feature enable alternative CPU scheduler" ++ ++if SCHED_ALT ++ ++choice ++ prompt "Alternative CPU Scheduler" ++ default SCHED_BMQ ++ ++config SCHED_BMQ ++ bool "BMQ CPU scheduler" ++ help ++ The BitMap Queue CPU scheduler for excellent interactivity and ++ responsiveness on the desktop and solid scalability on normal ++ hardware and commodity servers. ++ ++config SCHED_PDS ++ bool "PDS CPU scheduler" ++ help ++ The Priority and Deadline based Skip list multiple queue CPU ++ Scheduler. ++ ++endchoice ++ ++endif ++ + endmenu + + # +@@ -893,6 +924,7 @@ config NUMA_BALANCING + depends on ARCH_SUPPORTS_NUMA_BALANCING + depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY + depends on SMP && NUMA && MIGRATION && !PREEMPT_RT ++ depends on !SCHED_ALT + help + This option adds support for automatic NUMA aware memory/task placement. + The mechanism is quite primitive and is based on migrating memory when +@@ -990,6 +1022,7 @@ config FAIR_GROUP_SCHED + depends on CGROUP_SCHED + default CGROUP_SCHED + ++if !SCHED_ALT + config CFS_BANDWIDTH + bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED" + depends on FAIR_GROUP_SCHED +@@ -1012,6 +1045,7 @@ config RT_GROUP_SCHED + realtime bandwidth for them. + See Documentation/scheduler/sched-rt-group.rst for more information. + ++endif #!SCHED_ALT + endif #CGROUP_SCHED + + config SCHED_MM_CID +@@ -1260,6 +1294,7 @@ config CHECKPOINT_RESTORE + + config SCHED_AUTOGROUP + bool "Automatic process group scheduling" ++ depends on !SCHED_ALT + select CGROUPS + select CGROUP_SCHED + select FAIR_GROUP_SCHED +diff --git a/init/init_task.c b/init/init_task.c +index 5727d42149c3..e2e2622d50d5 100644 +--- a/init/init_task.c ++++ b/init/init_task.c +@@ -75,9 +75,15 @@ struct task_struct init_task + .stack = init_stack, + .usage = REFCOUNT_INIT(2), + .flags = PF_KTHREAD, ++#ifdef CONFIG_SCHED_ALT ++ .prio = DEFAULT_PRIO + MAX_PRIORITY_ADJ, ++ .static_prio = DEFAULT_PRIO, ++ .normal_prio = DEFAULT_PRIO + MAX_PRIORITY_ADJ, ++#else + .prio = MAX_PRIO - 20, + .static_prio = MAX_PRIO - 20, + .normal_prio = MAX_PRIO - 20, ++#endif + .policy = SCHED_NORMAL, + .cpus_ptr = &init_task.cpus_mask, + .user_cpus_ptr = NULL, +@@ -89,6 +95,17 @@ struct task_struct init_task + .restart_block = { + .fn = do_no_restart_syscall, + }, ++#ifdef CONFIG_SCHED_ALT ++ .sq_node = LIST_HEAD_INIT(init_task.sq_node), ++#ifdef CONFIG_SCHED_BMQ ++ .boost_prio = 0, ++ .sq_idx = 15, ++#endif ++#ifdef CONFIG_SCHED_PDS ++ .deadline = 0, ++#endif ++ .time_slice = HZ, ++#else + .se = { + .group_node = LIST_HEAD_INIT(init_task.se.group_node), + }, +@@ -96,6 +113,7 @@ struct task_struct init_task + .run_list = LIST_HEAD_INIT(init_task.rt.run_list), + .time_slice = RR_TIMESLICE, + }, ++#endif + .tasks = LIST_HEAD_INIT(init_task.tasks), + #ifdef CONFIG_SMP + .pushable_tasks = PLIST_NODE_INIT(init_task.pushable_tasks, MAX_PRIO), +diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt +index c2f1fd95a821..41654679b1b2 100644 +--- a/kernel/Kconfig.preempt ++++ b/kernel/Kconfig.preempt +@@ -117,7 +117,7 @@ config PREEMPT_DYNAMIC + + config SCHED_CORE + bool "Core Scheduling for SMT" +- depends on SCHED_SMT ++ depends on SCHED_SMT && !SCHED_ALT + help + This option permits Core Scheduling, a means of coordinated task + selection across SMT siblings. When enabled -- see +diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c +index 615daaf87f1f..16fb54ec732c 100644 +--- a/kernel/cgroup/cpuset.c ++++ b/kernel/cgroup/cpuset.c +@@ -848,7 +848,7 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial) + return ret; + } + +-#ifdef CONFIG_SMP ++#if defined(CONFIG_SMP) && !defined(CONFIG_SCHED_ALT) + /* + * Helper routine for generate_sched_domains(). + * Do cpusets a, b have overlapping effective cpus_allowed masks? +@@ -1247,7 +1247,7 @@ static void rebuild_sched_domains_locked(void) + /* Have scheduler rebuild the domains */ + partition_and_rebuild_sched_domains(ndoms, doms, attr); + } +-#else /* !CONFIG_SMP */ ++#else /* !CONFIG_SMP || CONFIG_SCHED_ALT */ + static void rebuild_sched_domains_locked(void) + { + } +@@ -3206,12 +3206,15 @@ static int cpuset_can_attach(struct cgroup_taskset *tset) + goto out_unlock; + } + ++#ifndef CONFIG_SCHED_ALT + if (dl_task(task)) { + cs->nr_migrate_dl_tasks++; + cs->sum_migrate_dl_bw += task->dl.dl_bw; + } ++#endif + } + ++#ifndef CONFIG_SCHED_ALT + if (!cs->nr_migrate_dl_tasks) + goto out_success; + +@@ -3232,6 +3235,7 @@ static int cpuset_can_attach(struct cgroup_taskset *tset) + } + + out_success: ++#endif + /* + * Mark attach is in progress. This makes validate_change() fail + * changes which zero cpus/mems_allowed. +@@ -3255,12 +3259,14 @@ static void cpuset_cancel_attach(struct cgroup_taskset *tset) + if (!cs->attach_in_progress) + wake_up(&cpuset_attach_wq); + ++#ifndef CONFIG_SCHED_ALT + if (cs->nr_migrate_dl_tasks) { + int cpu = cpumask_any(cs->effective_cpus); + + dl_bw_free(cpu, cs->sum_migrate_dl_bw); + reset_migrate_dl_data(cs); + } ++#endif + + mutex_unlock(&cpuset_mutex); + } +diff --git a/kernel/delayacct.c b/kernel/delayacct.c +index 6f0c358e73d8..8111481ce8b1 100644 +--- a/kernel/delayacct.c ++++ b/kernel/delayacct.c +@@ -150,7 +150,7 @@ int delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) + */ + t1 = tsk->sched_info.pcount; + t2 = tsk->sched_info.run_delay; +- t3 = tsk->se.sum_exec_runtime; ++ t3 = tsk_seruntime(tsk); + + d->cpu_count += t1; + +diff --git a/kernel/exit.c b/kernel/exit.c +index aedc0832c9f4..ff8bf6cddc34 100644 +--- a/kernel/exit.c ++++ b/kernel/exit.c +@@ -174,7 +174,7 @@ static void __exit_signal(struct task_struct *tsk) + sig->curr_target = next_thread(tsk); + } + +- add_device_randomness((const void*) &tsk->se.sum_exec_runtime, ++ add_device_randomness((const void*) &tsk_seruntime(tsk), + sizeof(unsigned long long)); + + /* +@@ -195,7 +195,7 @@ static void __exit_signal(struct task_struct *tsk) + sig->inblock += task_io_get_inblock(tsk); + sig->oublock += task_io_get_oublock(tsk); + task_io_accounting_add(&sig->ioac, &tsk->ioac); +- sig->sum_sched_runtime += tsk->se.sum_exec_runtime; ++ sig->sum_sched_runtime += tsk_seruntime(tsk); + sig->nr_threads--; + __unhash_process(tsk, group_dead); + write_sequnlock(&sig->stats_lock); +diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c +index 4a10e8c16fd2..cfbbdd64b851 100644 +--- a/kernel/locking/rtmutex.c ++++ b/kernel/locking/rtmutex.c +@@ -362,7 +362,7 @@ waiter_update_prio(struct rt_mutex_waiter *waiter, struct task_struct *task) + lockdep_assert(RB_EMPTY_NODE(&waiter->tree.entry)); + + waiter->tree.prio = __waiter_prio(task); +- waiter->tree.deadline = task->dl.deadline; ++ waiter->tree.deadline = __tsk_deadline(task); + } + + /* +@@ -383,16 +383,20 @@ waiter_clone_prio(struct rt_mutex_waiter *waiter, struct task_struct *task) + * Only use with rt_waiter_node_{less,equal}() + */ + #define task_to_waiter_node(p) \ +- &(struct rt_waiter_node){ .prio = __waiter_prio(p), .deadline = (p)->dl.deadline } ++ &(struct rt_waiter_node){ .prio = __waiter_prio(p), .deadline = __tsk_deadline(p) } + #define task_to_waiter(p) \ + &(struct rt_mutex_waiter){ .tree = *task_to_waiter_node(p) } + + static __always_inline int rt_waiter_node_less(struct rt_waiter_node *left, + struct rt_waiter_node *right) + { ++#ifdef CONFIG_SCHED_PDS ++ return (left->deadline < right->deadline); ++#else + if (left->prio < right->prio) + return 1; + ++#ifndef CONFIG_SCHED_BMQ + /* + * If both waiters have dl_prio(), we check the deadlines of the + * associated tasks. +@@ -401,16 +405,22 @@ static __always_inline int rt_waiter_node_less(struct rt_waiter_node *left, + */ + if (dl_prio(left->prio)) + return dl_time_before(left->deadline, right->deadline); ++#endif + + return 0; ++#endif + } + + static __always_inline int rt_waiter_node_equal(struct rt_waiter_node *left, + struct rt_waiter_node *right) + { ++#ifdef CONFIG_SCHED_PDS ++ return (left->deadline == right->deadline); ++#else + if (left->prio != right->prio) + return 0; + ++#ifndef CONFIG_SCHED_BMQ + /* + * If both waiters have dl_prio(), we check the deadlines of the + * associated tasks. +@@ -419,8 +429,10 @@ static __always_inline int rt_waiter_node_equal(struct rt_waiter_node *left, + */ + if (dl_prio(left->prio)) + return left->deadline == right->deadline; ++#endif + + return 1; ++#endif + } + + static inline bool rt_mutex_steal(struct rt_mutex_waiter *waiter, +diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile +index 976092b7bd45..31d587c16ec1 100644 +--- a/kernel/sched/Makefile ++++ b/kernel/sched/Makefile +@@ -28,7 +28,12 @@ endif + # These compilation units have roughly the same size and complexity - so their + # build parallelizes well and finishes roughly at once: + # ++ifdef CONFIG_SCHED_ALT ++obj-y += alt_core.o ++obj-$(CONFIG_SCHED_DEBUG) += alt_debug.o ++else + obj-y += core.o + obj-y += fair.o ++endif + obj-y += build_policy.o + obj-y += build_utility.o +diff --git a/kernel/sched/alt_core.c b/kernel/sched/alt_core.c +new file mode 100644 +index 000000000000..b0c4ade2788c +--- /dev/null ++++ b/kernel/sched/alt_core.c +@@ -0,0 +1,8715 @@ ++/* ++ * kernel/sched/alt_core.c ++ * ++ * Core alternative kernel scheduler code and related syscalls ++ * ++ * Copyright (C) 1991-2002 Linus Torvalds ++ * ++ * 2009-08-13 Brainfuck deadline scheduling policy by Con Kolivas deletes ++ * a whole lot of those previous things. ++ * 2017-09-06 Priority and Deadline based Skip list multiple queue kernel ++ * scheduler by Alfred Chen. ++ * 2019-02-20 BMQ(BitMap Queue) kernel scheduler by Alfred Chen. ++ */ ++#include <linux/sched/clock.h> ++#include <linux/sched/cputime.h> ++#include <linux/sched/debug.h> ++#include <linux/sched/isolation.h> ++#include <linux/sched/loadavg.h> ++#include <linux/sched/mm.h> ++#include <linux/sched/nohz.h> ++#include <linux/sched/stat.h> ++#include <linux/sched/wake_q.h> ++ ++#include <linux/blkdev.h> ++#include <linux/context_tracking.h> ++#include <linux/cpuset.h> ++#include <linux/delayacct.h> ++#include <linux/init_task.h> ++#include <linux/kcov.h> ++#include <linux/kprobes.h> ++#include <linux/nmi.h> ++#include <linux/scs.h> ++ ++#include <uapi/linux/sched/types.h> ++ ++#include <asm/irq_regs.h> ++#include <asm/switch_to.h> ++ ++#define CREATE_TRACE_POINTS ++#include <trace/events/sched.h> ++#include <trace/events/ipi.h> ++#undef CREATE_TRACE_POINTS ++ ++#include "sched.h" ++ ++#include "pelt.h" ++ ++#include "../../io_uring/io-wq.h" ++#include "../smpboot.h" ++ ++EXPORT_TRACEPOINT_SYMBOL_GPL(ipi_send_cpu); ++EXPORT_TRACEPOINT_SYMBOL_GPL(ipi_send_cpumask); ++ ++/* ++ * Export tracepoints that act as a bare tracehook (ie: have no trace event ++ * associated with them) to allow external modules to probe them. ++ */ ++EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_irq_tp); ++ ++#ifdef CONFIG_SCHED_DEBUG ++#define sched_feat(x) (1) ++/* ++ * Print a warning if need_resched is set for the given duration (if ++ * LATENCY_WARN is enabled). ++ * ++ * If sysctl_resched_latency_warn_once is set, only one warning will be shown ++ * per boot. ++ */ ++__read_mostly int sysctl_resched_latency_warn_ms = 100; ++__read_mostly int sysctl_resched_latency_warn_once = 1; ++#else ++#define sched_feat(x) (0) ++#endif /* CONFIG_SCHED_DEBUG */ ++ ++#define ALT_SCHED_VERSION "v6.7-r0" ++ ++/* ++ * Compile time debug macro ++ * #define ALT_SCHED_DEBUG ++ */ ++ ++/* rt_prio(prio) defined in include/linux/sched/rt.h */ ++#define rt_task(p) rt_prio((p)->prio) ++#define rt_policy(policy) ((policy) == SCHED_FIFO || (policy) == SCHED_RR) ++#define task_has_rt_policy(p) (rt_policy((p)->policy)) ++ ++#define STOP_PRIO (MAX_RT_PRIO - 1) ++ ++/* Default time slice is 4 in ms, can be set via kernel parameter "sched_timeslice" */ ++u64 sched_timeslice_ns __read_mostly = (4 << 20); ++ ++static inline void requeue_task(struct task_struct *p, struct rq *rq, int idx); ++ ++#ifdef CONFIG_SCHED_BMQ ++#include "bmq.h" ++#endif ++#ifdef CONFIG_SCHED_PDS ++#include "pds.h" ++#endif ++ ++struct affinity_context { ++ const struct cpumask *new_mask; ++ struct cpumask *user_mask; ++ unsigned int flags; ++}; ++ ++static int __init sched_timeslice(char *str) ++{ ++ int timeslice_ms; ++ ++ get_option(&str, ×lice_ms); ++ if (2 != timeslice_ms) ++ timeslice_ms = 4; ++ sched_timeslice_ns = timeslice_ms << 20; ++ sched_timeslice_imp(timeslice_ms); ++ ++ return 0; ++} ++early_param("sched_timeslice", sched_timeslice); ++ ++/* Reschedule if less than this many μs left */ ++#define RESCHED_NS (100 << 10) ++ ++/** ++ * sched_yield_type - Choose what sort of yield sched_yield will perform. ++ * 0: No yield. ++ * 1: Deboost and requeue task. (default) ++ * 2: Set rq skip task. ++ */ ++int sched_yield_type __read_mostly = 1; ++ ++#ifdef CONFIG_SMP ++static cpumask_t sched_rq_pending_mask ____cacheline_aligned_in_smp; ++ ++DEFINE_PER_CPU_ALIGNED(cpumask_t [NR_CPU_AFFINITY_LEVELS], sched_cpu_topo_masks); ++DEFINE_PER_CPU_ALIGNED(cpumask_t *, sched_cpu_llc_mask); ++DEFINE_PER_CPU_ALIGNED(cpumask_t *, sched_cpu_topo_end_mask); ++ ++#ifdef CONFIG_SCHED_SMT ++DEFINE_STATIC_KEY_FALSE(sched_smt_present); ++EXPORT_SYMBOL_GPL(sched_smt_present); ++#endif ++ ++/* ++ * Keep a unique ID per domain (we use the first CPUs number in the cpumask of ++ * the domain), this allows us to quickly tell if two cpus are in the same cache ++ * domain, see cpus_share_cache(). ++ */ ++DEFINE_PER_CPU(int, sd_llc_id); ++#endif /* CONFIG_SMP */ ++ ++static DEFINE_MUTEX(sched_hotcpu_mutex); ++ ++DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); ++ ++#ifndef prepare_arch_switch ++# define prepare_arch_switch(next) do { } while (0) ++#endif ++#ifndef finish_arch_post_lock_switch ++# define finish_arch_post_lock_switch() do { } while (0) ++#endif ++ ++#ifdef CONFIG_SCHED_SMT ++static cpumask_t sched_sg_idle_mask ____cacheline_aligned_in_smp; ++#endif ++static cpumask_t sched_preempt_mask[SCHED_QUEUE_BITS] ____cacheline_aligned_in_smp; ++static cpumask_t *const sched_idle_mask = &sched_preempt_mask[0]; ++ ++/* task function */ ++static inline const struct cpumask *task_user_cpus(struct task_struct *p) ++{ ++ if (!p->user_cpus_ptr) ++ return cpu_possible_mask; /* &init_task.cpus_mask */ ++ return p->user_cpus_ptr; ++} ++ ++/* sched_queue related functions */ ++static inline void sched_queue_init(struct sched_queue *q) ++{ ++ int i; ++ ++ bitmap_zero(q->bitmap, SCHED_QUEUE_BITS); ++ for(i = 0; i < SCHED_LEVELS; i++) ++ INIT_LIST_HEAD(&q->heads[i]); ++} ++ ++/* ++ * Init idle task and put into queue structure of rq ++ * IMPORTANT: may be called multiple times for a single cpu ++ */ ++static inline void sched_queue_init_idle(struct sched_queue *q, ++ struct task_struct *idle) ++{ ++ idle->sq_idx = IDLE_TASK_SCHED_PRIO; ++ INIT_LIST_HEAD(&q->heads[idle->sq_idx]); ++ list_add(&idle->sq_node, &q->heads[idle->sq_idx]); ++} ++ ++static inline void ++clear_recorded_preempt_mask(int pr, int low, int high, int cpu) ++{ ++ if (low < pr && pr <= high) ++ cpumask_clear_cpu(cpu, sched_preempt_mask + SCHED_QUEUE_BITS - pr); ++} ++ ++static inline void ++set_recorded_preempt_mask(int pr, int low, int high, int cpu) ++{ ++ if (low < pr && pr <= high) ++ cpumask_set_cpu(cpu, sched_preempt_mask + SCHED_QUEUE_BITS - pr); ++} ++ ++static atomic_t sched_prio_record = ATOMIC_INIT(0); ++ ++/* water mark related functions */ ++static inline void update_sched_preempt_mask(struct rq *rq) ++{ ++ unsigned long prio = find_first_bit(rq->queue.bitmap, SCHED_QUEUE_BITS); ++ unsigned long last_prio = rq->prio; ++ int cpu, pr; ++ ++ if (prio == last_prio) ++ return; ++ ++ rq->prio = prio; ++ cpu = cpu_of(rq); ++ pr = atomic_read(&sched_prio_record); ++ ++ if (prio < last_prio) { ++ if (IDLE_TASK_SCHED_PRIO == last_prio) { ++#ifdef CONFIG_SCHED_SMT ++ if (static_branch_likely(&sched_smt_present)) ++ cpumask_andnot(&sched_sg_idle_mask, ++ &sched_sg_idle_mask, cpu_smt_mask(cpu)); ++#endif ++ cpumask_clear_cpu(cpu, sched_idle_mask); ++ last_prio -= 2; ++ } ++ clear_recorded_preempt_mask(pr, prio, last_prio, cpu); ++ ++ return; ++ } ++ /* last_prio < prio */ ++ if (IDLE_TASK_SCHED_PRIO == prio) { ++#ifdef CONFIG_SCHED_SMT ++ if (static_branch_likely(&sched_smt_present) && ++ cpumask_intersects(cpu_smt_mask(cpu), sched_idle_mask)) ++ cpumask_or(&sched_sg_idle_mask, ++ &sched_sg_idle_mask, cpu_smt_mask(cpu)); ++#endif ++ cpumask_set_cpu(cpu, sched_idle_mask); ++ prio -= 2; ++ } ++ set_recorded_preempt_mask(pr, last_prio, prio, cpu); ++} ++ ++/* ++ * This routine assume that the idle task always in queue ++ */ ++static inline struct task_struct *sched_rq_first_task(struct rq *rq) ++{ ++ const struct list_head *head = &rq->queue.heads[sched_prio2idx(rq->prio, rq)]; ++ ++ return list_first_entry(head, struct task_struct, sq_node); ++} ++ ++static inline struct task_struct * ++sched_rq_next_task(struct task_struct *p, struct rq *rq) ++{ ++ unsigned long idx = p->sq_idx; ++ struct list_head *head = &rq->queue.heads[idx]; ++ ++ if (list_is_last(&p->sq_node, head)) { ++ idx = find_next_bit(rq->queue.bitmap, SCHED_QUEUE_BITS, ++ sched_idx2prio(idx, rq) + 1); ++ head = &rq->queue.heads[sched_prio2idx(idx, rq)]; ++ ++ return list_first_entry(head, struct task_struct, sq_node); ++ } ++ ++ return list_next_entry(p, sq_node); ++} ++ ++static inline struct task_struct *rq_runnable_task(struct rq *rq) ++{ ++ struct task_struct *next = sched_rq_first_task(rq); ++ ++ if (unlikely(next == rq->skip)) ++ next = sched_rq_next_task(next, rq); ++ ++ return next; ++} ++ ++/* ++ * Serialization rules: ++ * ++ * Lock order: ++ * ++ * p->pi_lock ++ * rq->lock ++ * hrtimer_cpu_base->lock (hrtimer_start() for bandwidth controls) ++ * ++ * rq1->lock ++ * rq2->lock where: rq1 < rq2 ++ * ++ * Regular state: ++ * ++ * Normal scheduling state is serialized by rq->lock. __schedule() takes the ++ * local CPU's rq->lock, it optionally removes the task from the runqueue and ++ * always looks at the local rq data structures to find the most eligible task ++ * to run next. ++ * ++ * Task enqueue is also under rq->lock, possibly taken from another CPU. ++ * Wakeups from another LLC domain might use an IPI to transfer the enqueue to ++ * the local CPU to avoid bouncing the runqueue state around [ see ++ * ttwu_queue_wakelist() ] ++ * ++ * Task wakeup, specifically wakeups that involve migration, are horribly ++ * complicated to avoid having to take two rq->locks. ++ * ++ * Special state: ++ * ++ * System-calls and anything external will use task_rq_lock() which acquires ++ * both p->pi_lock and rq->lock. As a consequence the state they change is ++ * stable while holding either lock: ++ * ++ * - sched_setaffinity()/ ++ * set_cpus_allowed_ptr(): p->cpus_ptr, p->nr_cpus_allowed ++ * - set_user_nice(): p->se.load, p->*prio ++ * - __sched_setscheduler(): p->sched_class, p->policy, p->*prio, ++ * p->se.load, p->rt_priority, ++ * p->dl.dl_{runtime, deadline, period, flags, bw, density} ++ * - sched_setnuma(): p->numa_preferred_nid ++ * - sched_move_task(): p->sched_task_group ++ * - uclamp_update_active() p->uclamp* ++ * ++ * p->state <- TASK_*: ++ * ++ * is changed locklessly using set_current_state(), __set_current_state() or ++ * set_special_state(), see their respective comments, or by ++ * try_to_wake_up(). This latter uses p->pi_lock to serialize against ++ * concurrent self. ++ * ++ * p->on_rq <- { 0, 1 = TASK_ON_RQ_QUEUED, 2 = TASK_ON_RQ_MIGRATING }: ++ * ++ * is set by activate_task() and cleared by deactivate_task(), under ++ * rq->lock. Non-zero indicates the task is runnable, the special ++ * ON_RQ_MIGRATING state is used for migration without holding both ++ * rq->locks. It indicates task_cpu() is not stable, see task_rq_lock(). ++ * ++ * p->on_cpu <- { 0, 1 }: ++ * ++ * is set by prepare_task() and cleared by finish_task() such that it will be ++ * set before p is scheduled-in and cleared after p is scheduled-out, both ++ * under rq->lock. Non-zero indicates the task is running on its CPU. ++ * ++ * [ The astute reader will observe that it is possible for two tasks on one ++ * CPU to have ->on_cpu = 1 at the same time. ] ++ * ++ * task_cpu(p): is changed by set_task_cpu(), the rules are: ++ * ++ * - Don't call set_task_cpu() on a blocked task: ++ * ++ * We don't care what CPU we're not running on, this simplifies hotplug, ++ * the CPU assignment of blocked tasks isn't required to be valid. ++ * ++ * - for try_to_wake_up(), called under p->pi_lock: ++ * ++ * This allows try_to_wake_up() to only take one rq->lock, see its comment. ++ * ++ * - for migration called under rq->lock: ++ * [ see task_on_rq_migrating() in task_rq_lock() ] ++ * ++ * o move_queued_task() ++ * o detach_task() ++ * ++ * - for migration called under double_rq_lock(): ++ * ++ * o __migrate_swap_task() ++ * o push_rt_task() / pull_rt_task() ++ * o push_dl_task() / pull_dl_task() ++ * o dl_task_offline_migration() ++ * ++ */ ++ ++/* ++ * Context: p->pi_lock ++ */ ++static inline struct rq ++*__task_access_lock(struct task_struct *p, raw_spinlock_t **plock) ++{ ++ struct rq *rq; ++ for (;;) { ++ rq = task_rq(p); ++ if (p->on_cpu || task_on_rq_queued(p)) { ++ raw_spin_lock(&rq->lock); ++ if (likely((p->on_cpu || task_on_rq_queued(p)) ++ && rq == task_rq(p))) { ++ *plock = &rq->lock; ++ return rq; ++ } ++ raw_spin_unlock(&rq->lock); ++ } else if (task_on_rq_migrating(p)) { ++ do { ++ cpu_relax(); ++ } while (unlikely(task_on_rq_migrating(p))); ++ } else { ++ *plock = NULL; ++ return rq; ++ } ++ } ++} ++ ++static inline void ++__task_access_unlock(struct task_struct *p, raw_spinlock_t *lock) ++{ ++ if (NULL != lock) ++ raw_spin_unlock(lock); ++} ++ ++static inline struct rq ++*task_access_lock_irqsave(struct task_struct *p, raw_spinlock_t **plock, ++ unsigned long *flags) ++{ ++ struct rq *rq; ++ for (;;) { ++ rq = task_rq(p); ++ if (p->on_cpu || task_on_rq_queued(p)) { ++ raw_spin_lock_irqsave(&rq->lock, *flags); ++ if (likely((p->on_cpu || task_on_rq_queued(p)) ++ && rq == task_rq(p))) { ++ *plock = &rq->lock; ++ return rq; ++ } ++ raw_spin_unlock_irqrestore(&rq->lock, *flags); ++ } else if (task_on_rq_migrating(p)) { ++ do { ++ cpu_relax(); ++ } while (unlikely(task_on_rq_migrating(p))); ++ } else { ++ raw_spin_lock_irqsave(&p->pi_lock, *flags); ++ if (likely(!p->on_cpu && !p->on_rq && ++ rq == task_rq(p))) { ++ *plock = &p->pi_lock; ++ return rq; ++ } ++ raw_spin_unlock_irqrestore(&p->pi_lock, *flags); ++ } ++ } ++} ++ ++static inline void ++task_access_unlock_irqrestore(struct task_struct *p, raw_spinlock_t *lock, ++ unsigned long *flags) ++{ ++ raw_spin_unlock_irqrestore(lock, *flags); ++} ++ ++/* ++ * __task_rq_lock - lock the rq @p resides on. ++ */ ++struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) ++ __acquires(rq->lock) ++{ ++ struct rq *rq; ++ ++ lockdep_assert_held(&p->pi_lock); ++ ++ for (;;) { ++ rq = task_rq(p); ++ raw_spin_lock(&rq->lock); ++ if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) ++ return rq; ++ raw_spin_unlock(&rq->lock); ++ ++ while (unlikely(task_on_rq_migrating(p))) ++ cpu_relax(); ++ } ++} ++ ++/* ++ * task_rq_lock - lock p->pi_lock and lock the rq @p resides on. ++ */ ++struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) ++ __acquires(p->pi_lock) ++ __acquires(rq->lock) ++{ ++ struct rq *rq; ++ ++ for (;;) { ++ raw_spin_lock_irqsave(&p->pi_lock, rf->flags); ++ rq = task_rq(p); ++ raw_spin_lock(&rq->lock); ++ /* ++ * move_queued_task() task_rq_lock() ++ * ++ * ACQUIRE (rq->lock) ++ * [S] ->on_rq = MIGRATING [L] rq = task_rq() ++ * WMB (__set_task_cpu()) ACQUIRE (rq->lock); ++ * [S] ->cpu = new_cpu [L] task_rq() ++ * [L] ->on_rq ++ * RELEASE (rq->lock) ++ * ++ * If we observe the old CPU in task_rq_lock(), the acquire of ++ * the old rq->lock will fully serialize against the stores. ++ * ++ * If we observe the new CPU in task_rq_lock(), the address ++ * dependency headed by '[L] rq = task_rq()' and the acquire ++ * will pair with the WMB to ensure we then also see migrating. ++ */ ++ if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) { ++ return rq; ++ } ++ raw_spin_unlock(&rq->lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); ++ ++ while (unlikely(task_on_rq_migrating(p))) ++ cpu_relax(); ++ } ++} ++ ++static inline void ++rq_lock_irqsave(struct rq *rq, struct rq_flags *rf) ++ __acquires(rq->lock) ++{ ++ raw_spin_lock_irqsave(&rq->lock, rf->flags); ++} ++ ++static inline void ++rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf) ++ __releases(rq->lock) ++{ ++ raw_spin_unlock_irqrestore(&rq->lock, rf->flags); ++} ++ ++DEFINE_LOCK_GUARD_1(rq_lock_irqsave, struct rq, ++ rq_lock_irqsave(_T->lock, &_T->rf), ++ rq_unlock_irqrestore(_T->lock, &_T->rf), ++ struct rq_flags rf) ++ ++void raw_spin_rq_lock_nested(struct rq *rq, int subclass) ++{ ++ raw_spinlock_t *lock; ++ ++ /* Matches synchronize_rcu() in __sched_core_enable() */ ++ preempt_disable(); ++ ++ for (;;) { ++ lock = __rq_lockp(rq); ++ raw_spin_lock_nested(lock, subclass); ++ if (likely(lock == __rq_lockp(rq))) { ++ /* preempt_count *MUST* be > 1 */ ++ preempt_enable_no_resched(); ++ return; ++ } ++ raw_spin_unlock(lock); ++ } ++} ++ ++void raw_spin_rq_unlock(struct rq *rq) ++{ ++ raw_spin_unlock(rq_lockp(rq)); ++} ++ ++/* ++ * RQ-clock updating methods: ++ */ ++ ++static void update_rq_clock_task(struct rq *rq, s64 delta) ++{ ++/* ++ * In theory, the compile should just see 0 here, and optimize out the call ++ * to sched_rt_avg_update. But I don't trust it... ++ */ ++ s64 __maybe_unused steal = 0, irq_delta = 0; ++ ++#ifdef CONFIG_IRQ_TIME_ACCOUNTING ++ irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time; ++ ++ /* ++ * Since irq_time is only updated on {soft,}irq_exit, we might run into ++ * this case when a previous update_rq_clock() happened inside a ++ * {soft,}irq region. ++ * ++ * When this happens, we stop ->clock_task and only update the ++ * prev_irq_time stamp to account for the part that fit, so that a next ++ * update will consume the rest. This ensures ->clock_task is ++ * monotonic. ++ * ++ * It does however cause some slight miss-attribution of {soft,}irq ++ * time, a more accurate solution would be to update the irq_time using ++ * the current rq->clock timestamp, except that would require using ++ * atomic ops. ++ */ ++ if (irq_delta > delta) ++ irq_delta = delta; ++ ++ rq->prev_irq_time += irq_delta; ++ delta -= irq_delta; ++ delayacct_irq(rq->curr, irq_delta); ++#endif ++#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING ++ if (static_key_false((¶virt_steal_rq_enabled))) { ++ steal = paravirt_steal_clock(cpu_of(rq)); ++ steal -= rq->prev_steal_time_rq; ++ ++ if (unlikely(steal > delta)) ++ steal = delta; ++ ++ rq->prev_steal_time_rq += steal; ++ delta -= steal; ++ } ++#endif ++ ++ rq->clock_task += delta; ++ ++#ifdef CONFIG_HAVE_SCHED_AVG_IRQ ++ if ((irq_delta + steal)) ++ update_irq_load_avg(rq, irq_delta + steal); ++#endif ++} ++ ++static inline void update_rq_clock(struct rq *rq) ++{ ++ s64 delta = sched_clock_cpu(cpu_of(rq)) - rq->clock; ++ ++ if (unlikely(delta <= 0)) ++ return; ++ rq->clock += delta; ++ sched_update_rq_clock(rq); ++ update_rq_clock_task(rq, delta); ++} ++ ++/* ++ * RQ Load update routine ++ */ ++#define RQ_LOAD_HISTORY_BITS (sizeof(s32) * 8ULL) ++#define RQ_UTIL_SHIFT (8) ++#define RQ_LOAD_HISTORY_TO_UTIL(l) (((l) >> (RQ_LOAD_HISTORY_BITS - 1 - RQ_UTIL_SHIFT)) & 0xff) ++ ++#define LOAD_BLOCK(t) ((t) >> 17) ++#define LOAD_HALF_BLOCK(t) ((t) >> 16) ++#define BLOCK_MASK(t) ((t) & ((0x01 << 18) - 1)) ++#define LOAD_BLOCK_BIT(b) (1UL << (RQ_LOAD_HISTORY_BITS - 1 - (b))) ++#define CURRENT_LOAD_BIT LOAD_BLOCK_BIT(0) ++ ++static inline void rq_load_update(struct rq *rq) ++{ ++ u64 time = rq->clock; ++ u64 delta = min(LOAD_BLOCK(time) - LOAD_BLOCK(rq->load_stamp), ++ RQ_LOAD_HISTORY_BITS - 1); ++ u64 prev = !!(rq->load_history & CURRENT_LOAD_BIT); ++ u64 curr = !!rq->nr_running; ++ ++ if (delta) { ++ rq->load_history = rq->load_history >> delta; ++ ++ if (delta < RQ_UTIL_SHIFT) { ++ rq->load_block += (~BLOCK_MASK(rq->load_stamp)) * prev; ++ if (!!LOAD_HALF_BLOCK(rq->load_block) ^ curr) ++ rq->load_history ^= LOAD_BLOCK_BIT(delta); ++ } ++ ++ rq->load_block = BLOCK_MASK(time) * prev; ++ } else { ++ rq->load_block += (time - rq->load_stamp) * prev; ++ } ++ if (prev ^ curr) ++ rq->load_history ^= CURRENT_LOAD_BIT; ++ rq->load_stamp = time; ++} ++ ++unsigned long rq_load_util(struct rq *rq, unsigned long max) ++{ ++ return RQ_LOAD_HISTORY_TO_UTIL(rq->load_history) * (max >> RQ_UTIL_SHIFT); ++} ++ ++#ifdef CONFIG_SMP ++unsigned long sched_cpu_util(int cpu) ++{ ++ return rq_load_util(cpu_rq(cpu), arch_scale_cpu_capacity(cpu)); ++} ++#endif /* CONFIG_SMP */ ++ ++#ifdef CONFIG_CPU_FREQ ++/** ++ * cpufreq_update_util - Take a note about CPU utilization changes. ++ * @rq: Runqueue to carry out the update for. ++ * @flags: Update reason flags. ++ * ++ * This function is called by the scheduler on the CPU whose utilization is ++ * being updated. ++ * ++ * It can only be called from RCU-sched read-side critical sections. ++ * ++ * The way cpufreq is currently arranged requires it to evaluate the CPU ++ * performance state (frequency/voltage) on a regular basis to prevent it from ++ * being stuck in a completely inadequate performance level for too long. ++ * That is not guaranteed to happen if the updates are only triggered from CFS ++ * and DL, though, because they may not be coming in if only RT tasks are ++ * active all the time (or there are RT tasks only). ++ * ++ * As a workaround for that issue, this function is called periodically by the ++ * RT sched class to trigger extra cpufreq updates to prevent it from stalling, ++ * but that really is a band-aid. Going forward it should be replaced with ++ * solutions targeted more specifically at RT tasks. ++ */ ++static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) ++{ ++ struct update_util_data *data; ++ ++#ifdef CONFIG_SMP ++ rq_load_update(rq); ++#endif ++ data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data, ++ cpu_of(rq))); ++ if (data) ++ data->func(data, rq_clock(rq), flags); ++} ++#else ++static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) ++{ ++#ifdef CONFIG_SMP ++ rq_load_update(rq); ++#endif ++} ++#endif /* CONFIG_CPU_FREQ */ ++ ++#ifdef CONFIG_NO_HZ_FULL ++/* ++ * Tick may be needed by tasks in the runqueue depending on their policy and ++ * requirements. If tick is needed, lets send the target an IPI to kick it out ++ * of nohz mode if necessary. ++ */ ++static inline void sched_update_tick_dependency(struct rq *rq) ++{ ++ int cpu = cpu_of(rq); ++ ++ if (!tick_nohz_full_cpu(cpu)) ++ return; ++ ++ if (rq->nr_running < 2) ++ tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED); ++ else ++ tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED); ++} ++#else /* !CONFIG_NO_HZ_FULL */ ++static inline void sched_update_tick_dependency(struct rq *rq) { } ++#endif ++ ++bool sched_task_on_rq(struct task_struct *p) ++{ ++ return task_on_rq_queued(p); ++} ++ ++unsigned long get_wchan(struct task_struct *p) ++{ ++ unsigned long ip = 0; ++ unsigned int state; ++ ++ if (!p || p == current) ++ return 0; ++ ++ /* Only get wchan if task is blocked and we can keep it that way. */ ++ raw_spin_lock_irq(&p->pi_lock); ++ state = READ_ONCE(p->__state); ++ smp_rmb(); /* see try_to_wake_up() */ ++ if (state != TASK_RUNNING && state != TASK_WAKING && !p->on_rq) ++ ip = __get_wchan(p); ++ raw_spin_unlock_irq(&p->pi_lock); ++ ++ return ip; ++} ++ ++/* ++ * Add/Remove/Requeue task to/from the runqueue routines ++ * Context: rq->lock ++ */ ++#define __SCHED_DEQUEUE_TASK(p, rq, flags, func) \ ++ sched_info_dequeue(rq, p); \ ++ \ ++ list_del(&p->sq_node); \ ++ if (list_empty(&rq->queue.heads[p->sq_idx])) { \ ++ clear_bit(sched_idx2prio(p->sq_idx, rq), rq->queue.bitmap); \ ++ func; \ ++ } ++ ++#define __SCHED_ENQUEUE_TASK(p, rq, flags) \ ++ sched_info_enqueue(rq, p); \ ++ \ ++ p->sq_idx = task_sched_prio_idx(p, rq); \ ++ list_add_tail(&p->sq_node, &rq->queue.heads[p->sq_idx]); \ ++ set_bit(sched_idx2prio(p->sq_idx, rq), rq->queue.bitmap); ++ ++static inline void dequeue_task(struct task_struct *p, struct rq *rq, int flags) ++{ ++#ifdef ALT_SCHED_DEBUG ++ lockdep_assert_held(&rq->lock); ++ ++ /*printk(KERN_INFO "sched: dequeue(%d) %px %016llx\n", cpu_of(rq), p, p->deadline);*/ ++ WARN_ONCE(task_rq(p) != rq, "sched: dequeue task reside on cpu%d from cpu%d\n", ++ task_cpu(p), cpu_of(rq)); ++#endif ++ ++ __SCHED_DEQUEUE_TASK(p, rq, flags, update_sched_preempt_mask(rq)); ++ --rq->nr_running; ++#ifdef CONFIG_SMP ++ if (1 == rq->nr_running) ++ cpumask_clear_cpu(cpu_of(rq), &sched_rq_pending_mask); ++#endif ++ ++ sched_update_tick_dependency(rq); ++} ++ ++static inline void enqueue_task(struct task_struct *p, struct rq *rq, int flags) ++{ ++#ifdef ALT_SCHED_DEBUG ++ lockdep_assert_held(&rq->lock); ++ ++ /*printk(KERN_INFO "sched: enqueue(%d) %px %d\n", cpu_of(rq), p, p->prio);*/ ++ WARN_ONCE(task_rq(p) != rq, "sched: enqueue task reside on cpu%d to cpu%d\n", ++ task_cpu(p), cpu_of(rq)); ++#endif ++ ++ __SCHED_ENQUEUE_TASK(p, rq, flags); ++ update_sched_preempt_mask(rq); ++ ++rq->nr_running; ++#ifdef CONFIG_SMP ++ if (2 == rq->nr_running) ++ cpumask_set_cpu(cpu_of(rq), &sched_rq_pending_mask); ++#endif ++ ++ sched_update_tick_dependency(rq); ++} ++ ++static inline void requeue_task(struct task_struct *p, struct rq *rq, int idx) ++{ ++#ifdef ALT_SCHED_DEBUG ++ lockdep_assert_held(&rq->lock); ++ /*printk(KERN_INFO "sched: requeue(%d) %px %016llx\n", cpu_of(rq), p, p->deadline);*/ ++ WARN_ONCE(task_rq(p) != rq, "sched: cpu[%d] requeue task reside on cpu%d\n", ++ cpu_of(rq), task_cpu(p)); ++#endif ++ ++ list_del(&p->sq_node); ++ list_add_tail(&p->sq_node, &rq->queue.heads[idx]); ++ if (idx != p->sq_idx) { ++ if (list_empty(&rq->queue.heads[p->sq_idx])) ++ clear_bit(sched_idx2prio(p->sq_idx, rq), rq->queue.bitmap); ++ p->sq_idx = idx; ++ set_bit(sched_idx2prio(p->sq_idx, rq), rq->queue.bitmap); ++ update_sched_preempt_mask(rq); ++ } ++} ++ ++/* ++ * cmpxchg based fetch_or, macro so it works for different integer types ++ */ ++#define fetch_or(ptr, mask) \ ++ ({ \ ++ typeof(ptr) _ptr = (ptr); \ ++ typeof(mask) _mask = (mask); \ ++ typeof(*_ptr) _val = *_ptr; \ ++ \ ++ do { \ ++ } while (!try_cmpxchg(_ptr, &_val, _val | _mask)); \ ++ _val; \ ++}) ++ ++#if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG) ++/* ++ * Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG, ++ * this avoids any races wrt polling state changes and thereby avoids ++ * spurious IPIs. ++ */ ++static inline bool set_nr_and_not_polling(struct task_struct *p) ++{ ++ struct thread_info *ti = task_thread_info(p); ++ return !(fetch_or(&ti->flags, _TIF_NEED_RESCHED) & _TIF_POLLING_NRFLAG); ++} ++ ++/* ++ * Atomically set TIF_NEED_RESCHED if TIF_POLLING_NRFLAG is set. ++ * ++ * If this returns true, then the idle task promises to call ++ * sched_ttwu_pending() and reschedule soon. ++ */ ++static bool set_nr_if_polling(struct task_struct *p) ++{ ++ struct thread_info *ti = task_thread_info(p); ++ typeof(ti->flags) val = READ_ONCE(ti->flags); ++ ++ do { ++ if (!(val & _TIF_POLLING_NRFLAG)) ++ return false; ++ if (val & _TIF_NEED_RESCHED) ++ return true; ++ } while (!try_cmpxchg(&ti->flags, &val, val | _TIF_NEED_RESCHED)); ++ ++ return true; ++} ++ ++#else ++static inline bool set_nr_and_not_polling(struct task_struct *p) ++{ ++ set_tsk_need_resched(p); ++ return true; ++} ++ ++#ifdef CONFIG_SMP ++static inline bool set_nr_if_polling(struct task_struct *p) ++{ ++ return false; ++} ++#endif ++#endif ++ ++static bool __wake_q_add(struct wake_q_head *head, struct task_struct *task) ++{ ++ struct wake_q_node *node = &task->wake_q; ++ ++ /* ++ * Atomically grab the task, if ->wake_q is !nil already it means ++ * it's already queued (either by us or someone else) and will get the ++ * wakeup due to that. ++ * ++ * In order to ensure that a pending wakeup will observe our pending ++ * state, even in the failed case, an explicit smp_mb() must be used. ++ */ ++ smp_mb__before_atomic(); ++ if (unlikely(cmpxchg_relaxed(&node->next, NULL, WAKE_Q_TAIL))) ++ return false; ++ ++ /* ++ * The head is context local, there can be no concurrency. ++ */ ++ *head->lastp = node; ++ head->lastp = &node->next; ++ return true; ++} ++ ++/** ++ * wake_q_add() - queue a wakeup for 'later' waking. ++ * @head: the wake_q_head to add @task to ++ * @task: the task to queue for 'later' wakeup ++ * ++ * Queue a task for later wakeup, most likely by the wake_up_q() call in the ++ * same context, _HOWEVER_ this is not guaranteed, the wakeup can come ++ * instantly. ++ * ++ * This function must be used as-if it were wake_up_process(); IOW the task ++ * must be ready to be woken at this location. ++ */ ++void wake_q_add(struct wake_q_head *head, struct task_struct *task) ++{ ++ if (__wake_q_add(head, task)) ++ get_task_struct(task); ++} ++ ++/** ++ * wake_q_add_safe() - safely queue a wakeup for 'later' waking. ++ * @head: the wake_q_head to add @task to ++ * @task: the task to queue for 'later' wakeup ++ * ++ * Queue a task for later wakeup, most likely by the wake_up_q() call in the ++ * same context, _HOWEVER_ this is not guaranteed, the wakeup can come ++ * instantly. ++ * ++ * This function must be used as-if it were wake_up_process(); IOW the task ++ * must be ready to be woken at this location. ++ * ++ * This function is essentially a task-safe equivalent to wake_q_add(). Callers ++ * that already hold reference to @task can call the 'safe' version and trust ++ * wake_q to do the right thing depending whether or not the @task is already ++ * queued for wakeup. ++ */ ++void wake_q_add_safe(struct wake_q_head *head, struct task_struct *task) ++{ ++ if (!__wake_q_add(head, task)) ++ put_task_struct(task); ++} ++ ++void wake_up_q(struct wake_q_head *head) ++{ ++ struct wake_q_node *node = head->first; ++ ++ while (node != WAKE_Q_TAIL) { ++ struct task_struct *task; ++ ++ task = container_of(node, struct task_struct, wake_q); ++ /* task can safely be re-inserted now: */ ++ node = node->next; ++ task->wake_q.next = NULL; ++ ++ /* ++ * wake_up_process() executes a full barrier, which pairs with ++ * the queueing in wake_q_add() so as not to miss wakeups. ++ */ ++ wake_up_process(task); ++ put_task_struct(task); ++ } ++} ++ ++/* ++ * resched_curr - mark rq's current task 'to be rescheduled now'. ++ * ++ * On UP this means the setting of the need_resched flag, on SMP it ++ * might also involve a cross-CPU call to trigger the scheduler on ++ * the target CPU. ++ */ ++void resched_curr(struct rq *rq) ++{ ++ struct task_struct *curr = rq->curr; ++ int cpu; ++ ++ lockdep_assert_held(&rq->lock); ++ ++ if (test_tsk_need_resched(curr)) ++ return; ++ ++ cpu = cpu_of(rq); ++ if (cpu == smp_processor_id()) { ++ set_tsk_need_resched(curr); ++ set_preempt_need_resched(); ++ return; ++ } ++ ++ if (set_nr_and_not_polling(curr)) ++ smp_send_reschedule(cpu); ++ else ++ trace_sched_wake_idle_without_ipi(cpu); ++} ++ ++void resched_cpu(int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ unsigned long flags; ++ ++ raw_spin_lock_irqsave(&rq->lock, flags); ++ if (cpu_online(cpu) || cpu == smp_processor_id()) ++ resched_curr(cpu_rq(cpu)); ++ raw_spin_unlock_irqrestore(&rq->lock, flags); ++} ++ ++#ifdef CONFIG_SMP ++#ifdef CONFIG_NO_HZ_COMMON ++void nohz_balance_enter_idle(int cpu) {} ++ ++void select_nohz_load_balancer(int stop_tick) {} ++ ++void set_cpu_sd_state_idle(void) {} ++ ++/* ++ * In the semi idle case, use the nearest busy CPU for migrating timers ++ * from an idle CPU. This is good for power-savings. ++ * ++ * We don't do similar optimization for completely idle system, as ++ * selecting an idle CPU will add more delays to the timers than intended ++ * (as that CPU's timer base may not be uptodate wrt jiffies etc). ++ */ ++int get_nohz_timer_target(void) ++{ ++ int i, cpu = smp_processor_id(), default_cpu = -1; ++ struct cpumask *mask; ++ const struct cpumask *hk_mask; ++ ++ if (housekeeping_cpu(cpu, HK_TYPE_TIMER)) { ++ if (!idle_cpu(cpu)) ++ return cpu; ++ default_cpu = cpu; ++ } ++ ++ hk_mask = housekeeping_cpumask(HK_TYPE_TIMER); ++ ++ for (mask = per_cpu(sched_cpu_topo_masks, cpu) + 1; ++ mask < per_cpu(sched_cpu_topo_end_mask, cpu); mask++) ++ for_each_cpu_and(i, mask, hk_mask) ++ if (!idle_cpu(i)) ++ return i; ++ ++ if (default_cpu == -1) ++ default_cpu = housekeeping_any_cpu(HK_TYPE_TIMER); ++ cpu = default_cpu; ++ ++ return cpu; ++} ++ ++/* ++ * When add_timer_on() enqueues a timer into the timer wheel of an ++ * idle CPU then this timer might expire before the next timer event ++ * which is scheduled to wake up that CPU. In case of a completely ++ * idle system the next event might even be infinite time into the ++ * future. wake_up_idle_cpu() ensures that the CPU is woken up and ++ * leaves the inner idle loop so the newly added timer is taken into ++ * account when the CPU goes back to idle and evaluates the timer ++ * wheel for the next timer event. ++ */ ++static inline void wake_up_idle_cpu(int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ ++ if (cpu == smp_processor_id()) ++ return; ++ ++ if (set_nr_and_not_polling(rq->idle)) ++ smp_send_reschedule(cpu); ++ else ++ trace_sched_wake_idle_without_ipi(cpu); ++} ++ ++static inline bool wake_up_full_nohz_cpu(int cpu) ++{ ++ /* ++ * We just need the target to call irq_exit() and re-evaluate ++ * the next tick. The nohz full kick at least implies that. ++ * If needed we can still optimize that later with an ++ * empty IRQ. ++ */ ++ if (cpu_is_offline(cpu)) ++ return true; /* Don't try to wake offline CPUs. */ ++ if (tick_nohz_full_cpu(cpu)) { ++ if (cpu != smp_processor_id() || ++ tick_nohz_tick_stopped()) ++ tick_nohz_full_kick_cpu(cpu); ++ return true; ++ } ++ ++ return false; ++} ++ ++void wake_up_nohz_cpu(int cpu) ++{ ++ if (!wake_up_full_nohz_cpu(cpu)) ++ wake_up_idle_cpu(cpu); ++} ++ ++static void nohz_csd_func(void *info) ++{ ++ struct rq *rq = info; ++ int cpu = cpu_of(rq); ++ unsigned int flags; ++ ++ /* ++ * Release the rq::nohz_csd. ++ */ ++ flags = atomic_fetch_andnot(NOHZ_KICK_MASK, nohz_flags(cpu)); ++ WARN_ON(!(flags & NOHZ_KICK_MASK)); ++ ++ rq->idle_balance = idle_cpu(cpu); ++ if (rq->idle_balance && !need_resched()) { ++ rq->nohz_idle_balance = flags; ++ raise_softirq_irqoff(SCHED_SOFTIRQ); ++ } ++} ++ ++#endif /* CONFIG_NO_HZ_COMMON */ ++#endif /* CONFIG_SMP */ ++ ++static inline void wakeup_preempt(struct rq *rq) ++{ ++ if (sched_rq_first_task(rq) != rq->curr) ++ resched_curr(rq); ++} ++ ++static __always_inline ++int __task_state_match(struct task_struct *p, unsigned int state) ++{ ++ if (READ_ONCE(p->__state) & state) ++ return 1; ++ ++ if (READ_ONCE(p->saved_state) & state) ++ return -1; ++ ++ return 0; ++} ++ ++static __always_inline ++int task_state_match(struct task_struct *p, unsigned int state) ++{ ++ /* ++ * Serialize against current_save_and_set_rtlock_wait_state(), ++ * current_restore_rtlock_saved_state(), and __refrigerator(). ++ */ ++ guard(raw_spinlock_irq)(&p->pi_lock); ++ ++ return __task_state_match(p, state); ++} ++ ++/* ++ * wait_task_inactive - wait for a thread to unschedule. ++ * ++ * Wait for the thread to block in any of the states set in @match_state. ++ * If it changes, i.e. @p might have woken up, then return zero. When we ++ * succeed in waiting for @p to be off its CPU, we return a positive number ++ * (its total switch count). If a second call a short while later returns the ++ * same number, the caller can be sure that @p has remained unscheduled the ++ * whole time. ++ * ++ * The caller must ensure that the task *will* unschedule sometime soon, ++ * else this function might spin for a *long* time. This function can't ++ * be called with interrupts off, or it may introduce deadlock with ++ * smp_call_function() if an IPI is sent by the same process we are ++ * waiting to become inactive. ++ */ ++unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state) ++{ ++ unsigned long flags; ++ int running, queued, match; ++ unsigned long ncsw; ++ struct rq *rq; ++ raw_spinlock_t *lock; ++ ++ for (;;) { ++ rq = task_rq(p); ++ ++ /* ++ * If the task is actively running on another CPU ++ * still, just relax and busy-wait without holding ++ * any locks. ++ * ++ * NOTE! Since we don't hold any locks, it's not ++ * even sure that "rq" stays as the right runqueue! ++ * But we don't care, since this will return false ++ * if the runqueue has changed and p is actually now ++ * running somewhere else! ++ */ ++ while (task_on_cpu(p)) { ++ if (!task_state_match(p, match_state)) ++ return 0; ++ cpu_relax(); ++ } ++ ++ /* ++ * Ok, time to look more closely! We need the rq ++ * lock now, to be *sure*. If we're wrong, we'll ++ * just go back and repeat. ++ */ ++ task_access_lock_irqsave(p, &lock, &flags); ++ trace_sched_wait_task(p); ++ running = task_on_cpu(p); ++ queued = p->on_rq; ++ ncsw = 0; ++ if ((match = __task_state_match(p, match_state))) { ++ /* ++ * When matching on p->saved_state, consider this task ++ * still queued so it will wait. ++ */ ++ if (match < 0) ++ queued = 1; ++ ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ ++ } ++ task_access_unlock_irqrestore(p, lock, &flags); ++ ++ /* ++ * If it changed from the expected state, bail out now. ++ */ ++ if (unlikely(!ncsw)) ++ break; ++ ++ /* ++ * Was it really running after all now that we ++ * checked with the proper locks actually held? ++ * ++ * Oops. Go back and try again.. ++ */ ++ if (unlikely(running)) { ++ cpu_relax(); ++ continue; ++ } ++ ++ /* ++ * It's not enough that it's not actively running, ++ * it must be off the runqueue _entirely_, and not ++ * preempted! ++ * ++ * So if it was still runnable (but just not actively ++ * running right now), it's preempted, and we should ++ * yield - it could be a while. ++ */ ++ if (unlikely(queued)) { ++ ktime_t to = NSEC_PER_SEC / HZ; ++ ++ set_current_state(TASK_UNINTERRUPTIBLE); ++ schedule_hrtimeout(&to, HRTIMER_MODE_REL_HARD); ++ continue; ++ } ++ ++ /* ++ * Ahh, all good. It wasn't running, and it wasn't ++ * runnable, which means that it will never become ++ * running in the future either. We're all done! ++ */ ++ break; ++ } ++ ++ return ncsw; ++} ++ ++#ifdef CONFIG_SCHED_HRTICK ++/* ++ * Use HR-timers to deliver accurate preemption points. ++ */ ++ ++static void hrtick_clear(struct rq *rq) ++{ ++ if (hrtimer_active(&rq->hrtick_timer)) ++ hrtimer_cancel(&rq->hrtick_timer); ++} ++ ++/* ++ * High-resolution timer tick. ++ * Runs from hardirq context with interrupts disabled. ++ */ ++static enum hrtimer_restart hrtick(struct hrtimer *timer) ++{ ++ struct rq *rq = container_of(timer, struct rq, hrtick_timer); ++ ++ WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); ++ ++ raw_spin_lock(&rq->lock); ++ resched_curr(rq); ++ raw_spin_unlock(&rq->lock); ++ ++ return HRTIMER_NORESTART; ++} ++ ++/* ++ * Use hrtick when: ++ * - enabled by features ++ * - hrtimer is actually high res ++ */ ++static inline int hrtick_enabled(struct rq *rq) ++{ ++ /** ++ * Alt schedule FW doesn't support sched_feat yet ++ if (!sched_feat(HRTICK)) ++ return 0; ++ */ ++ if (!cpu_active(cpu_of(rq))) ++ return 0; ++ return hrtimer_is_hres_active(&rq->hrtick_timer); ++} ++ ++#ifdef CONFIG_SMP ++ ++static void __hrtick_restart(struct rq *rq) ++{ ++ struct hrtimer *timer = &rq->hrtick_timer; ++ ktime_t time = rq->hrtick_time; ++ ++ hrtimer_start(timer, time, HRTIMER_MODE_ABS_PINNED_HARD); ++} ++ ++/* ++ * called from hardirq (IPI) context ++ */ ++static void __hrtick_start(void *arg) ++{ ++ struct rq *rq = arg; ++ ++ raw_spin_lock(&rq->lock); ++ __hrtick_restart(rq); ++ raw_spin_unlock(&rq->lock); ++} ++ ++/* ++ * Called to set the hrtick timer state. ++ * ++ * called with rq->lock held and irqs disabled ++ */ ++void hrtick_start(struct rq *rq, u64 delay) ++{ ++ struct hrtimer *timer = &rq->hrtick_timer; ++ s64 delta; ++ ++ /* ++ * Don't schedule slices shorter than 10000ns, that just ++ * doesn't make sense and can cause timer DoS. ++ */ ++ delta = max_t(s64, delay, 10000LL); ++ ++ rq->hrtick_time = ktime_add_ns(timer->base->get_time(), delta); ++ ++ if (rq == this_rq()) ++ __hrtick_restart(rq); ++ else ++ smp_call_function_single_async(cpu_of(rq), &rq->hrtick_csd); ++} ++ ++#else ++/* ++ * Called to set the hrtick timer state. ++ * ++ * called with rq->lock held and irqs disabled ++ */ ++void hrtick_start(struct rq *rq, u64 delay) ++{ ++ /* ++ * Don't schedule slices shorter than 10000ns, that just ++ * doesn't make sense. Rely on vruntime for fairness. ++ */ ++ delay = max_t(u64, delay, 10000LL); ++ hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay), ++ HRTIMER_MODE_REL_PINNED_HARD); ++} ++#endif /* CONFIG_SMP */ ++ ++static void hrtick_rq_init(struct rq *rq) ++{ ++#ifdef CONFIG_SMP ++ INIT_CSD(&rq->hrtick_csd, __hrtick_start, rq); ++#endif ++ ++ hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); ++ rq->hrtick_timer.function = hrtick; ++} ++#else /* CONFIG_SCHED_HRTICK */ ++static inline int hrtick_enabled(struct rq *rq) ++{ ++ return 0; ++} ++ ++static inline void hrtick_clear(struct rq *rq) ++{ ++} ++ ++static inline void hrtick_rq_init(struct rq *rq) ++{ ++} ++#endif /* CONFIG_SCHED_HRTICK */ ++ ++static inline int __normal_prio(int policy, int rt_prio, int static_prio) ++{ ++ return rt_policy(policy) ? (MAX_RT_PRIO - 1 - rt_prio) : ++ static_prio + MAX_PRIORITY_ADJ; ++} ++ ++/* ++ * Calculate the expected normal priority: i.e. priority ++ * without taking RT-inheritance into account. Might be ++ * boosted by interactivity modifiers. Changes upon fork, ++ * setprio syscalls, and whenever the interactivity ++ * estimator recalculates. ++ */ ++static inline int normal_prio(struct task_struct *p) ++{ ++ return __normal_prio(p->policy, p->rt_priority, p->static_prio); ++} ++ ++/* ++ * Calculate the current priority, i.e. the priority ++ * taken into account by the scheduler. This value might ++ * be boosted by RT tasks as it will be RT if the task got ++ * RT-boosted. If not then it returns p->normal_prio. ++ */ ++static int effective_prio(struct task_struct *p) ++{ ++ p->normal_prio = normal_prio(p); ++ /* ++ * If we are RT tasks or we were boosted to RT priority, ++ * keep the priority unchanged. Otherwise, update priority ++ * to the normal priority: ++ */ ++ if (!rt_prio(p->prio)) ++ return p->normal_prio; ++ return p->prio; ++} ++ ++/* ++ * activate_task - move a task to the runqueue. ++ * ++ * Context: rq->lock ++ */ ++static void activate_task(struct task_struct *p, struct rq *rq) ++{ ++ enqueue_task(p, rq, ENQUEUE_WAKEUP); ++ p->on_rq = TASK_ON_RQ_QUEUED; ++ ++ /* ++ * If in_iowait is set, the code below may not trigger any cpufreq ++ * utilization updates, so do it here explicitly with the IOWAIT flag ++ * passed. ++ */ ++ cpufreq_update_util(rq, SCHED_CPUFREQ_IOWAIT * p->in_iowait); ++} ++ ++/* ++ * deactivate_task - remove a task from the runqueue. ++ * ++ * Context: rq->lock ++ */ ++static inline void deactivate_task(struct task_struct *p, struct rq *rq) ++{ ++ dequeue_task(p, rq, DEQUEUE_SLEEP); ++ p->on_rq = 0; ++ cpufreq_update_util(rq, 0); ++} ++ ++static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) ++{ ++#ifdef CONFIG_SMP ++ /* ++ * After ->cpu is set up to a new value, task_access_lock(p, ...) can be ++ * successfully executed on another CPU. We must ensure that updates of ++ * per-task data have been completed by this moment. ++ */ ++ smp_wmb(); ++ ++ WRITE_ONCE(task_thread_info(p)->cpu, cpu); ++#endif ++} ++ ++static inline bool is_migration_disabled(struct task_struct *p) ++{ ++#ifdef CONFIG_SMP ++ return p->migration_disabled; ++#else ++ return false; ++#endif ++} ++ ++#define SCA_CHECK 0x01 ++#define SCA_USER 0x08 ++ ++#ifdef CONFIG_SMP ++ ++void set_task_cpu(struct task_struct *p, unsigned int new_cpu) ++{ ++#ifdef CONFIG_SCHED_DEBUG ++ unsigned int state = READ_ONCE(p->__state); ++ ++ /* ++ * We should never call set_task_cpu() on a blocked task, ++ * ttwu() will sort out the placement. ++ */ ++ WARN_ON_ONCE(state != TASK_RUNNING && state != TASK_WAKING && !p->on_rq); ++ ++#ifdef CONFIG_LOCKDEP ++ /* ++ * The caller should hold either p->pi_lock or rq->lock, when changing ++ * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks. ++ * ++ * sched_move_task() holds both and thus holding either pins the cgroup, ++ * see task_group(). ++ */ ++ WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) || ++ lockdep_is_held(&task_rq(p)->lock))); ++#endif ++ /* ++ * Clearly, migrating tasks to offline CPUs is a fairly daft thing. ++ */ ++ WARN_ON_ONCE(!cpu_online(new_cpu)); ++ ++ WARN_ON_ONCE(is_migration_disabled(p)); ++#endif ++ trace_sched_migrate_task(p, new_cpu); ++ ++ if (task_cpu(p) != new_cpu) ++ { ++ rseq_migrate(p); ++ perf_event_task_migrate(p); ++ } ++ ++ __set_task_cpu(p, new_cpu); ++} ++ ++#define MDF_FORCE_ENABLED 0x80 ++ ++static void ++__do_set_cpus_ptr(struct task_struct *p, const struct cpumask *new_mask) ++{ ++ /* ++ * This here violates the locking rules for affinity, since we're only ++ * supposed to change these variables while holding both rq->lock and ++ * p->pi_lock. ++ * ++ * HOWEVER, it magically works, because ttwu() is the only code that ++ * accesses these variables under p->pi_lock and only does so after ++ * smp_cond_load_acquire(&p->on_cpu, !VAL), and we're in __schedule() ++ * before finish_task(). ++ * ++ * XXX do further audits, this smells like something putrid. ++ */ ++ SCHED_WARN_ON(!p->on_cpu); ++ p->cpus_ptr = new_mask; ++} ++ ++void migrate_disable(void) ++{ ++ struct task_struct *p = current; ++ int cpu; ++ ++ if (p->migration_disabled) { ++ p->migration_disabled++; ++ return; ++ } ++ ++ guard(preempt)(); ++ cpu = smp_processor_id(); ++ if (cpumask_test_cpu(cpu, &p->cpus_mask)) { ++ cpu_rq(cpu)->nr_pinned++; ++ p->migration_disabled = 1; ++ p->migration_flags &= ~MDF_FORCE_ENABLED; ++ ++ /* ++ * Violates locking rules! see comment in __do_set_cpus_ptr(). ++ */ ++ if (p->cpus_ptr == &p->cpus_mask) ++ __do_set_cpus_ptr(p, cpumask_of(cpu)); ++ } ++} ++EXPORT_SYMBOL_GPL(migrate_disable); ++ ++void migrate_enable(void) ++{ ++ struct task_struct *p = current; ++ ++ if (0 == p->migration_disabled) ++ return; ++ ++ if (p->migration_disabled > 1) { ++ p->migration_disabled--; ++ return; ++ } ++ ++ if (WARN_ON_ONCE(!p->migration_disabled)) ++ return; ++ ++ /* ++ * Ensure stop_task runs either before or after this, and that ++ * __set_cpus_allowed_ptr(SCA_MIGRATE_ENABLE) doesn't schedule(). ++ */ ++ guard(preempt)(); ++ /* ++ * Assumption: current should be running on allowed cpu ++ */ ++ WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(), &p->cpus_mask)); ++ if (p->cpus_ptr != &p->cpus_mask) ++ __do_set_cpus_ptr(p, &p->cpus_mask); ++ /* ++ * Mustn't clear migration_disabled() until cpus_ptr points back at the ++ * regular cpus_mask, otherwise things that race (eg. ++ * select_fallback_rq) get confused. ++ */ ++ barrier(); ++ p->migration_disabled = 0; ++ this_rq()->nr_pinned--; ++} ++EXPORT_SYMBOL_GPL(migrate_enable); ++ ++static inline bool rq_has_pinned_tasks(struct rq *rq) ++{ ++ return rq->nr_pinned; ++} ++ ++/* ++ * Per-CPU kthreads are allowed to run on !active && online CPUs, see ++ * __set_cpus_allowed_ptr() and select_fallback_rq(). ++ */ ++static inline bool is_cpu_allowed(struct task_struct *p, int cpu) ++{ ++ /* When not in the task's cpumask, no point in looking further. */ ++ if (!cpumask_test_cpu(cpu, p->cpus_ptr)) ++ return false; ++ ++ /* migrate_disabled() must be allowed to finish. */ ++ if (is_migration_disabled(p)) ++ return cpu_online(cpu); ++ ++ /* Non kernel threads are not allowed during either online or offline. */ ++ if (!(p->flags & PF_KTHREAD)) ++ return cpu_active(cpu) && task_cpu_possible(cpu, p); ++ ++ /* KTHREAD_IS_PER_CPU is always allowed. */ ++ if (kthread_is_per_cpu(p)) ++ return cpu_online(cpu); ++ ++ /* Regular kernel threads don't get to stay during offline. */ ++ if (cpu_dying(cpu)) ++ return false; ++ ++ /* But are allowed during online. */ ++ return cpu_online(cpu); ++} ++ ++/* ++ * This is how migration works: ++ * ++ * 1) we invoke migration_cpu_stop() on the target CPU using ++ * stop_one_cpu(). ++ * 2) stopper starts to run (implicitly forcing the migrated thread ++ * off the CPU) ++ * 3) it checks whether the migrated task is still in the wrong runqueue. ++ * 4) if it's in the wrong runqueue then the migration thread removes ++ * it and puts it into the right queue. ++ * 5) stopper completes and stop_one_cpu() returns and the migration ++ * is done. ++ */ ++ ++/* ++ * move_queued_task - move a queued task to new rq. ++ * ++ * Returns (locked) new rq. Old rq's lock is released. ++ */ ++static struct rq *move_queued_task(struct rq *rq, struct task_struct *p, int ++ new_cpu) ++{ ++ int src_cpu; ++ ++ lockdep_assert_held(&rq->lock); ++ ++ src_cpu = cpu_of(rq); ++ WRITE_ONCE(p->on_rq, TASK_ON_RQ_MIGRATING); ++ dequeue_task(p, rq, 0); ++ set_task_cpu(p, new_cpu); ++ raw_spin_unlock(&rq->lock); ++ ++ rq = cpu_rq(new_cpu); ++ ++ raw_spin_lock(&rq->lock); ++ WARN_ON_ONCE(task_cpu(p) != new_cpu); ++ ++ sched_mm_cid_migrate_to(rq, p, src_cpu); ++ ++ sched_task_sanity_check(p, rq); ++ enqueue_task(p, rq, 0); ++ p->on_rq = TASK_ON_RQ_QUEUED; ++ wakeup_preempt(rq); ++ ++ return rq; ++} ++ ++struct migration_arg { ++ struct task_struct *task; ++ int dest_cpu; ++}; ++ ++/* ++ * Move (not current) task off this CPU, onto the destination CPU. We're doing ++ * this because either it can't run here any more (set_cpus_allowed() ++ * away from this CPU, or CPU going down), or because we're ++ * attempting to rebalance this task on exec (sched_exec). ++ * ++ * So we race with normal scheduler movements, but that's OK, as long ++ * as the task is no longer on this CPU. ++ */ ++static struct rq *__migrate_task(struct rq *rq, struct task_struct *p, int ++ dest_cpu) ++{ ++ /* Affinity changed (again). */ ++ if (!is_cpu_allowed(p, dest_cpu)) ++ return rq; ++ ++ return move_queued_task(rq, p, dest_cpu); ++} ++ ++/* ++ * migration_cpu_stop - this will be executed by a highprio stopper thread ++ * and performs thread migration by bumping thread off CPU then ++ * 'pushing' onto another runqueue. ++ */ ++static int migration_cpu_stop(void *data) ++{ ++ struct migration_arg *arg = data; ++ struct task_struct *p = arg->task; ++ struct rq *rq = this_rq(); ++ unsigned long flags; ++ ++ /* ++ * The original target CPU might have gone down and we might ++ * be on another CPU but it doesn't matter. ++ */ ++ local_irq_save(flags); ++ /* ++ * We need to explicitly wake pending tasks before running ++ * __migrate_task() such that we will not miss enforcing cpus_ptr ++ * during wakeups, see set_cpus_allowed_ptr()'s TASK_WAKING test. ++ */ ++ flush_smp_call_function_queue(); ++ ++ raw_spin_lock(&p->pi_lock); ++ raw_spin_lock(&rq->lock); ++ /* ++ * If task_rq(p) != rq, it cannot be migrated here, because we're ++ * holding rq->lock, if p->on_rq == 0 it cannot get enqueued because ++ * we're holding p->pi_lock. ++ */ ++ if (task_rq(p) == rq && task_on_rq_queued(p)) { ++ update_rq_clock(rq); ++ rq = __migrate_task(rq, p, arg->dest_cpu); ++ } ++ raw_spin_unlock(&rq->lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); ++ ++ return 0; ++} ++ ++static inline void ++set_cpus_allowed_common(struct task_struct *p, struct affinity_context *ctx) ++{ ++ cpumask_copy(&p->cpus_mask, ctx->new_mask); ++ p->nr_cpus_allowed = cpumask_weight(ctx->new_mask); ++ ++ /* ++ * Swap in a new user_cpus_ptr if SCA_USER flag set ++ */ ++ if (ctx->flags & SCA_USER) ++ swap(p->user_cpus_ptr, ctx->user_mask); ++} ++ ++static void ++__do_set_cpus_allowed(struct task_struct *p, struct affinity_context *ctx) ++{ ++ lockdep_assert_held(&p->pi_lock); ++ set_cpus_allowed_common(p, ctx); ++} ++ ++/* ++ * Used for kthread_bind() and select_fallback_rq(), in both cases the user ++ * affinity (if any) should be destroyed too. ++ */ ++void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) ++{ ++ struct affinity_context ac = { ++ .new_mask = new_mask, ++ .user_mask = NULL, ++ .flags = SCA_USER, /* clear the user requested mask */ ++ }; ++ union cpumask_rcuhead { ++ cpumask_t cpumask; ++ struct rcu_head rcu; ++ }; ++ ++ __do_set_cpus_allowed(p, &ac); ++ ++ /* ++ * Because this is called with p->pi_lock held, it is not possible ++ * to use kfree() here (when PREEMPT_RT=y), therefore punt to using ++ * kfree_rcu(). ++ */ ++ kfree_rcu((union cpumask_rcuhead *)ac.user_mask, rcu); ++} ++ ++static cpumask_t *alloc_user_cpus_ptr(int node) ++{ ++ /* ++ * See do_set_cpus_allowed() above for the rcu_head usage. ++ */ ++ int size = max_t(int, cpumask_size(), sizeof(struct rcu_head)); ++ ++ return kmalloc_node(size, GFP_KERNEL, node); ++} ++ ++int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, ++ int node) ++{ ++ cpumask_t *user_mask; ++ unsigned long flags; ++ ++ /* ++ * Always clear dst->user_cpus_ptr first as their user_cpus_ptr's ++ * may differ by now due to racing. ++ */ ++ dst->user_cpus_ptr = NULL; ++ ++ /* ++ * This check is racy and losing the race is a valid situation. ++ * It is not worth the extra overhead of taking the pi_lock on ++ * every fork/clone. ++ */ ++ if (data_race(!src->user_cpus_ptr)) ++ return 0; ++ ++ user_mask = alloc_user_cpus_ptr(node); ++ if (!user_mask) ++ return -ENOMEM; ++ ++ /* ++ * Use pi_lock to protect content of user_cpus_ptr ++ * ++ * Though unlikely, user_cpus_ptr can be reset to NULL by a concurrent ++ * do_set_cpus_allowed(). ++ */ ++ raw_spin_lock_irqsave(&src->pi_lock, flags); ++ if (src->user_cpus_ptr) { ++ swap(dst->user_cpus_ptr, user_mask); ++ cpumask_copy(dst->user_cpus_ptr, src->user_cpus_ptr); ++ } ++ raw_spin_unlock_irqrestore(&src->pi_lock, flags); ++ ++ if (unlikely(user_mask)) ++ kfree(user_mask); ++ ++ return 0; ++} ++ ++static inline struct cpumask *clear_user_cpus_ptr(struct task_struct *p) ++{ ++ struct cpumask *user_mask = NULL; ++ ++ swap(p->user_cpus_ptr, user_mask); ++ ++ return user_mask; ++} ++ ++void release_user_cpus_ptr(struct task_struct *p) ++{ ++ kfree(clear_user_cpus_ptr(p)); ++} ++ ++#endif ++ ++/** ++ * task_curr - is this task currently executing on a CPU? ++ * @p: the task in question. ++ * ++ * Return: 1 if the task is currently executing. 0 otherwise. ++ */ ++inline int task_curr(const struct task_struct *p) ++{ ++ return cpu_curr(task_cpu(p)) == p; ++} ++ ++#ifdef CONFIG_SMP ++/*** ++ * kick_process - kick a running thread to enter/exit the kernel ++ * @p: the to-be-kicked thread ++ * ++ * Cause a process which is running on another CPU to enter ++ * kernel-mode, without any delay. (to get signals handled.) ++ * ++ * NOTE: this function doesn't have to take the runqueue lock, ++ * because all it wants to ensure is that the remote task enters ++ * the kernel. If the IPI races and the task has been migrated ++ * to another CPU then no harm is done and the purpose has been ++ * achieved as well. ++ */ ++void kick_process(struct task_struct *p) ++{ ++ guard(preempt)(); ++ int cpu = task_cpu(p); ++ ++ if ((cpu != smp_processor_id()) && task_curr(p)) ++ smp_send_reschedule(cpu); ++} ++EXPORT_SYMBOL_GPL(kick_process); ++ ++/* ++ * ->cpus_ptr is protected by both rq->lock and p->pi_lock ++ * ++ * A few notes on cpu_active vs cpu_online: ++ * ++ * - cpu_active must be a subset of cpu_online ++ * ++ * - on CPU-up we allow per-CPU kthreads on the online && !active CPU, ++ * see __set_cpus_allowed_ptr(). At this point the newly online ++ * CPU isn't yet part of the sched domains, and balancing will not ++ * see it. ++ * ++ * - on cpu-down we clear cpu_active() to mask the sched domains and ++ * avoid the load balancer to place new tasks on the to be removed ++ * CPU. Existing tasks will remain running there and will be taken ++ * off. ++ * ++ * This means that fallback selection must not select !active CPUs. ++ * And can assume that any active CPU must be online. Conversely ++ * select_task_rq() below may allow selection of !active CPUs in order ++ * to satisfy the above rules. ++ */ ++static int select_fallback_rq(int cpu, struct task_struct *p) ++{ ++ int nid = cpu_to_node(cpu); ++ const struct cpumask *nodemask = NULL; ++ enum { cpuset, possible, fail } state = cpuset; ++ int dest_cpu; ++ ++ /* ++ * If the node that the CPU is on has been offlined, cpu_to_node() ++ * will return -1. There is no CPU on the node, and we should ++ * select the CPU on the other node. ++ */ ++ if (nid != -1) { ++ nodemask = cpumask_of_node(nid); ++ ++ /* Look for allowed, online CPU in same node. */ ++ for_each_cpu(dest_cpu, nodemask) { ++ if (is_cpu_allowed(p, dest_cpu)) ++ return dest_cpu; ++ } ++ } ++ ++ for (;;) { ++ /* Any allowed, online CPU? */ ++ for_each_cpu(dest_cpu, p->cpus_ptr) { ++ if (!is_cpu_allowed(p, dest_cpu)) ++ continue; ++ goto out; ++ } ++ ++ /* No more Mr. Nice Guy. */ ++ switch (state) { ++ case cpuset: ++ if (cpuset_cpus_allowed_fallback(p)) { ++ state = possible; ++ break; ++ } ++ fallthrough; ++ case possible: ++ /* ++ * XXX When called from select_task_rq() we only ++ * hold p->pi_lock and again violate locking order. ++ * ++ * More yuck to audit. ++ */ ++ do_set_cpus_allowed(p, task_cpu_possible_mask(p)); ++ state = fail; ++ break; ++ ++ case fail: ++ BUG(); ++ break; ++ } ++ } ++ ++out: ++ if (state != cpuset) { ++ /* ++ * Don't tell them about moving exiting tasks or ++ * kernel threads (both mm NULL), since they never ++ * leave kernel. ++ */ ++ if (p->mm && printk_ratelimit()) { ++ printk_deferred("process %d (%s) no longer affine to cpu%d\n", ++ task_pid_nr(p), p->comm, cpu); ++ } ++ } ++ ++ return dest_cpu; ++} ++ ++static inline void ++sched_preempt_mask_flush(cpumask_t *mask, int prio) ++{ ++ int cpu; ++ ++ cpumask_copy(mask, sched_idle_mask); ++ ++ for_each_clear_bit(cpu, cpumask_bits(mask), nr_cpumask_bits) { ++ if (prio < cpu_rq(cpu)->prio) ++ cpumask_set_cpu(cpu, mask); ++ } ++} ++ ++static inline int ++preempt_mask_check(struct task_struct *p, cpumask_t *allow_mask, cpumask_t *preempt_mask) ++{ ++ int task_prio = task_sched_prio(p); ++ cpumask_t *mask = sched_preempt_mask + SCHED_QUEUE_BITS - 1 - task_prio; ++ int pr = atomic_read(&sched_prio_record); ++ ++ if (pr != task_prio) { ++ sched_preempt_mask_flush(mask, task_prio); ++ atomic_set(&sched_prio_record, task_prio); ++ } ++ ++ return cpumask_and(preempt_mask, allow_mask, mask); ++} ++ ++static inline int select_task_rq(struct task_struct *p) ++{ ++ cpumask_t allow_mask, mask; ++ ++ if (unlikely(!cpumask_and(&allow_mask, p->cpus_ptr, cpu_active_mask))) ++ return select_fallback_rq(task_cpu(p), p); ++ ++ if ( ++#ifdef CONFIG_SCHED_SMT ++ cpumask_and(&mask, &allow_mask, &sched_sg_idle_mask) || ++#endif ++ cpumask_and(&mask, &allow_mask, sched_idle_mask) || ++ preempt_mask_check(p, &allow_mask, &mask)) ++ return best_mask_cpu(task_cpu(p), &mask); ++ ++ return best_mask_cpu(task_cpu(p), &allow_mask); ++} ++ ++void sched_set_stop_task(int cpu, struct task_struct *stop) ++{ ++ static struct lock_class_key stop_pi_lock; ++ struct sched_param stop_param = { .sched_priority = STOP_PRIO }; ++ struct sched_param start_param = { .sched_priority = 0 }; ++ struct task_struct *old_stop = cpu_rq(cpu)->stop; ++ ++ if (stop) { ++ /* ++ * Make it appear like a SCHED_FIFO task, its something ++ * userspace knows about and won't get confused about. ++ * ++ * Also, it will make PI more or less work without too ++ * much confusion -- but then, stop work should not ++ * rely on PI working anyway. ++ */ ++ sched_setscheduler_nocheck(stop, SCHED_FIFO, &stop_param); ++ ++ /* ++ * The PI code calls rt_mutex_setprio() with ->pi_lock held to ++ * adjust the effective priority of a task. As a result, ++ * rt_mutex_setprio() can trigger (RT) balancing operations, ++ * which can then trigger wakeups of the stop thread to push ++ * around the current task. ++ * ++ * The stop task itself will never be part of the PI-chain, it ++ * never blocks, therefore that ->pi_lock recursion is safe. ++ * Tell lockdep about this by placing the stop->pi_lock in its ++ * own class. ++ */ ++ lockdep_set_class(&stop->pi_lock, &stop_pi_lock); ++ } ++ ++ cpu_rq(cpu)->stop = stop; ++ ++ if (old_stop) { ++ /* ++ * Reset it back to a normal scheduling policy so that ++ * it can die in pieces. ++ */ ++ sched_setscheduler_nocheck(old_stop, SCHED_NORMAL, &start_param); ++ } ++} ++ ++static int affine_move_task(struct rq *rq, struct task_struct *p, int dest_cpu, ++ raw_spinlock_t *lock, unsigned long irq_flags) ++ __releases(rq->lock) ++ __releases(p->pi_lock) ++{ ++ /* Can the task run on the task's current CPU? If so, we're done */ ++ if (!cpumask_test_cpu(task_cpu(p), &p->cpus_mask)) { ++ if (p->migration_disabled) { ++ if (likely(p->cpus_ptr != &p->cpus_mask)) ++ __do_set_cpus_ptr(p, &p->cpus_mask); ++ p->migration_disabled = 0; ++ p->migration_flags |= MDF_FORCE_ENABLED; ++ /* When p is migrate_disabled, rq->lock should be held */ ++ rq->nr_pinned--; ++ } ++ ++ if (task_on_cpu(p) || READ_ONCE(p->__state) == TASK_WAKING) { ++ struct migration_arg arg = { p, dest_cpu }; ++ ++ /* Need help from migration thread: drop lock and wait. */ ++ __task_access_unlock(p, lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, irq_flags); ++ stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); ++ return 0; ++ } ++ if (task_on_rq_queued(p)) { ++ /* ++ * OK, since we're going to drop the lock immediately ++ * afterwards anyway. ++ */ ++ update_rq_clock(rq); ++ rq = move_queued_task(rq, p, dest_cpu); ++ lock = &rq->lock; ++ } ++ } ++ __task_access_unlock(p, lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, irq_flags); ++ return 0; ++} ++ ++static int __set_cpus_allowed_ptr_locked(struct task_struct *p, ++ struct affinity_context *ctx, ++ struct rq *rq, ++ raw_spinlock_t *lock, ++ unsigned long irq_flags) ++{ ++ const struct cpumask *cpu_allowed_mask = task_cpu_possible_mask(p); ++ const struct cpumask *cpu_valid_mask = cpu_active_mask; ++ bool kthread = p->flags & PF_KTHREAD; ++ int dest_cpu; ++ int ret = 0; ++ ++ if (kthread || is_migration_disabled(p)) { ++ /* ++ * Kernel threads are allowed on online && !active CPUs, ++ * however, during cpu-hot-unplug, even these might get pushed ++ * away if not KTHREAD_IS_PER_CPU. ++ * ++ * Specifically, migration_disabled() tasks must not fail the ++ * cpumask_any_and_distribute() pick below, esp. so on ++ * SCA_MIGRATE_ENABLE, otherwise we'll not call ++ * set_cpus_allowed_common() and actually reset p->cpus_ptr. ++ */ ++ cpu_valid_mask = cpu_online_mask; ++ } ++ ++ if (!kthread && !cpumask_subset(ctx->new_mask, cpu_allowed_mask)) { ++ ret = -EINVAL; ++ goto out; ++ } ++ ++ /* ++ * Must re-check here, to close a race against __kthread_bind(), ++ * sched_setaffinity() is not guaranteed to observe the flag. ++ */ ++ if ((ctx->flags & SCA_CHECK) && (p->flags & PF_NO_SETAFFINITY)) { ++ ret = -EINVAL; ++ goto out; ++ } ++ ++ if (cpumask_equal(&p->cpus_mask, ctx->new_mask)) ++ goto out; ++ ++ dest_cpu = cpumask_any_and(cpu_valid_mask, ctx->new_mask); ++ if (dest_cpu >= nr_cpu_ids) { ++ ret = -EINVAL; ++ goto out; ++ } ++ ++ __do_set_cpus_allowed(p, ctx); ++ ++ return affine_move_task(rq, p, dest_cpu, lock, irq_flags); ++ ++out: ++ __task_access_unlock(p, lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, irq_flags); ++ ++ return ret; ++} ++ ++/* ++ * Change a given task's CPU affinity. Migrate the thread to a ++ * is removed from the allowed bitmask. ++ * ++ * NOTE: the caller must have a valid reference to the task, the ++ * task must not exit() & deallocate itself prematurely. The ++ * call is not atomic; no spinlocks may be held. ++ */ ++static int __set_cpus_allowed_ptr(struct task_struct *p, ++ struct affinity_context *ctx) ++{ ++ unsigned long irq_flags; ++ struct rq *rq; ++ raw_spinlock_t *lock; ++ ++ raw_spin_lock_irqsave(&p->pi_lock, irq_flags); ++ rq = __task_access_lock(p, &lock); ++ /* ++ * Masking should be skipped if SCA_USER or any of the SCA_MIGRATE_* ++ * flags are set. ++ */ ++ if (p->user_cpus_ptr && ++ !(ctx->flags & SCA_USER) && ++ cpumask_and(rq->scratch_mask, ctx->new_mask, p->user_cpus_ptr)) ++ ctx->new_mask = rq->scratch_mask; ++ ++ ++ return __set_cpus_allowed_ptr_locked(p, ctx, rq, lock, irq_flags); ++} ++ ++int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) ++{ ++ struct affinity_context ac = { ++ .new_mask = new_mask, ++ .flags = 0, ++ }; ++ ++ return __set_cpus_allowed_ptr(p, &ac); ++} ++EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); ++ ++/* ++ * Change a given task's CPU affinity to the intersection of its current ++ * affinity mask and @subset_mask, writing the resulting mask to @new_mask. ++ * If user_cpus_ptr is defined, use it as the basis for restricting CPU ++ * affinity or use cpu_online_mask instead. ++ * ++ * If the resulting mask is empty, leave the affinity unchanged and return ++ * -EINVAL. ++ */ ++static int restrict_cpus_allowed_ptr(struct task_struct *p, ++ struct cpumask *new_mask, ++ const struct cpumask *subset_mask) ++{ ++ struct affinity_context ac = { ++ .new_mask = new_mask, ++ .flags = 0, ++ }; ++ unsigned long irq_flags; ++ raw_spinlock_t *lock; ++ struct rq *rq; ++ int err; ++ ++ raw_spin_lock_irqsave(&p->pi_lock, irq_flags); ++ rq = __task_access_lock(p, &lock); ++ ++ if (!cpumask_and(new_mask, task_user_cpus(p), subset_mask)) { ++ err = -EINVAL; ++ goto err_unlock; ++ } ++ ++ return __set_cpus_allowed_ptr_locked(p, &ac, rq, lock, irq_flags); ++ ++err_unlock: ++ __task_access_unlock(p, lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, irq_flags); ++ return err; ++} ++ ++/* ++ * Restrict the CPU affinity of task @p so that it is a subset of ++ * task_cpu_possible_mask() and point @p->user_cpus_ptr to a copy of the ++ * old affinity mask. If the resulting mask is empty, we warn and walk ++ * up the cpuset hierarchy until we find a suitable mask. ++ */ ++void force_compatible_cpus_allowed_ptr(struct task_struct *p) ++{ ++ cpumask_var_t new_mask; ++ const struct cpumask *override_mask = task_cpu_possible_mask(p); ++ ++ alloc_cpumask_var(&new_mask, GFP_KERNEL); ++ ++ /* ++ * __migrate_task() can fail silently in the face of concurrent ++ * offlining of the chosen destination CPU, so take the hotplug ++ * lock to ensure that the migration succeeds. ++ */ ++ cpus_read_lock(); ++ if (!cpumask_available(new_mask)) ++ goto out_set_mask; ++ ++ if (!restrict_cpus_allowed_ptr(p, new_mask, override_mask)) ++ goto out_free_mask; ++ ++ /* ++ * We failed to find a valid subset of the affinity mask for the ++ * task, so override it based on its cpuset hierarchy. ++ */ ++ cpuset_cpus_allowed(p, new_mask); ++ override_mask = new_mask; ++ ++out_set_mask: ++ if (printk_ratelimit()) { ++ printk_deferred("Overriding affinity for process %d (%s) to CPUs %*pbl\n", ++ task_pid_nr(p), p->comm, ++ cpumask_pr_args(override_mask)); ++ } ++ ++ WARN_ON(set_cpus_allowed_ptr(p, override_mask)); ++out_free_mask: ++ cpus_read_unlock(); ++ free_cpumask_var(new_mask); ++} ++ ++static int ++__sched_setaffinity(struct task_struct *p, struct affinity_context *ctx); ++ ++/* ++ * Restore the affinity of a task @p which was previously restricted by a ++ * call to force_compatible_cpus_allowed_ptr(). ++ * ++ * It is the caller's responsibility to serialise this with any calls to ++ * force_compatible_cpus_allowed_ptr(@p). ++ */ ++void relax_compatible_cpus_allowed_ptr(struct task_struct *p) ++{ ++ struct affinity_context ac = { ++ .new_mask = task_user_cpus(p), ++ .flags = 0, ++ }; ++ int ret; ++ ++ /* ++ * Try to restore the old affinity mask with __sched_setaffinity(). ++ * Cpuset masking will be done there too. ++ */ ++ ret = __sched_setaffinity(p, &ac); ++ WARN_ON_ONCE(ret); ++} ++ ++#else /* CONFIG_SMP */ ++ ++static inline int select_task_rq(struct task_struct *p) ++{ ++ return 0; ++} ++ ++static inline int ++__set_cpus_allowed_ptr(struct task_struct *p, ++ struct affinity_context *ctx) ++{ ++ return set_cpus_allowed_ptr(p, ctx->new_mask); ++} ++ ++static inline bool rq_has_pinned_tasks(struct rq *rq) ++{ ++ return false; ++} ++ ++static inline cpumask_t *alloc_user_cpus_ptr(int node) ++{ ++ return NULL; ++} ++ ++#endif /* !CONFIG_SMP */ ++ ++static void ++ttwu_stat(struct task_struct *p, int cpu, int wake_flags) ++{ ++ struct rq *rq; ++ ++ if (!schedstat_enabled()) ++ return; ++ ++ rq = this_rq(); ++ ++#ifdef CONFIG_SMP ++ if (cpu == rq->cpu) { ++ __schedstat_inc(rq->ttwu_local); ++ __schedstat_inc(p->stats.nr_wakeups_local); ++ } else { ++ /** Alt schedule FW ToDo: ++ * How to do ttwu_wake_remote ++ */ ++ } ++#endif /* CONFIG_SMP */ ++ ++ __schedstat_inc(rq->ttwu_count); ++ __schedstat_inc(p->stats.nr_wakeups); ++} ++ ++/* ++ * Mark the task runnable. ++ */ ++static inline void ttwu_do_wakeup(struct task_struct *p) ++{ ++ WRITE_ONCE(p->__state, TASK_RUNNING); ++ trace_sched_wakeup(p); ++} ++ ++static inline void ++ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags) ++{ ++ if (p->sched_contributes_to_load) ++ rq->nr_uninterruptible--; ++ ++ if ( ++#ifdef CONFIG_SMP ++ !(wake_flags & WF_MIGRATED) && ++#endif ++ p->in_iowait) { ++ delayacct_blkio_end(p); ++ atomic_dec(&task_rq(p)->nr_iowait); ++ } ++ ++ activate_task(p, rq); ++ wakeup_preempt(rq); ++ ++ ttwu_do_wakeup(p); ++} ++ ++/* ++ * Consider @p being inside a wait loop: ++ * ++ * for (;;) { ++ * set_current_state(TASK_UNINTERRUPTIBLE); ++ * ++ * if (CONDITION) ++ * break; ++ * ++ * schedule(); ++ * } ++ * __set_current_state(TASK_RUNNING); ++ * ++ * between set_current_state() and schedule(). In this case @p is still ++ * runnable, so all that needs doing is change p->state back to TASK_RUNNING in ++ * an atomic manner. ++ * ++ * By taking task_rq(p)->lock we serialize against schedule(), if @p->on_rq ++ * then schedule() must still happen and p->state can be changed to ++ * TASK_RUNNING. Otherwise we lost the race, schedule() has happened, and we ++ * need to do a full wakeup with enqueue. ++ * ++ * Returns: %true when the wakeup is done, ++ * %false otherwise. ++ */ ++static int ttwu_runnable(struct task_struct *p, int wake_flags) ++{ ++ struct rq *rq; ++ raw_spinlock_t *lock; ++ int ret = 0; ++ ++ rq = __task_access_lock(p, &lock); ++ if (task_on_rq_queued(p)) { ++ if (!task_on_cpu(p)) { ++ /* ++ * When on_rq && !on_cpu the task is preempted, see if ++ * it should preempt the task that is current now. ++ */ ++ update_rq_clock(rq); ++ wakeup_preempt(rq); ++ } ++ ttwu_do_wakeup(p); ++ ret = 1; ++ } ++ __task_access_unlock(p, lock); ++ ++ return ret; ++} ++ ++#ifdef CONFIG_SMP ++void sched_ttwu_pending(void *arg) ++{ ++ struct llist_node *llist = arg; ++ struct rq *rq = this_rq(); ++ struct task_struct *p, *t; ++ struct rq_flags rf; ++ ++ if (!llist) ++ return; ++ ++ rq_lock_irqsave(rq, &rf); ++ update_rq_clock(rq); ++ ++ llist_for_each_entry_safe(p, t, llist, wake_entry.llist) { ++ if (WARN_ON_ONCE(p->on_cpu)) ++ smp_cond_load_acquire(&p->on_cpu, !VAL); ++ ++ if (WARN_ON_ONCE(task_cpu(p) != cpu_of(rq))) ++ set_task_cpu(p, cpu_of(rq)); ++ ++ ttwu_do_activate(rq, p, p->sched_remote_wakeup ? WF_MIGRATED : 0); ++ } ++ ++ /* ++ * Must be after enqueueing at least once task such that ++ * idle_cpu() does not observe a false-negative -- if it does, ++ * it is possible for select_idle_siblings() to stack a number ++ * of tasks on this CPU during that window. ++ * ++ * It is ok to clear ttwu_pending when another task pending. ++ * We will receive IPI after local irq enabled and then enqueue it. ++ * Since now nr_running > 0, idle_cpu() will always get correct result. ++ */ ++ WRITE_ONCE(rq->ttwu_pending, 0); ++ rq_unlock_irqrestore(rq, &rf); ++} ++ ++/* ++ * Prepare the scene for sending an IPI for a remote smp_call ++ * ++ * Returns true if the caller can proceed with sending the IPI. ++ * Returns false otherwise. ++ */ ++bool call_function_single_prep_ipi(int cpu) ++{ ++ if (set_nr_if_polling(cpu_rq(cpu)->idle)) { ++ trace_sched_wake_idle_without_ipi(cpu); ++ return false; ++ } ++ ++ return true; ++} ++ ++/* ++ * Queue a task on the target CPUs wake_list and wake the CPU via IPI if ++ * necessary. The wakee CPU on receipt of the IPI will queue the task ++ * via sched_ttwu_wakeup() for activation so the wakee incurs the cost ++ * of the wakeup instead of the waker. ++ */ ++static void __ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ ++ p->sched_remote_wakeup = !!(wake_flags & WF_MIGRATED); ++ ++ WRITE_ONCE(rq->ttwu_pending, 1); ++ __smp_call_single_queue(cpu, &p->wake_entry.llist); ++} ++ ++static inline bool ttwu_queue_cond(struct task_struct *p, int cpu) ++{ ++ /* ++ * Do not complicate things with the async wake_list while the CPU is ++ * in hotplug state. ++ */ ++ if (!cpu_active(cpu)) ++ return false; ++ ++ /* Ensure the task will still be allowed to run on the CPU. */ ++ if (!cpumask_test_cpu(cpu, p->cpus_ptr)) ++ return false; ++ ++ /* ++ * If the CPU does not share cache, then queue the task on the ++ * remote rqs wakelist to avoid accessing remote data. ++ */ ++ if (!cpus_share_cache(smp_processor_id(), cpu)) ++ return true; ++ ++ if (cpu == smp_processor_id()) ++ return false; ++ ++ /* ++ * If the wakee cpu is idle, or the task is descheduling and the ++ * only running task on the CPU, then use the wakelist to offload ++ * the task activation to the idle (or soon-to-be-idle) CPU as ++ * the current CPU is likely busy. nr_running is checked to ++ * avoid unnecessary task stacking. ++ * ++ * Note that we can only get here with (wakee) p->on_rq=0, ++ * p->on_cpu can be whatever, we've done the dequeue, so ++ * the wakee has been accounted out of ->nr_running. ++ */ ++ if (!cpu_rq(cpu)->nr_running) ++ return true; ++ ++ return false; ++} ++ ++static bool ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags) ++{ ++ if (__is_defined(ALT_SCHED_TTWU_QUEUE) && ttwu_queue_cond(p, cpu)) { ++ sched_clock_cpu(cpu); /* Sync clocks across CPUs */ ++ __ttwu_queue_wakelist(p, cpu, wake_flags); ++ return true; ++ } ++ ++ return false; ++} ++ ++void wake_up_if_idle(int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ ++ guard(rcu)(); ++ if (is_idle_task(rcu_dereference(rq->curr))) { ++ guard(raw_spinlock_irqsave)(&rq->lock); ++ if (is_idle_task(rq->curr)) ++ resched_curr(rq); ++ } ++} ++ ++bool cpus_share_cache(int this_cpu, int that_cpu) ++{ ++ if (this_cpu == that_cpu) ++ return true; ++ ++ return per_cpu(sd_llc_id, this_cpu) == per_cpu(sd_llc_id, that_cpu); ++} ++#else /* !CONFIG_SMP */ ++ ++static inline bool ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags) ++{ ++ return false; ++} ++ ++#endif /* CONFIG_SMP */ ++ ++static inline void ttwu_queue(struct task_struct *p, int cpu, int wake_flags) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ ++ if (ttwu_queue_wakelist(p, cpu, wake_flags)) ++ return; ++ ++ raw_spin_lock(&rq->lock); ++ update_rq_clock(rq); ++ ttwu_do_activate(rq, p, wake_flags); ++ raw_spin_unlock(&rq->lock); ++} ++ ++/* ++ * Invoked from try_to_wake_up() to check whether the task can be woken up. ++ * ++ * The caller holds p::pi_lock if p != current or has preemption ++ * disabled when p == current. ++ * ++ * The rules of saved_state: ++ * ++ * The related locking code always holds p::pi_lock when updating ++ * p::saved_state, which means the code is fully serialized in both cases. ++ * ++ * For PREEMPT_RT, the lock wait and lock wakeups happen via TASK_RTLOCK_WAIT. ++ * No other bits set. This allows to distinguish all wakeup scenarios. ++ * ++ * For FREEZER, the wakeup happens via TASK_FROZEN. No other bits set. This ++ * allows us to prevent early wakeup of tasks before they can be run on ++ * asymmetric ISA architectures (eg ARMv9). ++ */ ++static __always_inline ++bool ttwu_state_match(struct task_struct *p, unsigned int state, int *success) ++{ ++ int match; ++ ++ if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) { ++ WARN_ON_ONCE((state & TASK_RTLOCK_WAIT) && ++ state != TASK_RTLOCK_WAIT); ++ } ++ ++ *success = !!(match = __task_state_match(p, state)); ++ ++ /* ++ * Saved state preserves the task state across blocking on ++ * an RT lock or TASK_FREEZABLE tasks. If the state matches, ++ * set p::saved_state to TASK_RUNNING, but do not wake the task ++ * because it waits for a lock wakeup or __thaw_task(). Also ++ * indicate success because from the regular waker's point of ++ * view this has succeeded. ++ * ++ * After acquiring the lock the task will restore p::__state ++ * from p::saved_state which ensures that the regular ++ * wakeup is not lost. The restore will also set ++ * p::saved_state to TASK_RUNNING so any further tests will ++ * not result in false positives vs. @success ++ */ ++ if (match < 0) ++ p->saved_state = TASK_RUNNING; ++ ++ return match > 0; ++} ++ ++/* ++ * Notes on Program-Order guarantees on SMP systems. ++ * ++ * MIGRATION ++ * ++ * The basic program-order guarantee on SMP systems is that when a task [t] ++ * migrates, all its activity on its old CPU [c0] happens-before any subsequent ++ * execution on its new CPU [c1]. ++ * ++ * For migration (of runnable tasks) this is provided by the following means: ++ * ++ * A) UNLOCK of the rq(c0)->lock scheduling out task t ++ * B) migration for t is required to synchronize *both* rq(c0)->lock and ++ * rq(c1)->lock (if not at the same time, then in that order). ++ * C) LOCK of the rq(c1)->lock scheduling in task ++ * ++ * Transitivity guarantees that B happens after A and C after B. ++ * Note: we only require RCpc transitivity. ++ * Note: the CPU doing B need not be c0 or c1 ++ * ++ * Example: ++ * ++ * CPU0 CPU1 CPU2 ++ * ++ * LOCK rq(0)->lock ++ * sched-out X ++ * sched-in Y ++ * UNLOCK rq(0)->lock ++ * ++ * LOCK rq(0)->lock // orders against CPU0 ++ * dequeue X ++ * UNLOCK rq(0)->lock ++ * ++ * LOCK rq(1)->lock ++ * enqueue X ++ * UNLOCK rq(1)->lock ++ * ++ * LOCK rq(1)->lock // orders against CPU2 ++ * sched-out Z ++ * sched-in X ++ * UNLOCK rq(1)->lock ++ * ++ * ++ * BLOCKING -- aka. SLEEP + WAKEUP ++ * ++ * For blocking we (obviously) need to provide the same guarantee as for ++ * migration. However the means are completely different as there is no lock ++ * chain to provide order. Instead we do: ++ * ++ * 1) smp_store_release(X->on_cpu, 0) -- finish_task() ++ * 2) smp_cond_load_acquire(!X->on_cpu) -- try_to_wake_up() ++ * ++ * Example: ++ * ++ * CPU0 (schedule) CPU1 (try_to_wake_up) CPU2 (schedule) ++ * ++ * LOCK rq(0)->lock LOCK X->pi_lock ++ * dequeue X ++ * sched-out X ++ * smp_store_release(X->on_cpu, 0); ++ * ++ * smp_cond_load_acquire(&X->on_cpu, !VAL); ++ * X->state = WAKING ++ * set_task_cpu(X,2) ++ * ++ * LOCK rq(2)->lock ++ * enqueue X ++ * X->state = RUNNING ++ * UNLOCK rq(2)->lock ++ * ++ * LOCK rq(2)->lock // orders against CPU1 ++ * sched-out Z ++ * sched-in X ++ * UNLOCK rq(2)->lock ++ * ++ * UNLOCK X->pi_lock ++ * UNLOCK rq(0)->lock ++ * ++ * ++ * However; for wakeups there is a second guarantee we must provide, namely we ++ * must observe the state that lead to our wakeup. That is, not only must our ++ * task observe its own prior state, it must also observe the stores prior to ++ * its wakeup. ++ * ++ * This means that any means of doing remote wakeups must order the CPU doing ++ * the wakeup against the CPU the task is going to end up running on. This, ++ * however, is already required for the regular Program-Order guarantee above, ++ * since the waking CPU is the one issueing the ACQUIRE (smp_cond_load_acquire). ++ * ++ */ ++ ++/** ++ * try_to_wake_up - wake up a thread ++ * @p: the thread to be awakened ++ * @state: the mask of task states that can be woken ++ * @wake_flags: wake modifier flags (WF_*) ++ * ++ * Conceptually does: ++ * ++ * If (@state & @p->state) @p->state = TASK_RUNNING. ++ * ++ * If the task was not queued/runnable, also place it back on a runqueue. ++ * ++ * This function is atomic against schedule() which would dequeue the task. ++ * ++ * It issues a full memory barrier before accessing @p->state, see the comment ++ * with set_current_state(). ++ * ++ * Uses p->pi_lock to serialize against concurrent wake-ups. ++ * ++ * Relies on p->pi_lock stabilizing: ++ * - p->sched_class ++ * - p->cpus_ptr ++ * - p->sched_task_group ++ * in order to do migration, see its use of select_task_rq()/set_task_cpu(). ++ * ++ * Tries really hard to only take one task_rq(p)->lock for performance. ++ * Takes rq->lock in: ++ * - ttwu_runnable() -- old rq, unavoidable, see comment there; ++ * - ttwu_queue() -- new rq, for enqueue of the task; ++ * - psi_ttwu_dequeue() -- much sadness :-( accounting will kill us. ++ * ++ * As a consequence we race really badly with just about everything. See the ++ * many memory barriers and their comments for details. ++ * ++ * Return: %true if @p->state changes (an actual wakeup was done), ++ * %false otherwise. ++ */ ++int try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) ++{ ++ guard(preempt)(); ++ int cpu, success = 0; ++ ++ if (p == current) { ++ /* ++ * We're waking current, this means 'p->on_rq' and 'task_cpu(p) ++ * == smp_processor_id()'. Together this means we can special ++ * case the whole 'p->on_rq && ttwu_runnable()' case below ++ * without taking any locks. ++ * ++ * In particular: ++ * - we rely on Program-Order guarantees for all the ordering, ++ * - we're serialized against set_special_state() by virtue of ++ * it disabling IRQs (this allows not taking ->pi_lock). ++ */ ++ if (!ttwu_state_match(p, state, &success)) ++ goto out; ++ ++ trace_sched_waking(p); ++ ttwu_do_wakeup(p); ++ goto out; ++ } ++ ++ /* ++ * If we are going to wake up a thread waiting for CONDITION we ++ * need to ensure that CONDITION=1 done by the caller can not be ++ * reordered with p->state check below. This pairs with smp_store_mb() ++ * in set_current_state() that the waiting thread does. ++ */ ++ scoped_guard (raw_spinlock_irqsave, &p->pi_lock) { ++ smp_mb__after_spinlock(); ++ if (!ttwu_state_match(p, state, &success)) ++ break; ++ ++ trace_sched_waking(p); ++ ++ /* ++ * Ensure we load p->on_rq _after_ p->state, otherwise it would ++ * be possible to, falsely, observe p->on_rq == 0 and get stuck ++ * in smp_cond_load_acquire() below. ++ * ++ * sched_ttwu_pending() try_to_wake_up() ++ * STORE p->on_rq = 1 LOAD p->state ++ * UNLOCK rq->lock ++ * ++ * __schedule() (switch to task 'p') ++ * LOCK rq->lock smp_rmb(); ++ * smp_mb__after_spinlock(); ++ * UNLOCK rq->lock ++ * ++ * [task p] ++ * STORE p->state = UNINTERRUPTIBLE LOAD p->on_rq ++ * ++ * Pairs with the LOCK+smp_mb__after_spinlock() on rq->lock in ++ * __schedule(). See the comment for smp_mb__after_spinlock(). ++ * ++ * A similar smp_rmb() lives in __task_needs_rq_lock(). ++ */ ++ smp_rmb(); ++ if (READ_ONCE(p->on_rq) && ttwu_runnable(p, wake_flags)) ++ break; ++ ++#ifdef CONFIG_SMP ++ /* ++ * Ensure we load p->on_cpu _after_ p->on_rq, otherwise it would be ++ * possible to, falsely, observe p->on_cpu == 0. ++ * ++ * One must be running (->on_cpu == 1) in order to remove oneself ++ * from the runqueue. ++ * ++ * __schedule() (switch to task 'p') try_to_wake_up() ++ * STORE p->on_cpu = 1 LOAD p->on_rq ++ * UNLOCK rq->lock ++ * ++ * __schedule() (put 'p' to sleep) ++ * LOCK rq->lock smp_rmb(); ++ * smp_mb__after_spinlock(); ++ * STORE p->on_rq = 0 LOAD p->on_cpu ++ * ++ * Pairs with the LOCK+smp_mb__after_spinlock() on rq->lock in ++ * __schedule(). See the comment for smp_mb__after_spinlock(). ++ * ++ * Form a control-dep-acquire with p->on_rq == 0 above, to ensure ++ * schedule()'s deactivate_task() has 'happened' and p will no longer ++ * care about it's own p->state. See the comment in __schedule(). ++ */ ++ smp_acquire__after_ctrl_dep(); ++ ++ /* ++ * We're doing the wakeup (@success == 1), they did a dequeue (p->on_rq ++ * == 0), which means we need to do an enqueue, change p->state to ++ * TASK_WAKING such that we can unlock p->pi_lock before doing the ++ * enqueue, such as ttwu_queue_wakelist(). ++ */ ++ WRITE_ONCE(p->__state, TASK_WAKING); ++ ++ /* ++ * If the owning (remote) CPU is still in the middle of schedule() with ++ * this task as prev, considering queueing p on the remote CPUs wake_list ++ * which potentially sends an IPI instead of spinning on p->on_cpu to ++ * let the waker make forward progress. This is safe because IRQs are ++ * disabled and the IPI will deliver after on_cpu is cleared. ++ * ++ * Ensure we load task_cpu(p) after p->on_cpu: ++ * ++ * set_task_cpu(p, cpu); ++ * STORE p->cpu = @cpu ++ * __schedule() (switch to task 'p') ++ * LOCK rq->lock ++ * smp_mb__after_spin_lock() smp_cond_load_acquire(&p->on_cpu) ++ * STORE p->on_cpu = 1 LOAD p->cpu ++ * ++ * to ensure we observe the correct CPU on which the task is currently ++ * scheduling. ++ */ ++ if (smp_load_acquire(&p->on_cpu) && ++ ttwu_queue_wakelist(p, task_cpu(p), wake_flags)) ++ break; ++ ++ /* ++ * If the owning (remote) CPU is still in the middle of schedule() with ++ * this task as prev, wait until it's done referencing the task. ++ * ++ * Pairs with the smp_store_release() in finish_task(). ++ * ++ * This ensures that tasks getting woken will be fully ordered against ++ * their previous state and preserve Program Order. ++ */ ++ smp_cond_load_acquire(&p->on_cpu, !VAL); ++ ++ sched_task_ttwu(p); ++ ++ if ((wake_flags & WF_CURRENT_CPU) && ++ cpumask_test_cpu(smp_processor_id(), p->cpus_ptr)) ++ cpu = smp_processor_id(); ++ else ++ cpu = select_task_rq(p); ++ ++ if (cpu != task_cpu(p)) { ++ if (p->in_iowait) { ++ delayacct_blkio_end(p); ++ atomic_dec(&task_rq(p)->nr_iowait); ++ } ++ ++ wake_flags |= WF_MIGRATED; ++ set_task_cpu(p, cpu); ++ } ++#else ++ sched_task_ttwu(p); ++ ++ cpu = task_cpu(p); ++#endif /* CONFIG_SMP */ ++ ++ ttwu_queue(p, cpu, wake_flags); ++ } ++out: ++ if (success) ++ ttwu_stat(p, task_cpu(p), wake_flags); ++ ++ return success; ++} ++ ++static bool __task_needs_rq_lock(struct task_struct *p) ++{ ++ unsigned int state = READ_ONCE(p->__state); ++ ++ /* ++ * Since pi->lock blocks try_to_wake_up(), we don't need rq->lock when ++ * the task is blocked. Make sure to check @state since ttwu() can drop ++ * locks at the end, see ttwu_queue_wakelist(). ++ */ ++ if (state == TASK_RUNNING || state == TASK_WAKING) ++ return true; ++ ++ /* ++ * Ensure we load p->on_rq after p->__state, otherwise it would be ++ * possible to, falsely, observe p->on_rq == 0. ++ * ++ * See try_to_wake_up() for a longer comment. ++ */ ++ smp_rmb(); ++ if (p->on_rq) ++ return true; ++ ++#ifdef CONFIG_SMP ++ /* ++ * Ensure the task has finished __schedule() and will not be referenced ++ * anymore. Again, see try_to_wake_up() for a longer comment. ++ */ ++ smp_rmb(); ++ smp_cond_load_acquire(&p->on_cpu, !VAL); ++#endif ++ ++ return false; ++} ++ ++/** ++ * task_call_func - Invoke a function on task in fixed state ++ * @p: Process for which the function is to be invoked, can be @current. ++ * @func: Function to invoke. ++ * @arg: Argument to function. ++ * ++ * Fix the task in it's current state by avoiding wakeups and or rq operations ++ * and call @func(@arg) on it. This function can use ->on_rq and task_curr() ++ * to work out what the state is, if required. Given that @func can be invoked ++ * with a runqueue lock held, it had better be quite lightweight. ++ * ++ * Returns: ++ * Whatever @func returns ++ */ ++int task_call_func(struct task_struct *p, task_call_f func, void *arg) ++{ ++ struct rq *rq = NULL; ++ struct rq_flags rf; ++ int ret; ++ ++ raw_spin_lock_irqsave(&p->pi_lock, rf.flags); ++ ++ if (__task_needs_rq_lock(p)) ++ rq = __task_rq_lock(p, &rf); ++ ++ /* ++ * At this point the task is pinned; either: ++ * - blocked and we're holding off wakeups (pi->lock) ++ * - woken, and we're holding off enqueue (rq->lock) ++ * - queued, and we're holding off schedule (rq->lock) ++ * - running, and we're holding off de-schedule (rq->lock) ++ * ++ * The called function (@func) can use: task_curr(), p->on_rq and ++ * p->__state to differentiate between these states. ++ */ ++ ret = func(p, arg); ++ ++ if (rq) ++ __task_rq_unlock(rq, &rf); ++ ++ raw_spin_unlock_irqrestore(&p->pi_lock, rf.flags); ++ return ret; ++} ++ ++/** ++ * cpu_curr_snapshot - Return a snapshot of the currently running task ++ * @cpu: The CPU on which to snapshot the task. ++ * ++ * Returns the task_struct pointer of the task "currently" running on ++ * the specified CPU. If the same task is running on that CPU throughout, ++ * the return value will be a pointer to that task's task_struct structure. ++ * If the CPU did any context switches even vaguely concurrently with the ++ * execution of this function, the return value will be a pointer to the ++ * task_struct structure of a randomly chosen task that was running on ++ * that CPU somewhere around the time that this function was executing. ++ * ++ * If the specified CPU was offline, the return value is whatever it ++ * is, perhaps a pointer to the task_struct structure of that CPU's idle ++ * task, but there is no guarantee. Callers wishing a useful return ++ * value must take some action to ensure that the specified CPU remains ++ * online throughout. ++ * ++ * This function executes full memory barriers before and after fetching ++ * the pointer, which permits the caller to confine this function's fetch ++ * with respect to the caller's accesses to other shared variables. ++ */ ++struct task_struct *cpu_curr_snapshot(int cpu) ++{ ++ struct task_struct *t; ++ ++ smp_mb(); /* Pairing determined by caller's synchronization design. */ ++ t = rcu_dereference(cpu_curr(cpu)); ++ smp_mb(); /* Pairing determined by caller's synchronization design. */ ++ return t; ++} ++ ++/** ++ * wake_up_process - Wake up a specific process ++ * @p: The process to be woken up. ++ * ++ * Attempt to wake up the nominated process and move it to the set of runnable ++ * processes. ++ * ++ * Return: 1 if the process was woken up, 0 if it was already running. ++ * ++ * This function executes a full memory barrier before accessing the task state. ++ */ ++int wake_up_process(struct task_struct *p) ++{ ++ return try_to_wake_up(p, TASK_NORMAL, 0); ++} ++EXPORT_SYMBOL(wake_up_process); ++ ++int wake_up_state(struct task_struct *p, unsigned int state) ++{ ++ return try_to_wake_up(p, state, 0); ++} ++ ++/* ++ * Perform scheduler related setup for a newly forked process p. ++ * p is forked by current. ++ * ++ * __sched_fork() is basic setup used by init_idle() too: ++ */ ++static inline void __sched_fork(unsigned long clone_flags, struct task_struct *p) ++{ ++ p->on_rq = 0; ++ p->on_cpu = 0; ++ p->utime = 0; ++ p->stime = 0; ++ p->sched_time = 0; ++ ++#ifdef CONFIG_SCHEDSTATS ++ /* Even if schedstat is disabled, there should not be garbage */ ++ memset(&p->stats, 0, sizeof(p->stats)); ++#endif ++ ++#ifdef CONFIG_PREEMPT_NOTIFIERS ++ INIT_HLIST_HEAD(&p->preempt_notifiers); ++#endif ++ ++#ifdef CONFIG_COMPACTION ++ p->capture_control = NULL; ++#endif ++#ifdef CONFIG_SMP ++ p->wake_entry.u_flags = CSD_TYPE_TTWU; ++#endif ++ init_sched_mm_cid(p); ++} ++ ++/* ++ * fork()/clone()-time setup: ++ */ ++int sched_fork(unsigned long clone_flags, struct task_struct *p) ++{ ++ __sched_fork(clone_flags, p); ++ /* ++ * We mark the process as NEW here. This guarantees that ++ * nobody will actually run it, and a signal or other external ++ * event cannot wake it up and insert it on the runqueue either. ++ */ ++ p->__state = TASK_NEW; ++ ++ /* ++ * Make sure we do not leak PI boosting priority to the child. ++ */ ++ p->prio = current->normal_prio; ++ ++ /* ++ * Revert to default priority/policy on fork if requested. ++ */ ++ if (unlikely(p->sched_reset_on_fork)) { ++ if (task_has_rt_policy(p)) { ++ p->policy = SCHED_NORMAL; ++ p->static_prio = NICE_TO_PRIO(0); ++ p->rt_priority = 0; ++ } else if (PRIO_TO_NICE(p->static_prio) < 0) ++ p->static_prio = NICE_TO_PRIO(0); ++ ++ p->prio = p->normal_prio = p->static_prio; ++ ++ /* ++ * We don't need the reset flag anymore after the fork. It has ++ * fulfilled its duty: ++ */ ++ p->sched_reset_on_fork = 0; ++ } ++ ++#ifdef CONFIG_SCHED_INFO ++ if (unlikely(sched_info_on())) ++ memset(&p->sched_info, 0, sizeof(p->sched_info)); ++#endif ++ init_task_preempt_count(p); ++ ++ return 0; ++} ++ ++void sched_cgroup_fork(struct task_struct *p, struct kernel_clone_args *kargs) ++{ ++ unsigned long flags; ++ struct rq *rq; ++ ++ /* ++ * Because we're not yet on the pid-hash, p->pi_lock isn't strictly ++ * required yet, but lockdep gets upset if rules are violated. ++ */ ++ raw_spin_lock_irqsave(&p->pi_lock, flags); ++ /* ++ * Share the timeslice between parent and child, thus the ++ * total amount of pending timeslices in the system doesn't change, ++ * resulting in more scheduling fairness. ++ */ ++ rq = this_rq(); ++ raw_spin_lock(&rq->lock); ++ ++ rq->curr->time_slice /= 2; ++ p->time_slice = rq->curr->time_slice; ++#ifdef CONFIG_SCHED_HRTICK ++ hrtick_start(rq, rq->curr->time_slice); ++#endif ++ ++ if (p->time_slice < RESCHED_NS) { ++ p->time_slice = sched_timeslice_ns; ++ resched_curr(rq); ++ } ++ sched_task_fork(p, rq); ++ raw_spin_unlock(&rq->lock); ++ ++ rseq_migrate(p); ++ /* ++ * We're setting the CPU for the first time, we don't migrate, ++ * so use __set_task_cpu(). ++ */ ++ __set_task_cpu(p, smp_processor_id()); ++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); ++} ++ ++void sched_post_fork(struct task_struct *p) ++{ ++} ++ ++#ifdef CONFIG_SCHEDSTATS ++ ++DEFINE_STATIC_KEY_FALSE(sched_schedstats); ++ ++static void set_schedstats(bool enabled) ++{ ++ if (enabled) ++ static_branch_enable(&sched_schedstats); ++ else ++ static_branch_disable(&sched_schedstats); ++} ++ ++void force_schedstat_enabled(void) ++{ ++ if (!schedstat_enabled()) { ++ pr_info("kernel profiling enabled schedstats, disable via kernel.sched_schedstats.\n"); ++ static_branch_enable(&sched_schedstats); ++ } ++} ++ ++static int __init setup_schedstats(char *str) ++{ ++ int ret = 0; ++ if (!str) ++ goto out; ++ ++ if (!strcmp(str, "enable")) { ++ set_schedstats(true); ++ ret = 1; ++ } else if (!strcmp(str, "disable")) { ++ set_schedstats(false); ++ ret = 1; ++ } ++out: ++ if (!ret) ++ pr_warn("Unable to parse schedstats=\n"); ++ ++ return ret; ++} ++__setup("schedstats=", setup_schedstats); ++ ++#ifdef CONFIG_PROC_SYSCTL ++static int sysctl_schedstats(struct ctl_table *table, int write, void *buffer, ++ size_t *lenp, loff_t *ppos) ++{ ++ struct ctl_table t; ++ int err; ++ int state = static_branch_likely(&sched_schedstats); ++ ++ if (write && !capable(CAP_SYS_ADMIN)) ++ return -EPERM; ++ ++ t = *table; ++ t.data = &state; ++ err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos); ++ if (err < 0) ++ return err; ++ if (write) ++ set_schedstats(state); ++ return err; ++} ++ ++static struct ctl_table sched_core_sysctls[] = { ++ { ++ .procname = "sched_schedstats", ++ .data = NULL, ++ .maxlen = sizeof(unsigned int), ++ .mode = 0644, ++ .proc_handler = sysctl_schedstats, ++ .extra1 = SYSCTL_ZERO, ++ .extra2 = SYSCTL_ONE, ++ }, ++ {} ++}; ++static int __init sched_core_sysctl_init(void) ++{ ++ register_sysctl_init("kernel", sched_core_sysctls); ++ return 0; ++} ++late_initcall(sched_core_sysctl_init); ++#endif /* CONFIG_PROC_SYSCTL */ ++#endif /* CONFIG_SCHEDSTATS */ ++ ++/* ++ * wake_up_new_task - wake up a newly created task for the first time. ++ * ++ * This function will do some initial scheduler statistics housekeeping ++ * that must be done for every newly created context, then puts the task ++ * on the runqueue and wakes it. ++ */ ++void wake_up_new_task(struct task_struct *p) ++{ ++ unsigned long flags; ++ struct rq *rq; ++ ++ raw_spin_lock_irqsave(&p->pi_lock, flags); ++ WRITE_ONCE(p->__state, TASK_RUNNING); ++ rq = cpu_rq(select_task_rq(p)); ++#ifdef CONFIG_SMP ++ rseq_migrate(p); ++ /* ++ * Fork balancing, do it here and not earlier because: ++ * - cpus_ptr can change in the fork path ++ * - any previously selected CPU might disappear through hotplug ++ * ++ * Use __set_task_cpu() to avoid calling sched_class::migrate_task_rq, ++ * as we're not fully set-up yet. ++ */ ++ __set_task_cpu(p, cpu_of(rq)); ++#endif ++ ++ raw_spin_lock(&rq->lock); ++ update_rq_clock(rq); ++ ++ activate_task(p, rq); ++ trace_sched_wakeup_new(p); ++ wakeup_preempt(rq); ++ ++ raw_spin_unlock(&rq->lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); ++} ++ ++#ifdef CONFIG_PREEMPT_NOTIFIERS ++ ++static DEFINE_STATIC_KEY_FALSE(preempt_notifier_key); ++ ++void preempt_notifier_inc(void) ++{ ++ static_branch_inc(&preempt_notifier_key); ++} ++EXPORT_SYMBOL_GPL(preempt_notifier_inc); ++ ++void preempt_notifier_dec(void) ++{ ++ static_branch_dec(&preempt_notifier_key); ++} ++EXPORT_SYMBOL_GPL(preempt_notifier_dec); ++ ++/** ++ * preempt_notifier_register - tell me when current is being preempted & rescheduled ++ * @notifier: notifier struct to register ++ */ ++void preempt_notifier_register(struct preempt_notifier *notifier) ++{ ++ if (!static_branch_unlikely(&preempt_notifier_key)) ++ WARN(1, "registering preempt_notifier while notifiers disabled\n"); ++ ++ hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); ++} ++EXPORT_SYMBOL_GPL(preempt_notifier_register); ++ ++/** ++ * preempt_notifier_unregister - no longer interested in preemption notifications ++ * @notifier: notifier struct to unregister ++ * ++ * This is *not* safe to call from within a preemption notifier. ++ */ ++void preempt_notifier_unregister(struct preempt_notifier *notifier) ++{ ++ hlist_del(¬ifier->link); ++} ++EXPORT_SYMBOL_GPL(preempt_notifier_unregister); ++ ++static void __fire_sched_in_preempt_notifiers(struct task_struct *curr) ++{ ++ struct preempt_notifier *notifier; ++ ++ hlist_for_each_entry(notifier, &curr->preempt_notifiers, link) ++ notifier->ops->sched_in(notifier, raw_smp_processor_id()); ++} ++ ++static __always_inline void fire_sched_in_preempt_notifiers(struct task_struct *curr) ++{ ++ if (static_branch_unlikely(&preempt_notifier_key)) ++ __fire_sched_in_preempt_notifiers(curr); ++} ++ ++static void ++__fire_sched_out_preempt_notifiers(struct task_struct *curr, ++ struct task_struct *next) ++{ ++ struct preempt_notifier *notifier; ++ ++ hlist_for_each_entry(notifier, &curr->preempt_notifiers, link) ++ notifier->ops->sched_out(notifier, next); ++} ++ ++static __always_inline void ++fire_sched_out_preempt_notifiers(struct task_struct *curr, ++ struct task_struct *next) ++{ ++ if (static_branch_unlikely(&preempt_notifier_key)) ++ __fire_sched_out_preempt_notifiers(curr, next); ++} ++ ++#else /* !CONFIG_PREEMPT_NOTIFIERS */ ++ ++static inline void fire_sched_in_preempt_notifiers(struct task_struct *curr) ++{ ++} ++ ++static inline void ++fire_sched_out_preempt_notifiers(struct task_struct *curr, ++ struct task_struct *next) ++{ ++} ++ ++#endif /* CONFIG_PREEMPT_NOTIFIERS */ ++ ++static inline void prepare_task(struct task_struct *next) ++{ ++ /* ++ * Claim the task as running, we do this before switching to it ++ * such that any running task will have this set. ++ * ++ * See the smp_load_acquire(&p->on_cpu) case in ttwu() and ++ * its ordering comment. ++ */ ++ WRITE_ONCE(next->on_cpu, 1); ++} ++ ++static inline void finish_task(struct task_struct *prev) ++{ ++#ifdef CONFIG_SMP ++ /* ++ * This must be the very last reference to @prev from this CPU. After ++ * p->on_cpu is cleared, the task can be moved to a different CPU. We ++ * must ensure this doesn't happen until the switch is completely ++ * finished. ++ * ++ * In particular, the load of prev->state in finish_task_switch() must ++ * happen before this. ++ * ++ * Pairs with the smp_cond_load_acquire() in try_to_wake_up(). ++ */ ++ smp_store_release(&prev->on_cpu, 0); ++#else ++ prev->on_cpu = 0; ++#endif ++} ++ ++#ifdef CONFIG_SMP ++ ++static void do_balance_callbacks(struct rq *rq, struct balance_callback *head) ++{ ++ void (*func)(struct rq *rq); ++ struct balance_callback *next; ++ ++ lockdep_assert_held(&rq->lock); ++ ++ while (head) { ++ func = (void (*)(struct rq *))head->func; ++ next = head->next; ++ head->next = NULL; ++ head = next; ++ ++ func(rq); ++ } ++} ++ ++static void balance_push(struct rq *rq); ++ ++/* ++ * balance_push_callback is a right abuse of the callback interface and plays ++ * by significantly different rules. ++ * ++ * Where the normal balance_callback's purpose is to be ran in the same context ++ * that queued it (only later, when it's safe to drop rq->lock again), ++ * balance_push_callback is specifically targeted at __schedule(). ++ * ++ * This abuse is tolerated because it places all the unlikely/odd cases behind ++ * a single test, namely: rq->balance_callback == NULL. ++ */ ++struct balance_callback balance_push_callback = { ++ .next = NULL, ++ .func = balance_push, ++}; ++ ++static inline struct balance_callback * ++__splice_balance_callbacks(struct rq *rq, bool split) ++{ ++ struct balance_callback *head = rq->balance_callback; ++ ++ if (likely(!head)) ++ return NULL; ++ ++ lockdep_assert_rq_held(rq); ++ /* ++ * Must not take balance_push_callback off the list when ++ * splice_balance_callbacks() and balance_callbacks() are not ++ * in the same rq->lock section. ++ * ++ * In that case it would be possible for __schedule() to interleave ++ * and observe the list empty. ++ */ ++ if (split && head == &balance_push_callback) ++ head = NULL; ++ else ++ rq->balance_callback = NULL; ++ ++ return head; ++} ++ ++static inline struct balance_callback *splice_balance_callbacks(struct rq *rq) ++{ ++ return __splice_balance_callbacks(rq, true); ++} ++ ++static void __balance_callbacks(struct rq *rq) ++{ ++ do_balance_callbacks(rq, __splice_balance_callbacks(rq, false)); ++} ++ ++static inline void balance_callbacks(struct rq *rq, struct balance_callback *head) ++{ ++ unsigned long flags; ++ ++ if (unlikely(head)) { ++ raw_spin_lock_irqsave(&rq->lock, flags); ++ do_balance_callbacks(rq, head); ++ raw_spin_unlock_irqrestore(&rq->lock, flags); ++ } ++} ++ ++#else ++ ++static inline void __balance_callbacks(struct rq *rq) ++{ ++} ++ ++static inline struct balance_callback *splice_balance_callbacks(struct rq *rq) ++{ ++ return NULL; ++} ++ ++static inline void balance_callbacks(struct rq *rq, struct balance_callback *head) ++{ ++} ++ ++#endif ++ ++static inline void ++prepare_lock_switch(struct rq *rq, struct task_struct *next) ++{ ++ /* ++ * Since the runqueue lock will be released by the next ++ * task (which is an invalid locking op but in the case ++ * of the scheduler it's an obvious special-case), so we ++ * do an early lockdep release here: ++ */ ++ spin_release(&rq->lock.dep_map, _THIS_IP_); ++#ifdef CONFIG_DEBUG_SPINLOCK ++ /* this is a valid case when another task releases the spinlock */ ++ rq->lock.owner = next; ++#endif ++} ++ ++static inline void finish_lock_switch(struct rq *rq) ++{ ++ /* ++ * If we are tracking spinlock dependencies then we have to ++ * fix up the runqueue lock - which gets 'carried over' from ++ * prev into current: ++ */ ++ spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); ++ __balance_callbacks(rq); ++ raw_spin_unlock_irq(&rq->lock); ++} ++ ++/* ++ * NOP if the arch has not defined these: ++ */ ++ ++#ifndef prepare_arch_switch ++# define prepare_arch_switch(next) do { } while (0) ++#endif ++ ++#ifndef finish_arch_post_lock_switch ++# define finish_arch_post_lock_switch() do { } while (0) ++#endif ++ ++static inline void kmap_local_sched_out(void) ++{ ++#ifdef CONFIG_KMAP_LOCAL ++ if (unlikely(current->kmap_ctrl.idx)) ++ __kmap_local_sched_out(); ++#endif ++} ++ ++static inline void kmap_local_sched_in(void) ++{ ++#ifdef CONFIG_KMAP_LOCAL ++ if (unlikely(current->kmap_ctrl.idx)) ++ __kmap_local_sched_in(); ++#endif ++} ++ ++/** ++ * prepare_task_switch - prepare to switch tasks ++ * @rq: the runqueue preparing to switch ++ * @next: the task we are going to switch to. ++ * ++ * This is called with the rq lock held and interrupts off. It must ++ * be paired with a subsequent finish_task_switch after the context ++ * switch. ++ * ++ * prepare_task_switch sets up locking and calls architecture specific ++ * hooks. ++ */ ++static inline void ++prepare_task_switch(struct rq *rq, struct task_struct *prev, ++ struct task_struct *next) ++{ ++ kcov_prepare_switch(prev); ++ sched_info_switch(rq, prev, next); ++ perf_event_task_sched_out(prev, next); ++ rseq_preempt(prev); ++ fire_sched_out_preempt_notifiers(prev, next); ++ kmap_local_sched_out(); ++ prepare_task(next); ++ prepare_arch_switch(next); ++} ++ ++/** ++ * finish_task_switch - clean up after a task-switch ++ * @rq: runqueue associated with task-switch ++ * @prev: the thread we just switched away from. ++ * ++ * finish_task_switch must be called after the context switch, paired ++ * with a prepare_task_switch call before the context switch. ++ * finish_task_switch will reconcile locking set up by prepare_task_switch, ++ * and do any other architecture-specific cleanup actions. ++ * ++ * Note that we may have delayed dropping an mm in context_switch(). If ++ * so, we finish that here outside of the runqueue lock. (Doing it ++ * with the lock held can cause deadlocks; see schedule() for ++ * details.) ++ * ++ * The context switch have flipped the stack from under us and restored the ++ * local variables which were saved when this task called schedule() in the ++ * past. prev == current is still correct but we need to recalculate this_rq ++ * because prev may have moved to another CPU. ++ */ ++static struct rq *finish_task_switch(struct task_struct *prev) ++ __releases(rq->lock) ++{ ++ struct rq *rq = this_rq(); ++ struct mm_struct *mm = rq->prev_mm; ++ unsigned int prev_state; ++ ++ /* ++ * The previous task will have left us with a preempt_count of 2 ++ * because it left us after: ++ * ++ * schedule() ++ * preempt_disable(); // 1 ++ * __schedule() ++ * raw_spin_lock_irq(&rq->lock) // 2 ++ * ++ * Also, see FORK_PREEMPT_COUNT. ++ */ ++ if (WARN_ONCE(preempt_count() != 2*PREEMPT_DISABLE_OFFSET, ++ "corrupted preempt_count: %s/%d/0x%x\n", ++ current->comm, current->pid, preempt_count())) ++ preempt_count_set(FORK_PREEMPT_COUNT); ++ ++ rq->prev_mm = NULL; ++ ++ /* ++ * A task struct has one reference for the use as "current". ++ * If a task dies, then it sets TASK_DEAD in tsk->state and calls ++ * schedule one last time. The schedule call will never return, and ++ * the scheduled task must drop that reference. ++ * ++ * We must observe prev->state before clearing prev->on_cpu (in ++ * finish_task), otherwise a concurrent wakeup can get prev ++ * running on another CPU and we could rave with its RUNNING -> DEAD ++ * transition, resulting in a double drop. ++ */ ++ prev_state = READ_ONCE(prev->__state); ++ vtime_task_switch(prev); ++ perf_event_task_sched_in(prev, current); ++ finish_task(prev); ++ tick_nohz_task_switch(); ++ finish_lock_switch(rq); ++ finish_arch_post_lock_switch(); ++ kcov_finish_switch(current); ++ /* ++ * kmap_local_sched_out() is invoked with rq::lock held and ++ * interrupts disabled. There is no requirement for that, but the ++ * sched out code does not have an interrupt enabled section. ++ * Restoring the maps on sched in does not require interrupts being ++ * disabled either. ++ */ ++ kmap_local_sched_in(); ++ ++ fire_sched_in_preempt_notifiers(current); ++ /* ++ * When switching through a kernel thread, the loop in ++ * membarrier_{private,global}_expedited() may have observed that ++ * kernel thread and not issued an IPI. It is therefore possible to ++ * schedule between user->kernel->user threads without passing though ++ * switch_mm(). Membarrier requires a barrier after storing to ++ * rq->curr, before returning to userspace, so provide them here: ++ * ++ * - a full memory barrier for {PRIVATE,GLOBAL}_EXPEDITED, implicitly ++ * provided by mmdrop(), ++ * - a sync_core for SYNC_CORE. ++ */ ++ if (mm) { ++ membarrier_mm_sync_core_before_usermode(mm); ++ mmdrop_sched(mm); ++ } ++ if (unlikely(prev_state == TASK_DEAD)) { ++ /* Task is done with its stack. */ ++ put_task_stack(prev); ++ ++ put_task_struct_rcu_user(prev); ++ } ++ ++ return rq; ++} ++ ++/** ++ * schedule_tail - first thing a freshly forked thread must call. ++ * @prev: the thread we just switched away from. ++ */ ++asmlinkage __visible void schedule_tail(struct task_struct *prev) ++ __releases(rq->lock) ++{ ++ /* ++ * New tasks start with FORK_PREEMPT_COUNT, see there and ++ * finish_task_switch() for details. ++ * ++ * finish_task_switch() will drop rq->lock() and lower preempt_count ++ * and the preempt_enable() will end up enabling preemption (on ++ * PREEMPT_COUNT kernels). ++ */ ++ ++ finish_task_switch(prev); ++ preempt_enable(); ++ ++ if (current->set_child_tid) ++ put_user(task_pid_vnr(current), current->set_child_tid); ++ ++ calculate_sigpending(); ++} ++ ++/* ++ * context_switch - switch to the new MM and the new thread's register state. ++ */ ++static __always_inline struct rq * ++context_switch(struct rq *rq, struct task_struct *prev, ++ struct task_struct *next) ++{ ++ prepare_task_switch(rq, prev, next); ++ ++ /* ++ * For paravirt, this is coupled with an exit in switch_to to ++ * combine the page table reload and the switch backend into ++ * one hypercall. ++ */ ++ arch_start_context_switch(prev); ++ ++ /* ++ * kernel -> kernel lazy + transfer active ++ * user -> kernel lazy + mmgrab() active ++ * ++ * kernel -> user switch + mmdrop() active ++ * user -> user switch ++ * ++ * switch_mm_cid() needs to be updated if the barriers provided ++ * by context_switch() are modified. ++ */ ++ if (!next->mm) { // to kernel ++ enter_lazy_tlb(prev->active_mm, next); ++ ++ next->active_mm = prev->active_mm; ++ if (prev->mm) // from user ++ mmgrab(prev->active_mm); ++ else ++ prev->active_mm = NULL; ++ } else { // to user ++ membarrier_switch_mm(rq, prev->active_mm, next->mm); ++ /* ++ * sys_membarrier() requires an smp_mb() between setting ++ * rq->curr / membarrier_switch_mm() and returning to userspace. ++ * ++ * The below provides this either through switch_mm(), or in ++ * case 'prev->active_mm == next->mm' through ++ * finish_task_switch()'s mmdrop(). ++ */ ++ switch_mm_irqs_off(prev->active_mm, next->mm, next); ++ lru_gen_use_mm(next->mm); ++ ++ if (!prev->mm) { // from kernel ++ /* will mmdrop() in finish_task_switch(). */ ++ rq->prev_mm = prev->active_mm; ++ prev->active_mm = NULL; ++ } ++ } ++ ++ /* switch_mm_cid() requires the memory barriers above. */ ++ switch_mm_cid(rq, prev, next); ++ ++ prepare_lock_switch(rq, next); ++ ++ /* Here we just switch the register state and the stack. */ ++ switch_to(prev, next, prev); ++ barrier(); ++ ++ return finish_task_switch(prev); ++} ++ ++/* ++ * nr_running, nr_uninterruptible and nr_context_switches: ++ * ++ * externally visible scheduler statistics: current number of runnable ++ * threads, total number of context switches performed since bootup. ++ */ ++unsigned int nr_running(void) ++{ ++ unsigned int i, sum = 0; ++ ++ for_each_online_cpu(i) ++ sum += cpu_rq(i)->nr_running; ++ ++ return sum; ++} ++ ++/* ++ * Check if only the current task is running on the CPU. ++ * ++ * Caution: this function does not check that the caller has disabled ++ * preemption, thus the result might have a time-of-check-to-time-of-use ++ * race. The caller is responsible to use it correctly, for example: ++ * ++ * - from a non-preemptible section (of course) ++ * ++ * - from a thread that is bound to a single CPU ++ * ++ * - in a loop with very short iterations (e.g. a polling loop) ++ */ ++bool single_task_running(void) ++{ ++ return raw_rq()->nr_running == 1; ++} ++EXPORT_SYMBOL(single_task_running); ++ ++unsigned long long nr_context_switches_cpu(int cpu) ++{ ++ return cpu_rq(cpu)->nr_switches; ++} ++ ++unsigned long long nr_context_switches(void) ++{ ++ int i; ++ unsigned long long sum = 0; ++ ++ for_each_possible_cpu(i) ++ sum += cpu_rq(i)->nr_switches; ++ ++ return sum; ++} ++ ++/* ++ * Consumers of these two interfaces, like for example the cpuidle menu ++ * governor, are using nonsensical data. Preferring shallow idle state selection ++ * for a CPU that has IO-wait which might not even end up running the task when ++ * it does become runnable. ++ */ ++ ++unsigned int nr_iowait_cpu(int cpu) ++{ ++ return atomic_read(&cpu_rq(cpu)->nr_iowait); ++} ++ ++/* ++ * IO-wait accounting, and how it's mostly bollocks (on SMP). ++ * ++ * The idea behind IO-wait account is to account the idle time that we could ++ * have spend running if it were not for IO. That is, if we were to improve the ++ * storage performance, we'd have a proportional reduction in IO-wait time. ++ * ++ * This all works nicely on UP, where, when a task blocks on IO, we account ++ * idle time as IO-wait, because if the storage were faster, it could've been ++ * running and we'd not be idle. ++ * ++ * This has been extended to SMP, by doing the same for each CPU. This however ++ * is broken. ++ * ++ * Imagine for instance the case where two tasks block on one CPU, only the one ++ * CPU will have IO-wait accounted, while the other has regular idle. Even ++ * though, if the storage were faster, both could've ran at the same time, ++ * utilising both CPUs. ++ * ++ * This means, that when looking globally, the current IO-wait accounting on ++ * SMP is a lower bound, by reason of under accounting. ++ * ++ * Worse, since the numbers are provided per CPU, they are sometimes ++ * interpreted per CPU, and that is nonsensical. A blocked task isn't strictly ++ * associated with any one particular CPU, it can wake to another CPU than it ++ * blocked on. This means the per CPU IO-wait number is meaningless. ++ * ++ * Task CPU affinities can make all that even more 'interesting'. ++ */ ++ ++unsigned int nr_iowait(void) ++{ ++ unsigned int i, sum = 0; ++ ++ for_each_possible_cpu(i) ++ sum += nr_iowait_cpu(i); ++ ++ return sum; ++} ++ ++#ifdef CONFIG_SMP ++ ++/* ++ * sched_exec - execve() is a valuable balancing opportunity, because at ++ * this point the task has the smallest effective memory and cache ++ * footprint. ++ */ ++void sched_exec(void) ++{ ++} ++ ++#endif ++ ++DEFINE_PER_CPU(struct kernel_stat, kstat); ++DEFINE_PER_CPU(struct kernel_cpustat, kernel_cpustat); ++ ++EXPORT_PER_CPU_SYMBOL(kstat); ++EXPORT_PER_CPU_SYMBOL(kernel_cpustat); ++ ++static inline void update_curr(struct rq *rq, struct task_struct *p) ++{ ++ s64 ns = rq->clock_task - p->last_ran; ++ ++ p->sched_time += ns; ++ cgroup_account_cputime(p, ns); ++ account_group_exec_runtime(p, ns); ++ ++ p->time_slice -= ns; ++ p->last_ran = rq->clock_task; ++} ++ ++/* ++ * Return accounted runtime for the task. ++ * Return separately the current's pending runtime that have not been ++ * accounted yet. ++ */ ++unsigned long long task_sched_runtime(struct task_struct *p) ++{ ++ unsigned long flags; ++ struct rq *rq; ++ raw_spinlock_t *lock; ++ u64 ns; ++ ++#if defined(CONFIG_64BIT) && defined(CONFIG_SMP) ++ /* ++ * 64-bit doesn't need locks to atomically read a 64-bit value. ++ * So we have a optimization chance when the task's delta_exec is 0. ++ * Reading ->on_cpu is racy, but this is ok. ++ * ++ * If we race with it leaving CPU, we'll take a lock. So we're correct. ++ * If we race with it entering CPU, unaccounted time is 0. This is ++ * indistinguishable from the read occurring a few cycles earlier. ++ * If we see ->on_cpu without ->on_rq, the task is leaving, and has ++ * been accounted, so we're correct here as well. ++ */ ++ if (!p->on_cpu || !task_on_rq_queued(p)) ++ return tsk_seruntime(p); ++#endif ++ ++ rq = task_access_lock_irqsave(p, &lock, &flags); ++ /* ++ * Must be ->curr _and_ ->on_rq. If dequeued, we would ++ * project cycles that may never be accounted to this ++ * thread, breaking clock_gettime(). ++ */ ++ if (p == rq->curr && task_on_rq_queued(p)) { ++ update_rq_clock(rq); ++ update_curr(rq, p); ++ } ++ ns = tsk_seruntime(p); ++ task_access_unlock_irqrestore(p, lock, &flags); ++ ++ return ns; ++} ++ ++/* This manages tasks that have run out of timeslice during a scheduler_tick */ ++static inline void scheduler_task_tick(struct rq *rq) ++{ ++ struct task_struct *p = rq->curr; ++ ++ if (is_idle_task(p)) ++ return; ++ ++ update_curr(rq, p); ++ cpufreq_update_util(rq, 0); ++ ++ /* ++ * Tasks have less than RESCHED_NS of time slice left they will be ++ * rescheduled. ++ */ ++ if (p->time_slice >= RESCHED_NS) ++ return; ++ set_tsk_need_resched(p); ++ set_preempt_need_resched(); ++} ++ ++#ifdef CONFIG_SCHED_DEBUG ++static u64 cpu_resched_latency(struct rq *rq) ++{ ++ int latency_warn_ms = READ_ONCE(sysctl_resched_latency_warn_ms); ++ u64 resched_latency, now = rq_clock(rq); ++ static bool warned_once; ++ ++ if (sysctl_resched_latency_warn_once && warned_once) ++ return 0; ++ ++ if (!need_resched() || !latency_warn_ms) ++ return 0; ++ ++ if (system_state == SYSTEM_BOOTING) ++ return 0; ++ ++ if (!rq->last_seen_need_resched_ns) { ++ rq->last_seen_need_resched_ns = now; ++ rq->ticks_without_resched = 0; ++ return 0; ++ } ++ ++ rq->ticks_without_resched++; ++ resched_latency = now - rq->last_seen_need_resched_ns; ++ if (resched_latency <= latency_warn_ms * NSEC_PER_MSEC) ++ return 0; ++ ++ warned_once = true; ++ ++ return resched_latency; ++} ++ ++static int __init setup_resched_latency_warn_ms(char *str) ++{ ++ long val; ++ ++ if ((kstrtol(str, 0, &val))) { ++ pr_warn("Unable to set resched_latency_warn_ms\n"); ++ return 1; ++ } ++ ++ sysctl_resched_latency_warn_ms = val; ++ return 1; ++} ++__setup("resched_latency_warn_ms=", setup_resched_latency_warn_ms); ++#else ++static inline u64 cpu_resched_latency(struct rq *rq) { return 0; } ++#endif /* CONFIG_SCHED_DEBUG */ ++ ++/* ++ * This function gets called by the timer code, with HZ frequency. ++ * We call it with interrupts disabled. ++ */ ++void scheduler_tick(void) ++{ ++ int cpu __maybe_unused = smp_processor_id(); ++ struct rq *rq = cpu_rq(cpu); ++ struct task_struct *curr = rq->curr; ++ u64 resched_latency; ++ ++ if (housekeeping_cpu(cpu, HK_TYPE_TICK)) ++ arch_scale_freq_tick(); ++ ++ sched_clock_tick(); ++ ++ raw_spin_lock(&rq->lock); ++ update_rq_clock(rq); ++ ++ scheduler_task_tick(rq); ++ if (sched_feat(LATENCY_WARN)) ++ resched_latency = cpu_resched_latency(rq); ++ calc_global_load_tick(rq); ++ ++ task_tick_mm_cid(rq, rq->curr); ++ ++ raw_spin_unlock(&rq->lock); ++ ++ if (sched_feat(LATENCY_WARN) && resched_latency) ++ resched_latency_warn(cpu, resched_latency); ++ ++ perf_event_task_tick(); ++ ++ if (curr->flags & PF_WQ_WORKER) ++ wq_worker_tick(curr); ++} ++ ++#ifdef CONFIG_SCHED_SMT ++static inline int sg_balance_cpu_stop(void *data) ++{ ++ struct rq *rq = this_rq(); ++ struct task_struct *p = data; ++ cpumask_t tmp; ++ unsigned long flags; ++ ++ local_irq_save(flags); ++ ++ raw_spin_lock(&p->pi_lock); ++ raw_spin_lock(&rq->lock); ++ ++ rq->active_balance = 0; ++ /* _something_ may have changed the task, double check again */ ++ if (task_on_rq_queued(p) && task_rq(p) == rq && ++ cpumask_and(&tmp, p->cpus_ptr, &sched_sg_idle_mask) && ++ !is_migration_disabled(p)) { ++ int cpu = cpu_of(rq); ++ int dcpu = __best_mask_cpu(&tmp, per_cpu(sched_cpu_llc_mask, cpu)); ++ rq = move_queued_task(rq, p, dcpu); ++ } ++ ++ raw_spin_unlock(&rq->lock); ++ raw_spin_unlock(&p->pi_lock); ++ ++ local_irq_restore(flags); ++ ++ return 0; ++} ++ ++/* sg_balance_trigger - trigger slibing group balance for @cpu */ ++static inline int sg_balance_trigger(const int cpu) ++{ ++ struct rq *rq= cpu_rq(cpu); ++ unsigned long flags; ++ struct task_struct *curr; ++ int res; ++ ++ if (!raw_spin_trylock_irqsave(&rq->lock, flags)) ++ return 0; ++ curr = rq->curr; ++ res = (!is_idle_task(curr)) && (1 == rq->nr_running) &&\ ++ cpumask_intersects(curr->cpus_ptr, &sched_sg_idle_mask) &&\ ++ !is_migration_disabled(curr) && (!rq->active_balance); ++ ++ if (res) ++ rq->active_balance = 1; ++ ++ raw_spin_unlock_irqrestore(&rq->lock, flags); ++ ++ if (res) ++ stop_one_cpu_nowait(cpu, sg_balance_cpu_stop, curr, ++ &rq->active_balance_work); ++ return res; ++} ++ ++/* ++ * sg_balance - slibing group balance check for run queue @rq ++ */ ++static inline void sg_balance(struct rq *rq, int cpu) ++{ ++ cpumask_t chk; ++ ++ /* exit when cpu is offline */ ++ if (unlikely(!rq->online)) ++ return; ++ ++ /* ++ * Only cpu in slibing idle group will do the checking and then ++ * find potential cpus which can migrate the current running task ++ */ ++ if (cpumask_test_cpu(cpu, &sched_sg_idle_mask) && ++ cpumask_andnot(&chk, cpu_online_mask, sched_idle_mask) && ++ cpumask_andnot(&chk, &chk, &sched_rq_pending_mask)) { ++ int i; ++ ++ for_each_cpu_wrap(i, &chk, cpu) { ++ if (!cpumask_intersects(cpu_smt_mask(i), sched_idle_mask) &&\ ++ sg_balance_trigger(i)) ++ return; ++ } ++ } ++} ++#endif /* CONFIG_SCHED_SMT */ ++ ++#ifdef CONFIG_NO_HZ_FULL ++ ++struct tick_work { ++ int cpu; ++ atomic_t state; ++ struct delayed_work work; ++}; ++/* Values for ->state, see diagram below. */ ++#define TICK_SCHED_REMOTE_OFFLINE 0 ++#define TICK_SCHED_REMOTE_OFFLINING 1 ++#define TICK_SCHED_REMOTE_RUNNING 2 ++ ++/* ++ * State diagram for ->state: ++ * ++ * ++ * TICK_SCHED_REMOTE_OFFLINE ++ * | ^ ++ * | | ++ * | | sched_tick_remote() ++ * | | ++ * | | ++ * +--TICK_SCHED_REMOTE_OFFLINING ++ * | ^ ++ * | | ++ * sched_tick_start() | | sched_tick_stop() ++ * | | ++ * V | ++ * TICK_SCHED_REMOTE_RUNNING ++ * ++ * ++ * Other transitions get WARN_ON_ONCE(), except that sched_tick_remote() ++ * and sched_tick_start() are happy to leave the state in RUNNING. ++ */ ++ ++static struct tick_work __percpu *tick_work_cpu; ++ ++static void sched_tick_remote(struct work_struct *work) ++{ ++ struct delayed_work *dwork = to_delayed_work(work); ++ struct tick_work *twork = container_of(dwork, struct tick_work, work); ++ int cpu = twork->cpu; ++ struct rq *rq = cpu_rq(cpu); ++ int os; ++ ++ /* ++ * Handle the tick only if it appears the remote CPU is running in full ++ * dynticks mode. The check is racy by nature, but missing a tick or ++ * having one too much is no big deal because the scheduler tick updates ++ * statistics and checks timeslices in a time-independent way, regardless ++ * of when exactly it is running. ++ */ ++ if (tick_nohz_tick_stopped_cpu(cpu)) { ++ guard(raw_spinlock_irqsave)(&rq->lock); ++ struct task_struct *curr = rq->curr; ++ ++ if (cpu_online(cpu)) { ++ update_rq_clock(rq); ++ ++ if (!is_idle_task(curr)) { ++ /* ++ * Make sure the next tick runs within a ++ * reasonable amount of time. ++ */ ++ u64 delta = rq_clock_task(rq) - curr->last_ran; ++ WARN_ON_ONCE(delta > (u64)NSEC_PER_SEC * 3); ++ } ++ scheduler_task_tick(rq); ++ ++ calc_load_nohz_remote(rq); ++ } ++ } ++ ++ /* ++ * Run the remote tick once per second (1Hz). This arbitrary ++ * frequency is large enough to avoid overload but short enough ++ * to keep scheduler internal stats reasonably up to date. But ++ * first update state to reflect hotplug activity if required. ++ */ ++ os = atomic_fetch_add_unless(&twork->state, -1, TICK_SCHED_REMOTE_RUNNING); ++ WARN_ON_ONCE(os == TICK_SCHED_REMOTE_OFFLINE); ++ if (os == TICK_SCHED_REMOTE_RUNNING) ++ queue_delayed_work(system_unbound_wq, dwork, HZ); ++} ++ ++static void sched_tick_start(int cpu) ++{ ++ int os; ++ struct tick_work *twork; ++ ++ if (housekeeping_cpu(cpu, HK_TYPE_TICK)) ++ return; ++ ++ WARN_ON_ONCE(!tick_work_cpu); ++ ++ twork = per_cpu_ptr(tick_work_cpu, cpu); ++ os = atomic_xchg(&twork->state, TICK_SCHED_REMOTE_RUNNING); ++ WARN_ON_ONCE(os == TICK_SCHED_REMOTE_RUNNING); ++ if (os == TICK_SCHED_REMOTE_OFFLINE) { ++ twork->cpu = cpu; ++ INIT_DELAYED_WORK(&twork->work, sched_tick_remote); ++ queue_delayed_work(system_unbound_wq, &twork->work, HZ); ++ } ++} ++ ++#ifdef CONFIG_HOTPLUG_CPU ++static void sched_tick_stop(int cpu) ++{ ++ struct tick_work *twork; ++ int os; ++ ++ if (housekeeping_cpu(cpu, HK_TYPE_TICK)) ++ return; ++ ++ WARN_ON_ONCE(!tick_work_cpu); ++ ++ twork = per_cpu_ptr(tick_work_cpu, cpu); ++ /* There cannot be competing actions, but don't rely on stop-machine. */ ++ os = atomic_xchg(&twork->state, TICK_SCHED_REMOTE_OFFLINING); ++ WARN_ON_ONCE(os != TICK_SCHED_REMOTE_RUNNING); ++ /* Don't cancel, as this would mess up the state machine. */ ++} ++#endif /* CONFIG_HOTPLUG_CPU */ ++ ++int __init sched_tick_offload_init(void) ++{ ++ tick_work_cpu = alloc_percpu(struct tick_work); ++ BUG_ON(!tick_work_cpu); ++ return 0; ++} ++ ++#else /* !CONFIG_NO_HZ_FULL */ ++static inline void sched_tick_start(int cpu) { } ++static inline void sched_tick_stop(int cpu) { } ++#endif ++ ++#if defined(CONFIG_PREEMPTION) && (defined(CONFIG_DEBUG_PREEMPT) || \ ++ defined(CONFIG_PREEMPT_TRACER)) ++/* ++ * If the value passed in is equal to the current preempt count ++ * then we just disabled preemption. Start timing the latency. ++ */ ++static inline void preempt_latency_start(int val) ++{ ++ if (preempt_count() == val) { ++ unsigned long ip = get_lock_parent_ip(); ++#ifdef CONFIG_DEBUG_PREEMPT ++ current->preempt_disable_ip = ip; ++#endif ++ trace_preempt_off(CALLER_ADDR0, ip); ++ } ++} ++ ++void preempt_count_add(int val) ++{ ++#ifdef CONFIG_DEBUG_PREEMPT ++ /* ++ * Underflow? ++ */ ++ if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) ++ return; ++#endif ++ __preempt_count_add(val); ++#ifdef CONFIG_DEBUG_PREEMPT ++ /* ++ * Spinlock count overflowing soon? ++ */ ++ DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= ++ PREEMPT_MASK - 10); ++#endif ++ preempt_latency_start(val); ++} ++EXPORT_SYMBOL(preempt_count_add); ++NOKPROBE_SYMBOL(preempt_count_add); ++ ++/* ++ * If the value passed in equals to the current preempt count ++ * then we just enabled preemption. Stop timing the latency. ++ */ ++static inline void preempt_latency_stop(int val) ++{ ++ if (preempt_count() == val) ++ trace_preempt_on(CALLER_ADDR0, get_lock_parent_ip()); ++} ++ ++void preempt_count_sub(int val) ++{ ++#ifdef CONFIG_DEBUG_PREEMPT ++ /* ++ * Underflow? ++ */ ++ if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) ++ return; ++ /* ++ * Is the spinlock portion underflowing? ++ */ ++ if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && ++ !(preempt_count() & PREEMPT_MASK))) ++ return; ++#endif ++ ++ preempt_latency_stop(val); ++ __preempt_count_sub(val); ++} ++EXPORT_SYMBOL(preempt_count_sub); ++NOKPROBE_SYMBOL(preempt_count_sub); ++ ++#else ++static inline void preempt_latency_start(int val) { } ++static inline void preempt_latency_stop(int val) { } ++#endif ++ ++static inline unsigned long get_preempt_disable_ip(struct task_struct *p) ++{ ++#ifdef CONFIG_DEBUG_PREEMPT ++ return p->preempt_disable_ip; ++#else ++ return 0; ++#endif ++} ++ ++/* ++ * Print scheduling while atomic bug: ++ */ ++static noinline void __schedule_bug(struct task_struct *prev) ++{ ++ /* Save this before calling printk(), since that will clobber it */ ++ unsigned long preempt_disable_ip = get_preempt_disable_ip(current); ++ ++ if (oops_in_progress) ++ return; ++ ++ printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", ++ prev->comm, prev->pid, preempt_count()); ++ ++ debug_show_held_locks(prev); ++ print_modules(); ++ if (irqs_disabled()) ++ print_irqtrace_events(prev); ++ if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) { ++ pr_err("Preemption disabled at:"); ++ print_ip_sym(KERN_ERR, preempt_disable_ip); ++ } ++ check_panic_on_warn("scheduling while atomic"); ++ ++ dump_stack(); ++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); ++} ++ ++/* ++ * Various schedule()-time debugging checks and statistics: ++ */ ++static inline void schedule_debug(struct task_struct *prev, bool preempt) ++{ ++#ifdef CONFIG_SCHED_STACK_END_CHECK ++ if (task_stack_end_corrupted(prev)) ++ panic("corrupted stack end detected inside scheduler\n"); ++ ++ if (task_scs_end_corrupted(prev)) ++ panic("corrupted shadow stack detected inside scheduler\n"); ++#endif ++ ++#ifdef CONFIG_DEBUG_ATOMIC_SLEEP ++ if (!preempt && READ_ONCE(prev->__state) && prev->non_block_count) { ++ printk(KERN_ERR "BUG: scheduling in a non-blocking section: %s/%d/%i\n", ++ prev->comm, prev->pid, prev->non_block_count); ++ dump_stack(); ++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); ++ } ++#endif ++ ++ if (unlikely(in_atomic_preempt_off())) { ++ __schedule_bug(prev); ++ preempt_count_set(PREEMPT_DISABLED); ++ } ++ rcu_sleep_check(); ++ SCHED_WARN_ON(ct_state() == CONTEXT_USER); ++ ++ profile_hit(SCHED_PROFILING, __builtin_return_address(0)); ++ ++ schedstat_inc(this_rq()->sched_count); ++} ++ ++#ifdef ALT_SCHED_DEBUG ++void alt_sched_debug(void) ++{ ++ printk(KERN_INFO "sched: pending: 0x%04lx, idle: 0x%04lx, sg_idle: 0x%04lx\n", ++ sched_rq_pending_mask.bits[0], ++ sched_idle_mask->bits[0], ++ sched_sg_idle_mask.bits[0]); ++} ++#else ++inline void alt_sched_debug(void) {} ++#endif ++ ++#ifdef CONFIG_SMP ++ ++#ifdef CONFIG_PREEMPT_RT ++#define SCHED_NR_MIGRATE_BREAK 8 ++#else ++#define SCHED_NR_MIGRATE_BREAK 32 ++#endif ++ ++const_debug unsigned int sysctl_sched_nr_migrate = SCHED_NR_MIGRATE_BREAK; ++ ++/* ++ * Migrate pending tasks in @rq to @dest_cpu ++ */ ++static inline int ++migrate_pending_tasks(struct rq *rq, struct rq *dest_rq, const int dest_cpu) ++{ ++ struct task_struct *p, *skip = rq->curr; ++ int nr_migrated = 0; ++ int nr_tries = min(rq->nr_running / 2, sysctl_sched_nr_migrate); ++ ++ /* WA to check rq->curr is still on rq */ ++ if (!task_on_rq_queued(skip)) ++ return 0; ++ ++ while (skip != rq->idle && nr_tries && ++ (p = sched_rq_next_task(skip, rq)) != rq->idle) { ++ skip = sched_rq_next_task(p, rq); ++ if (cpumask_test_cpu(dest_cpu, p->cpus_ptr)) { ++ __SCHED_DEQUEUE_TASK(p, rq, 0, ); ++ set_task_cpu(p, dest_cpu); ++ sched_task_sanity_check(p, dest_rq); ++ sched_mm_cid_migrate_to(dest_rq, p, cpu_of(rq)); ++ __SCHED_ENQUEUE_TASK(p, dest_rq, 0); ++ nr_migrated++; ++ } ++ nr_tries--; ++ } ++ ++ return nr_migrated; ++} ++ ++static inline int take_other_rq_tasks(struct rq *rq, int cpu) ++{ ++ struct cpumask *topo_mask, *end_mask; ++ ++ if (unlikely(!rq->online)) ++ return 0; ++ ++ if (cpumask_empty(&sched_rq_pending_mask)) ++ return 0; ++ ++ topo_mask = per_cpu(sched_cpu_topo_masks, cpu) + 1; ++ end_mask = per_cpu(sched_cpu_topo_end_mask, cpu); ++ do { ++ int i; ++ for_each_cpu_and(i, &sched_rq_pending_mask, topo_mask) { ++ int nr_migrated; ++ struct rq *src_rq; ++ ++ src_rq = cpu_rq(i); ++ if (!do_raw_spin_trylock(&src_rq->lock)) ++ continue; ++ spin_acquire(&src_rq->lock.dep_map, ++ SINGLE_DEPTH_NESTING, 1, _RET_IP_); ++ ++ if ((nr_migrated = migrate_pending_tasks(src_rq, rq, cpu))) { ++ src_rq->nr_running -= nr_migrated; ++ if (src_rq->nr_running < 2) ++ cpumask_clear_cpu(i, &sched_rq_pending_mask); ++ ++ spin_release(&src_rq->lock.dep_map, _RET_IP_); ++ do_raw_spin_unlock(&src_rq->lock); ++ ++ rq->nr_running += nr_migrated; ++ if (rq->nr_running > 1) ++ cpumask_set_cpu(cpu, &sched_rq_pending_mask); ++ ++ update_sched_preempt_mask(rq); ++ cpufreq_update_util(rq, 0); ++ ++ return 1; ++ } ++ ++ spin_release(&src_rq->lock.dep_map, _RET_IP_); ++ do_raw_spin_unlock(&src_rq->lock); ++ } ++ } while (++topo_mask < end_mask); ++ ++ return 0; ++} ++#endif ++ ++static inline void time_slice_expired(struct task_struct *p, struct rq *rq) ++{ ++ p->time_slice = sched_timeslice_ns; ++ ++ sched_task_renew(p, rq); ++ ++ if (SCHED_FIFO != p->policy && task_on_rq_queued(p)) ++ requeue_task(p, rq, task_sched_prio_idx(p, rq)); ++} ++ ++/* ++ * Timeslices below RESCHED_NS are considered as good as expired as there's no ++ * point rescheduling when there's so little time left. ++ */ ++static inline void check_curr(struct task_struct *p, struct rq *rq) ++{ ++ if (unlikely(rq->idle == p)) ++ return; ++ ++ update_curr(rq, p); ++ ++ if (p->time_slice < RESCHED_NS) ++ time_slice_expired(p, rq); ++} ++ ++static inline struct task_struct * ++choose_next_task(struct rq *rq, int cpu) ++{ ++ struct task_struct *next; ++ ++ if (unlikely(rq->skip)) { ++ next = rq_runnable_task(rq); ++ if (next == rq->idle) { ++#ifdef CONFIG_SMP ++ if (!take_other_rq_tasks(rq, cpu)) { ++#endif ++ rq->skip = NULL; ++ schedstat_inc(rq->sched_goidle); ++ return next; ++#ifdef CONFIG_SMP ++ } ++ next = rq_runnable_task(rq); ++#endif ++ } ++ rq->skip = NULL; ++#ifdef CONFIG_HIGH_RES_TIMERS ++ hrtick_start(rq, next->time_slice); ++#endif ++ return next; ++ } ++ ++ next = sched_rq_first_task(rq); ++ if (next == rq->idle) { ++#ifdef CONFIG_SMP ++ if (!take_other_rq_tasks(rq, cpu)) { ++#endif ++ schedstat_inc(rq->sched_goidle); ++ /*printk(KERN_INFO "sched: choose_next_task(%d) idle %px\n", cpu, next);*/ ++ return next; ++#ifdef CONFIG_SMP ++ } ++ next = sched_rq_first_task(rq); ++#endif ++ } ++#ifdef CONFIG_HIGH_RES_TIMERS ++ hrtick_start(rq, next->time_slice); ++#endif ++ /*printk(KERN_INFO "sched: choose_next_task(%d) next %px\n", cpu, next);*/ ++ return next; ++} ++ ++/* ++ * Constants for the sched_mode argument of __schedule(). ++ * ++ * The mode argument allows RT enabled kernels to differentiate a ++ * preemption from blocking on an 'sleeping' spin/rwlock. Note that ++ * SM_MASK_PREEMPT for !RT has all bits set, which allows the compiler to ++ * optimize the AND operation out and just check for zero. ++ */ ++#define SM_NONE 0x0 ++#define SM_PREEMPT 0x1 ++#define SM_RTLOCK_WAIT 0x2 ++ ++#ifndef CONFIG_PREEMPT_RT ++# define SM_MASK_PREEMPT (~0U) ++#else ++# define SM_MASK_PREEMPT SM_PREEMPT ++#endif ++ ++/* ++ * schedule() is the main scheduler function. ++ * ++ * The main means of driving the scheduler and thus entering this function are: ++ * ++ * 1. Explicit blocking: mutex, semaphore, waitqueue, etc. ++ * ++ * 2. TIF_NEED_RESCHED flag is checked on interrupt and userspace return ++ * paths. For example, see arch/x86/entry_64.S. ++ * ++ * To drive preemption between tasks, the scheduler sets the flag in timer ++ * interrupt handler scheduler_tick(). ++ * ++ * 3. Wakeups don't really cause entry into schedule(). They add a ++ * task to the run-queue and that's it. ++ * ++ * Now, if the new task added to the run-queue preempts the current ++ * task, then the wakeup sets TIF_NEED_RESCHED and schedule() gets ++ * called on the nearest possible occasion: ++ * ++ * - If the kernel is preemptible (CONFIG_PREEMPTION=y): ++ * ++ * - in syscall or exception context, at the next outmost ++ * preempt_enable(). (this might be as soon as the wake_up()'s ++ * spin_unlock()!) ++ * ++ * - in IRQ context, return from interrupt-handler to ++ * preemptible context ++ * ++ * - If the kernel is not preemptible (CONFIG_PREEMPTION is not set) ++ * then at the next: ++ * ++ * - cond_resched() call ++ * - explicit schedule() call ++ * - return from syscall or exception to user-space ++ * - return from interrupt-handler to user-space ++ * ++ * WARNING: must be called with preemption disabled! ++ */ ++static void __sched notrace __schedule(unsigned int sched_mode) ++{ ++ struct task_struct *prev, *next; ++ unsigned long *switch_count; ++ unsigned long prev_state; ++ struct rq *rq; ++ int cpu; ++ ++ cpu = smp_processor_id(); ++ rq = cpu_rq(cpu); ++ prev = rq->curr; ++ ++ schedule_debug(prev, !!sched_mode); ++ ++ /* by passing sched_feat(HRTICK) checking which Alt schedule FW doesn't support */ ++ hrtick_clear(rq); ++ ++ local_irq_disable(); ++ rcu_note_context_switch(!!sched_mode); ++ ++ /* ++ * Make sure that signal_pending_state()->signal_pending() below ++ * can't be reordered with __set_current_state(TASK_INTERRUPTIBLE) ++ * done by the caller to avoid the race with signal_wake_up(): ++ * ++ * __set_current_state(@state) signal_wake_up() ++ * schedule() set_tsk_thread_flag(p, TIF_SIGPENDING) ++ * wake_up_state(p, state) ++ * LOCK rq->lock LOCK p->pi_state ++ * smp_mb__after_spinlock() smp_mb__after_spinlock() ++ * if (signal_pending_state()) if (p->state & @state) ++ * ++ * Also, the membarrier system call requires a full memory barrier ++ * after coming from user-space, before storing to rq->curr. ++ */ ++ raw_spin_lock(&rq->lock); ++ smp_mb__after_spinlock(); ++ ++ update_rq_clock(rq); ++ ++ switch_count = &prev->nivcsw; ++ /* ++ * We must load prev->state once (task_struct::state is volatile), such ++ * that we form a control dependency vs deactivate_task() below. ++ */ ++ prev_state = READ_ONCE(prev->__state); ++ if (!(sched_mode & SM_MASK_PREEMPT) && prev_state) { ++ if (signal_pending_state(prev_state, prev)) { ++ WRITE_ONCE(prev->__state, TASK_RUNNING); ++ } else { ++ prev->sched_contributes_to_load = ++ (prev_state & TASK_UNINTERRUPTIBLE) && ++ !(prev_state & TASK_NOLOAD) && ++ !(prev_state & TASK_FROZEN); ++ ++ if (prev->sched_contributes_to_load) ++ rq->nr_uninterruptible++; ++ ++ /* ++ * __schedule() ttwu() ++ * prev_state = prev->state; if (p->on_rq && ...) ++ * if (prev_state) goto out; ++ * p->on_rq = 0; smp_acquire__after_ctrl_dep(); ++ * p->state = TASK_WAKING ++ * ++ * Where __schedule() and ttwu() have matching control dependencies. ++ * ++ * After this, schedule() must not care about p->state any more. ++ */ ++ sched_task_deactivate(prev, rq); ++ deactivate_task(prev, rq); ++ ++ if (prev->in_iowait) { ++ atomic_inc(&rq->nr_iowait); ++ delayacct_blkio_start(); ++ } ++ } ++ switch_count = &prev->nvcsw; ++ } ++ ++ check_curr(prev, rq); ++ ++ next = choose_next_task(rq, cpu); ++ clear_tsk_need_resched(prev); ++ clear_preempt_need_resched(); ++#ifdef CONFIG_SCHED_DEBUG ++ rq->last_seen_need_resched_ns = 0; ++#endif ++ ++ if (likely(prev != next)) { ++#ifdef CONFIG_SCHED_BMQ ++ rq->last_ts_switch = rq->clock; ++#endif ++ next->last_ran = rq->clock_task; ++ ++ /*printk(KERN_INFO "sched: %px -> %px\n", prev, next);*/ ++ rq->nr_switches++; ++ /* ++ * RCU users of rcu_dereference(rq->curr) may not see ++ * changes to task_struct made by pick_next_task(). ++ */ ++ RCU_INIT_POINTER(rq->curr, next); ++ /* ++ * The membarrier system call requires each architecture ++ * to have a full memory barrier after updating ++ * rq->curr, before returning to user-space. ++ * ++ * Here are the schemes providing that barrier on the ++ * various architectures: ++ * - mm ? switch_mm() : mmdrop() for x86, s390, sparc, PowerPC. ++ * switch_mm() rely on membarrier_arch_switch_mm() on PowerPC. ++ * - finish_lock_switch() for weakly-ordered ++ * architectures where spin_unlock is a full barrier, ++ * - switch_to() for arm64 (weakly-ordered, spin_unlock ++ * is a RELEASE barrier), ++ */ ++ ++*switch_count; ++ ++ trace_sched_switch(sched_mode & SM_MASK_PREEMPT, prev, next, prev_state); ++ ++ /* Also unlocks the rq: */ ++ rq = context_switch(rq, prev, next); ++ ++ cpu = cpu_of(rq); ++ } else { ++ __balance_callbacks(rq); ++ raw_spin_unlock_irq(&rq->lock); ++ } ++ ++#ifdef CONFIG_SCHED_SMT ++ sg_balance(rq, cpu); ++#endif ++} ++ ++void __noreturn do_task_dead(void) ++{ ++ /* Causes final put_task_struct in finish_task_switch(): */ ++ set_special_state(TASK_DEAD); ++ ++ /* Tell freezer to ignore us: */ ++ current->flags |= PF_NOFREEZE; ++ ++ __schedule(SM_NONE); ++ BUG(); ++ ++ /* Avoid "noreturn function does return" - but don't continue if BUG() is a NOP: */ ++ for (;;) ++ cpu_relax(); ++} ++ ++static inline void sched_submit_work(struct task_struct *tsk) ++{ ++ static DEFINE_WAIT_OVERRIDE_MAP(sched_map, LD_WAIT_CONFIG); ++ unsigned int task_flags; ++ ++ /* ++ * Establish LD_WAIT_CONFIG context to ensure none of the code called ++ * will use a blocking primitive -- which would lead to recursion. ++ */ ++ lock_map_acquire_try(&sched_map); ++ ++ task_flags = tsk->flags; ++ /* ++ * If a worker goes to sleep, notify and ask workqueue whether it ++ * wants to wake up a task to maintain concurrency. ++ */ ++ if (task_flags & PF_WQ_WORKER) ++ wq_worker_sleeping(tsk); ++ else if (task_flags & PF_IO_WORKER) ++ io_wq_worker_sleeping(tsk); ++ ++ /* ++ * spinlock and rwlock must not flush block requests. This will ++ * deadlock if the callback attempts to acquire a lock which is ++ * already acquired. ++ */ ++ SCHED_WARN_ON(current->__state & TASK_RTLOCK_WAIT); ++ ++ /* ++ * If we are going to sleep and we have plugged IO queued, ++ * make sure to submit it to avoid deadlocks. ++ */ ++ blk_flush_plug(tsk->plug, true); ++ ++ lock_map_release(&sched_map); ++} ++ ++static void sched_update_worker(struct task_struct *tsk) ++{ ++ if (tsk->flags & (PF_WQ_WORKER | PF_IO_WORKER)) { ++ if (tsk->flags & PF_WQ_WORKER) ++ wq_worker_running(tsk); ++ else ++ io_wq_worker_running(tsk); ++ } ++} ++ ++static __always_inline void __schedule_loop(unsigned int sched_mode) ++{ ++ do { ++ preempt_disable(); ++ __schedule(sched_mode); ++ sched_preempt_enable_no_resched(); ++ } while (need_resched()); ++} ++ ++asmlinkage __visible void __sched schedule(void) ++{ ++ struct task_struct *tsk = current; ++ ++#ifdef CONFIG_RT_MUTEXE ++ lockdep_assert(!tsk->sched_rt_mutex); ++#endif ++ ++ if (!task_is_running(tsk)) ++ sched_submit_work(tsk); ++ __schedule_loop(SM_NONE); ++ sched_update_worker(tsk); ++} ++EXPORT_SYMBOL(schedule); ++ ++/* ++ * synchronize_rcu_tasks() makes sure that no task is stuck in preempted ++ * state (have scheduled out non-voluntarily) by making sure that all ++ * tasks have either left the run queue or have gone into user space. ++ * As idle tasks do not do either, they must not ever be preempted ++ * (schedule out non-voluntarily). ++ * ++ * schedule_idle() is similar to schedule_preempt_disable() except that it ++ * never enables preemption because it does not call sched_submit_work(). ++ */ ++void __sched schedule_idle(void) ++{ ++ /* ++ * As this skips calling sched_submit_work(), which the idle task does ++ * regardless because that function is a nop when the task is in a ++ * TASK_RUNNING state, make sure this isn't used someplace that the ++ * current task can be in any other state. Note, idle is always in the ++ * TASK_RUNNING state. ++ */ ++ WARN_ON_ONCE(current->__state); ++ do { ++ __schedule(SM_NONE); ++ } while (need_resched()); ++} ++ ++#if defined(CONFIG_CONTEXT_TRACKING_USER) && !defined(CONFIG_HAVE_CONTEXT_TRACKING_USER_OFFSTACK) ++asmlinkage __visible void __sched schedule_user(void) ++{ ++ /* ++ * If we come here after a random call to set_need_resched(), ++ * or we have been woken up remotely but the IPI has not yet arrived, ++ * we haven't yet exited the RCU idle mode. Do it here manually until ++ * we find a better solution. ++ * ++ * NB: There are buggy callers of this function. Ideally we ++ * should warn if prev_state != CONTEXT_USER, but that will trigger ++ * too frequently to make sense yet. ++ */ ++ enum ctx_state prev_state = exception_enter(); ++ schedule(); ++ exception_exit(prev_state); ++} ++#endif ++ ++/** ++ * schedule_preempt_disabled - called with preemption disabled ++ * ++ * Returns with preemption disabled. Note: preempt_count must be 1 ++ */ ++void __sched schedule_preempt_disabled(void) ++{ ++ sched_preempt_enable_no_resched(); ++ schedule(); ++ preempt_disable(); ++} ++ ++#ifdef CONFIG_PREEMPT_RT ++void __sched notrace schedule_rtlock(void) ++{ ++ __schedule_loop(SM_RTLOCK_WAIT); ++} ++NOKPROBE_SYMBOL(schedule_rtlock); ++#endif ++ ++static void __sched notrace preempt_schedule_common(void) ++{ ++ do { ++ /* ++ * Because the function tracer can trace preempt_count_sub() ++ * and it also uses preempt_enable/disable_notrace(), if ++ * NEED_RESCHED is set, the preempt_enable_notrace() called ++ * by the function tracer will call this function again and ++ * cause infinite recursion. ++ * ++ * Preemption must be disabled here before the function ++ * tracer can trace. Break up preempt_disable() into two ++ * calls. One to disable preemption without fear of being ++ * traced. The other to still record the preemption latency, ++ * which can also be traced by the function tracer. ++ */ ++ preempt_disable_notrace(); ++ preempt_latency_start(1); ++ __schedule(SM_PREEMPT); ++ preempt_latency_stop(1); ++ preempt_enable_no_resched_notrace(); ++ ++ /* ++ * Check again in case we missed a preemption opportunity ++ * between schedule and now. ++ */ ++ } while (need_resched()); ++} ++ ++#ifdef CONFIG_PREEMPTION ++/* ++ * This is the entry point to schedule() from in-kernel preemption ++ * off of preempt_enable. ++ */ ++asmlinkage __visible void __sched notrace preempt_schedule(void) ++{ ++ /* ++ * If there is a non-zero preempt_count or interrupts are disabled, ++ * we do not want to preempt the current task. Just return.. ++ */ ++ if (likely(!preemptible())) ++ return; ++ ++ preempt_schedule_common(); ++} ++NOKPROBE_SYMBOL(preempt_schedule); ++EXPORT_SYMBOL(preempt_schedule); ++ ++#ifdef CONFIG_PREEMPT_DYNAMIC ++#if defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) ++#ifndef preempt_schedule_dynamic_enabled ++#define preempt_schedule_dynamic_enabled preempt_schedule ++#define preempt_schedule_dynamic_disabled NULL ++#endif ++DEFINE_STATIC_CALL(preempt_schedule, preempt_schedule_dynamic_enabled); ++EXPORT_STATIC_CALL_TRAMP(preempt_schedule); ++#elif defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) ++static DEFINE_STATIC_KEY_TRUE(sk_dynamic_preempt_schedule); ++void __sched notrace dynamic_preempt_schedule(void) ++{ ++ if (!static_branch_unlikely(&sk_dynamic_preempt_schedule)) ++ return; ++ preempt_schedule(); ++} ++NOKPROBE_SYMBOL(dynamic_preempt_schedule); ++EXPORT_SYMBOL(dynamic_preempt_schedule); ++#endif ++#endif ++ ++/** ++ * preempt_schedule_notrace - preempt_schedule called by tracing ++ * ++ * The tracing infrastructure uses preempt_enable_notrace to prevent ++ * recursion and tracing preempt enabling caused by the tracing ++ * infrastructure itself. But as tracing can happen in areas coming ++ * from userspace or just about to enter userspace, a preempt enable ++ * can occur before user_exit() is called. This will cause the scheduler ++ * to be called when the system is still in usermode. ++ * ++ * To prevent this, the preempt_enable_notrace will use this function ++ * instead of preempt_schedule() to exit user context if needed before ++ * calling the scheduler. ++ */ ++asmlinkage __visible void __sched notrace preempt_schedule_notrace(void) ++{ ++ enum ctx_state prev_ctx; ++ ++ if (likely(!preemptible())) ++ return; ++ ++ do { ++ /* ++ * Because the function tracer can trace preempt_count_sub() ++ * and it also uses preempt_enable/disable_notrace(), if ++ * NEED_RESCHED is set, the preempt_enable_notrace() called ++ * by the function tracer will call this function again and ++ * cause infinite recursion. ++ * ++ * Preemption must be disabled here before the function ++ * tracer can trace. Break up preempt_disable() into two ++ * calls. One to disable preemption without fear of being ++ * traced. The other to still record the preemption latency, ++ * which can also be traced by the function tracer. ++ */ ++ preempt_disable_notrace(); ++ preempt_latency_start(1); ++ /* ++ * Needs preempt disabled in case user_exit() is traced ++ * and the tracer calls preempt_enable_notrace() causing ++ * an infinite recursion. ++ */ ++ prev_ctx = exception_enter(); ++ __schedule(SM_PREEMPT); ++ exception_exit(prev_ctx); ++ ++ preempt_latency_stop(1); ++ preempt_enable_no_resched_notrace(); ++ } while (need_resched()); ++} ++EXPORT_SYMBOL_GPL(preempt_schedule_notrace); ++ ++#ifdef CONFIG_PREEMPT_DYNAMIC ++#if defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) ++#ifndef preempt_schedule_notrace_dynamic_enabled ++#define preempt_schedule_notrace_dynamic_enabled preempt_schedule_notrace ++#define preempt_schedule_notrace_dynamic_disabled NULL ++#endif ++DEFINE_STATIC_CALL(preempt_schedule_notrace, preempt_schedule_notrace_dynamic_enabled); ++EXPORT_STATIC_CALL_TRAMP(preempt_schedule_notrace); ++#elif defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) ++static DEFINE_STATIC_KEY_TRUE(sk_dynamic_preempt_schedule_notrace); ++void __sched notrace dynamic_preempt_schedule_notrace(void) ++{ ++ if (!static_branch_unlikely(&sk_dynamic_preempt_schedule_notrace)) ++ return; ++ preempt_schedule_notrace(); ++} ++NOKPROBE_SYMBOL(dynamic_preempt_schedule_notrace); ++EXPORT_SYMBOL(dynamic_preempt_schedule_notrace); ++#endif ++#endif ++ ++#endif /* CONFIG_PREEMPTION */ ++ ++/* ++ * This is the entry point to schedule() from kernel preemption ++ * off of irq context. ++ * Note, that this is called and return with irqs disabled. This will ++ * protect us against recursive calling from irq. ++ */ ++asmlinkage __visible void __sched preempt_schedule_irq(void) ++{ ++ enum ctx_state prev_state; ++ ++ /* Catch callers which need to be fixed */ ++ BUG_ON(preempt_count() || !irqs_disabled()); ++ ++ prev_state = exception_enter(); ++ ++ do { ++ preempt_disable(); ++ local_irq_enable(); ++ __schedule(SM_PREEMPT); ++ local_irq_disable(); ++ sched_preempt_enable_no_resched(); ++ } while (need_resched()); ++ ++ exception_exit(prev_state); ++} ++ ++int default_wake_function(wait_queue_entry_t *curr, unsigned mode, int wake_flags, ++ void *key) ++{ ++ WARN_ON_ONCE(IS_ENABLED(CONFIG_SCHED_DEBUG) && wake_flags & ~(WF_SYNC|WF_CURRENT_CPU)); ++ return try_to_wake_up(curr->private, mode, wake_flags); ++} ++EXPORT_SYMBOL(default_wake_function); ++ ++static inline void check_task_changed(struct task_struct *p, struct rq *rq) ++{ ++ /* Trigger resched if task sched_prio has been modified. */ ++ if (task_on_rq_queued(p)) { ++ int idx; ++ ++ update_rq_clock(rq); ++ idx = task_sched_prio_idx(p, rq); ++ if (idx != p->sq_idx) { ++ requeue_task(p, rq, idx); ++ wakeup_preempt(rq); ++ } ++ } ++} ++ ++static void __setscheduler_prio(struct task_struct *p, int prio) ++{ ++ p->prio = prio; ++} ++ ++#ifdef CONFIG_RT_MUTEXES ++ ++/* ++ * Would be more useful with typeof()/auto_type but they don't mix with ++ * bit-fields. Since it's a local thing, use int. Keep the generic sounding ++ * name such that if someone were to implement this function we get to compare ++ * notes. ++ */ ++#define fetch_and_set(x, v) ({ int _x = (x); (x) = (v); _x; }) ++ ++void rt_mutex_pre_schedule(void) ++{ ++ lockdep_assert(!fetch_and_set(current->sched_rt_mutex, 1)); ++ sched_submit_work(current); ++} ++ ++void rt_mutex_schedule(void) ++{ ++ lockdep_assert(current->sched_rt_mutex); ++ __schedule_loop(SM_NONE); ++} ++ ++void rt_mutex_post_schedule(void) ++{ ++ sched_update_worker(current); ++ lockdep_assert(fetch_and_set(current->sched_rt_mutex, 0)); ++} ++ ++static inline int __rt_effective_prio(struct task_struct *pi_task, int prio) ++{ ++ if (pi_task) ++ prio = min(prio, pi_task->prio); ++ ++ return prio; ++} ++ ++static inline int rt_effective_prio(struct task_struct *p, int prio) ++{ ++ struct task_struct *pi_task = rt_mutex_get_top_task(p); ++ ++ return __rt_effective_prio(pi_task, prio); ++} ++ ++/* ++ * rt_mutex_setprio - set the current priority of a task ++ * @p: task to boost ++ * @pi_task: donor task ++ * ++ * This function changes the 'effective' priority of a task. It does ++ * not touch ->normal_prio like __setscheduler(). ++ * ++ * Used by the rt_mutex code to implement priority inheritance ++ * logic. Call site only calls if the priority of the task changed. ++ */ ++void rt_mutex_setprio(struct task_struct *p, struct task_struct *pi_task) ++{ ++ int prio; ++ struct rq *rq; ++ raw_spinlock_t *lock; ++ ++ /* XXX used to be waiter->prio, not waiter->task->prio */ ++ prio = __rt_effective_prio(pi_task, p->normal_prio); ++ ++ /* ++ * If nothing changed; bail early. ++ */ ++ if (p->pi_top_task == pi_task && prio == p->prio) ++ return; ++ ++ rq = __task_access_lock(p, &lock); ++ /* ++ * Set under pi_lock && rq->lock, such that the value can be used under ++ * either lock. ++ * ++ * Note that there is loads of tricky to make this pointer cache work ++ * right. rt_mutex_slowunlock()+rt_mutex_postunlock() work together to ++ * ensure a task is de-boosted (pi_task is set to NULL) before the ++ * task is allowed to run again (and can exit). This ensures the pointer ++ * points to a blocked task -- which guarantees the task is present. ++ */ ++ p->pi_top_task = pi_task; ++ ++ /* ++ * For FIFO/RR we only need to set prio, if that matches we're done. ++ */ ++ if (prio == p->prio) ++ goto out_unlock; ++ ++ /* ++ * Idle task boosting is a nono in general. There is one ++ * exception, when PREEMPT_RT and NOHZ is active: ++ * ++ * The idle task calls get_next_timer_interrupt() and holds ++ * the timer wheel base->lock on the CPU and another CPU wants ++ * to access the timer (probably to cancel it). We can safely ++ * ignore the boosting request, as the idle CPU runs this code ++ * with interrupts disabled and will complete the lock ++ * protected section without being interrupted. So there is no ++ * real need to boost. ++ */ ++ if (unlikely(p == rq->idle)) { ++ WARN_ON(p != rq->curr); ++ WARN_ON(p->pi_blocked_on); ++ goto out_unlock; ++ } ++ ++ trace_sched_pi_setprio(p, pi_task); ++ ++ __setscheduler_prio(p, prio); ++ ++ check_task_changed(p, rq); ++out_unlock: ++ /* Avoid rq from going away on us: */ ++ preempt_disable(); ++ ++ __balance_callbacks(rq); ++ __task_access_unlock(p, lock); ++ ++ preempt_enable(); ++} ++#else ++static inline int rt_effective_prio(struct task_struct *p, int prio) ++{ ++ return prio; ++} ++#endif ++ ++void set_user_nice(struct task_struct *p, long nice) ++{ ++ unsigned long flags; ++ struct rq *rq; ++ raw_spinlock_t *lock; ++ ++ if (task_nice(p) == nice || nice < MIN_NICE || nice > MAX_NICE) ++ return; ++ /* ++ * We have to be careful, if called from sys_setpriority(), ++ * the task might be in the middle of scheduling on another CPU. ++ */ ++ raw_spin_lock_irqsave(&p->pi_lock, flags); ++ rq = __task_access_lock(p, &lock); ++ ++ p->static_prio = NICE_TO_PRIO(nice); ++ /* ++ * The RT priorities are set via sched_setscheduler(), but we still ++ * allow the 'normal' nice value to be set - but as expected ++ * it won't have any effect on scheduling until the task is ++ * not SCHED_NORMAL/SCHED_BATCH: ++ */ ++ if (task_has_rt_policy(p)) ++ goto out_unlock; ++ ++ p->prio = effective_prio(p); ++ ++ check_task_changed(p, rq); ++out_unlock: ++ __task_access_unlock(p, lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); ++} ++EXPORT_SYMBOL(set_user_nice); ++ ++/* ++ * is_nice_reduction - check if nice value is an actual reduction ++ * ++ * Similar to can_nice() but does not perform a capability check. ++ * ++ * @p: task ++ * @nice: nice value ++ */ ++static bool is_nice_reduction(const struct task_struct *p, const int nice) ++{ ++ /* Convert nice value [19,-20] to rlimit style value [1,40]: */ ++ int nice_rlim = nice_to_rlimit(nice); ++ ++ return (nice_rlim <= task_rlimit(p, RLIMIT_NICE)); ++} ++ ++/* ++ * can_nice - check if a task can reduce its nice value ++ * @p: task ++ * @nice: nice value ++ */ ++int can_nice(const struct task_struct *p, const int nice) ++{ ++ return is_nice_reduction(p, nice) || capable(CAP_SYS_NICE); ++} ++ ++#ifdef __ARCH_WANT_SYS_NICE ++ ++/* ++ * sys_nice - change the priority of the current process. ++ * @increment: priority increment ++ * ++ * sys_setpriority is a more generic, but much slower function that ++ * does similar things. ++ */ ++SYSCALL_DEFINE1(nice, int, increment) ++{ ++ long nice, retval; ++ ++ /* ++ * Setpriority might change our priority at the same moment. ++ * We don't have to worry. Conceptually one call occurs first ++ * and we have a single winner. ++ */ ++ ++ increment = clamp(increment, -NICE_WIDTH, NICE_WIDTH); ++ nice = task_nice(current) + increment; ++ ++ nice = clamp_val(nice, MIN_NICE, MAX_NICE); ++ if (increment < 0 && !can_nice(current, nice)) ++ return -EPERM; ++ ++ retval = security_task_setnice(current, nice); ++ if (retval) ++ return retval; ++ ++ set_user_nice(current, nice); ++ return 0; ++} ++ ++#endif ++ ++/** ++ * task_prio - return the priority value of a given task. ++ * @p: the task in question. ++ * ++ * Return: The priority value as seen by users in /proc. ++ * ++ * sched policy return value kernel prio user prio/nice ++ * ++ * (BMQ)normal, batch, idle[0 ... 53] [100 ... 139] 0/[-20 ... 19]/[-7 ... 7] ++ * (PDS)normal, batch, idle[0 ... 39] 100 0/[-20 ... 19] ++ * fifo, rr [-1 ... -100] [99 ... 0] [0 ... 99] ++ */ ++int task_prio(const struct task_struct *p) ++{ ++ return (p->prio < MAX_RT_PRIO) ? p->prio - MAX_RT_PRIO : ++ task_sched_prio_normal(p, task_rq(p)); ++} ++ ++/** ++ * idle_cpu - is a given CPU idle currently? ++ * @cpu: the processor in question. ++ * ++ * Return: 1 if the CPU is currently idle. 0 otherwise. ++ */ ++int idle_cpu(int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ ++ if (rq->curr != rq->idle) ++ return 0; ++ ++ if (rq->nr_running) ++ return 0; ++ ++#ifdef CONFIG_SMP ++ if (rq->ttwu_pending) ++ return 0; ++#endif ++ ++ return 1; ++} ++ ++/** ++ * idle_task - return the idle task for a given CPU. ++ * @cpu: the processor in question. ++ * ++ * Return: The idle task for the cpu @cpu. ++ */ ++struct task_struct *idle_task(int cpu) ++{ ++ return cpu_rq(cpu)->idle; ++} ++ ++/** ++ * find_process_by_pid - find a process with a matching PID value. ++ * @pid: the pid in question. ++ * ++ * The task of @pid, if found. %NULL otherwise. ++ */ ++static inline struct task_struct *find_process_by_pid(pid_t pid) ++{ ++ return pid ? find_task_by_vpid(pid) : current; ++} ++ ++static struct task_struct *find_get_task(pid_t pid) ++{ ++ struct task_struct *p; ++ guard(rcu)(); ++ ++ p = find_process_by_pid(pid); ++ if (likely(p)) ++ get_task_struct(p); ++ ++ return p; ++} ++ ++DEFINE_CLASS(find_get_task, struct task_struct *, if (_T) put_task_struct(_T), ++ find_get_task(pid), pid_t pid) ++ ++/* ++ * sched_setparam() passes in -1 for its policy, to let the functions ++ * it calls know not to change it. ++ */ ++#define SETPARAM_POLICY -1 ++ ++static void __setscheduler_params(struct task_struct *p, ++ const struct sched_attr *attr) ++{ ++ int policy = attr->sched_policy; ++ ++ if (policy == SETPARAM_POLICY) ++ policy = p->policy; ++ ++ p->policy = policy; ++ ++ /* ++ * allow normal nice value to be set, but will not have any ++ * effect on scheduling until the task not SCHED_NORMAL/ ++ * SCHED_BATCH ++ */ ++ p->static_prio = NICE_TO_PRIO(attr->sched_nice); ++ ++ /* ++ * __sched_setscheduler() ensures attr->sched_priority == 0 when ++ * !rt_policy. Always setting this ensures that things like ++ * getparam()/getattr() don't report silly values for !rt tasks. ++ */ ++ p->rt_priority = attr->sched_priority; ++ p->normal_prio = normal_prio(p); ++} ++ ++/* ++ * check the target process has a UID that matches the current process's ++ */ ++static bool check_same_owner(struct task_struct *p) ++{ ++ const struct cred *cred = current_cred(), *pcred; ++ guard(rcu)(); ++ ++ pcred = __task_cred(p); ++ return (uid_eq(cred->euid, pcred->euid) || ++ uid_eq(cred->euid, pcred->uid)); ++} ++ ++/* ++ * Allow unprivileged RT tasks to decrease priority. ++ * Only issue a capable test if needed and only once to avoid an audit ++ * event on permitted non-privileged operations: ++ */ ++static int user_check_sched_setscheduler(struct task_struct *p, ++ const struct sched_attr *attr, ++ int policy, int reset_on_fork) ++{ ++ if (rt_policy(policy)) { ++ unsigned long rlim_rtprio = task_rlimit(p, RLIMIT_RTPRIO); ++ ++ /* Can't set/change the rt policy: */ ++ if (policy != p->policy && !rlim_rtprio) ++ goto req_priv; ++ ++ /* Can't increase priority: */ ++ if (attr->sched_priority > p->rt_priority && ++ attr->sched_priority > rlim_rtprio) ++ goto req_priv; ++ } ++ ++ /* Can't change other user's priorities: */ ++ if (!check_same_owner(p)) ++ goto req_priv; ++ ++ /* Normal users shall not reset the sched_reset_on_fork flag: */ ++ if (p->sched_reset_on_fork && !reset_on_fork) ++ goto req_priv; ++ ++ return 0; ++ ++req_priv: ++ if (!capable(CAP_SYS_NICE)) ++ return -EPERM; ++ ++ return 0; ++} ++ ++static int __sched_setscheduler(struct task_struct *p, ++ const struct sched_attr *attr, ++ bool user, bool pi) ++{ ++ const struct sched_attr dl_squash_attr = { ++ .size = sizeof(struct sched_attr), ++ .sched_policy = SCHED_FIFO, ++ .sched_nice = 0, ++ .sched_priority = 99, ++ }; ++ int oldpolicy = -1, policy = attr->sched_policy; ++ int retval, newprio; ++ struct balance_callback *head; ++ unsigned long flags; ++ struct rq *rq; ++ int reset_on_fork; ++ raw_spinlock_t *lock; ++ ++ /* The pi code expects interrupts enabled */ ++ BUG_ON(pi && in_interrupt()); ++ ++ /* ++ * Alt schedule FW supports SCHED_DEADLINE by squash it as prio 0 SCHED_FIFO ++ */ ++ if (unlikely(SCHED_DEADLINE == policy)) { ++ attr = &dl_squash_attr; ++ policy = attr->sched_policy; ++ } ++recheck: ++ /* Double check policy once rq lock held */ ++ if (policy < 0) { ++ reset_on_fork = p->sched_reset_on_fork; ++ policy = oldpolicy = p->policy; ++ } else { ++ reset_on_fork = !!(attr->sched_flags & SCHED_RESET_ON_FORK); ++ ++ if (policy > SCHED_IDLE) ++ return -EINVAL; ++ } ++ ++ if (attr->sched_flags & ~(SCHED_FLAG_ALL)) ++ return -EINVAL; ++ ++ /* ++ * Valid priorities for SCHED_FIFO and SCHED_RR are ++ * 1..MAX_RT_PRIO-1, valid priority for SCHED_NORMAL and ++ * SCHED_BATCH and SCHED_IDLE is 0. ++ */ ++ if (attr->sched_priority < 0 || ++ (p->mm && attr->sched_priority > MAX_RT_PRIO - 1) || ++ (!p->mm && attr->sched_priority > MAX_RT_PRIO - 1)) ++ return -EINVAL; ++ if ((SCHED_RR == policy || SCHED_FIFO == policy) != ++ (attr->sched_priority != 0)) ++ return -EINVAL; ++ ++ if (user) { ++ retval = user_check_sched_setscheduler(p, attr, policy, reset_on_fork); ++ if (retval) ++ return retval; ++ ++ retval = security_task_setscheduler(p); ++ if (retval) ++ return retval; ++ } ++ ++ /* ++ * Make sure no PI-waiters arrive (or leave) while we are ++ * changing the priority of the task: ++ */ ++ raw_spin_lock_irqsave(&p->pi_lock, flags); ++ ++ /* ++ * To be able to change p->policy safely, task_access_lock() ++ * must be called. ++ * IF use task_access_lock() here: ++ * For the task p which is not running, reading rq->stop is ++ * racy but acceptable as ->stop doesn't change much. ++ * An enhancemnet can be made to read rq->stop saftly. ++ */ ++ rq = __task_access_lock(p, &lock); ++ ++ /* ++ * Changing the policy of the stop threads its a very bad idea ++ */ ++ if (p == rq->stop) { ++ retval = -EINVAL; ++ goto unlock; ++ } ++ ++ /* ++ * If not changing anything there's no need to proceed further: ++ */ ++ if (unlikely(policy == p->policy)) { ++ if (rt_policy(policy) && attr->sched_priority != p->rt_priority) ++ goto change; ++ if (!rt_policy(policy) && ++ NICE_TO_PRIO(attr->sched_nice) != p->static_prio) ++ goto change; ++ ++ p->sched_reset_on_fork = reset_on_fork; ++ retval = 0; ++ goto unlock; ++ } ++change: ++ ++ /* Re-check policy now with rq lock held */ ++ if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { ++ policy = oldpolicy = -1; ++ __task_access_unlock(p, lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); ++ goto recheck; ++ } ++ ++ p->sched_reset_on_fork = reset_on_fork; ++ ++ newprio = __normal_prio(policy, attr->sched_priority, NICE_TO_PRIO(attr->sched_nice)); ++ if (pi) { ++ /* ++ * Take priority boosted tasks into account. If the new ++ * effective priority is unchanged, we just store the new ++ * normal parameters and do not touch the scheduler class and ++ * the runqueue. This will be done when the task deboost ++ * itself. ++ */ ++ newprio = rt_effective_prio(p, newprio); ++ } ++ ++ if (!(attr->sched_flags & SCHED_FLAG_KEEP_PARAMS)) { ++ __setscheduler_params(p, attr); ++ __setscheduler_prio(p, newprio); ++ } ++ ++ check_task_changed(p, rq); ++ ++ /* Avoid rq from going away on us: */ ++ preempt_disable(); ++ head = splice_balance_callbacks(rq); ++ __task_access_unlock(p, lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); ++ ++ if (pi) ++ rt_mutex_adjust_pi(p); ++ ++ /* Run balance callbacks after we've adjusted the PI chain: */ ++ balance_callbacks(rq, head); ++ preempt_enable(); ++ ++ return 0; ++ ++unlock: ++ __task_access_unlock(p, lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); ++ return retval; ++} ++ ++static int _sched_setscheduler(struct task_struct *p, int policy, ++ const struct sched_param *param, bool check) ++{ ++ struct sched_attr attr = { ++ .sched_policy = policy, ++ .sched_priority = param->sched_priority, ++ .sched_nice = PRIO_TO_NICE(p->static_prio), ++ }; ++ ++ /* Fixup the legacy SCHED_RESET_ON_FORK hack. */ ++ if ((policy != SETPARAM_POLICY) && (policy & SCHED_RESET_ON_FORK)) { ++ attr.sched_flags |= SCHED_FLAG_RESET_ON_FORK; ++ policy &= ~SCHED_RESET_ON_FORK; ++ attr.sched_policy = policy; ++ } ++ ++ return __sched_setscheduler(p, &attr, check, true); ++} ++ ++/** ++ * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. ++ * @p: the task in question. ++ * @policy: new policy. ++ * @param: structure containing the new RT priority. ++ * ++ * Use sched_set_fifo(), read its comment. ++ * ++ * Return: 0 on success. An error code otherwise. ++ * ++ * NOTE that the task may be already dead. ++ */ ++int sched_setscheduler(struct task_struct *p, int policy, ++ const struct sched_param *param) ++{ ++ return _sched_setscheduler(p, policy, param, true); ++} ++ ++int sched_setattr(struct task_struct *p, const struct sched_attr *attr) ++{ ++ return __sched_setscheduler(p, attr, true, true); ++} ++ ++int sched_setattr_nocheck(struct task_struct *p, const struct sched_attr *attr) ++{ ++ return __sched_setscheduler(p, attr, false, true); ++} ++EXPORT_SYMBOL_GPL(sched_setattr_nocheck); ++ ++/** ++ * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. ++ * @p: the task in question. ++ * @policy: new policy. ++ * @param: structure containing the new RT priority. ++ * ++ * Just like sched_setscheduler, only don't bother checking if the ++ * current context has permission. For example, this is needed in ++ * stop_machine(): we create temporary high priority worker threads, ++ * but our caller might not have that capability. ++ * ++ * Return: 0 on success. An error code otherwise. ++ */ ++int sched_setscheduler_nocheck(struct task_struct *p, int policy, ++ const struct sched_param *param) ++{ ++ return _sched_setscheduler(p, policy, param, false); ++} ++ ++/* ++ * SCHED_FIFO is a broken scheduler model; that is, it is fundamentally ++ * incapable of resource management, which is the one thing an OS really should ++ * be doing. ++ * ++ * This is of course the reason it is limited to privileged users only. ++ * ++ * Worse still; it is fundamentally impossible to compose static priority ++ * workloads. You cannot take two correctly working static prio workloads ++ * and smash them together and still expect them to work. ++ * ++ * For this reason 'all' FIFO tasks the kernel creates are basically at: ++ * ++ * MAX_RT_PRIO / 2 ++ * ++ * The administrator _MUST_ configure the system, the kernel simply doesn't ++ * know enough information to make a sensible choice. ++ */ ++void sched_set_fifo(struct task_struct *p) ++{ ++ struct sched_param sp = { .sched_priority = MAX_RT_PRIO / 2 }; ++ WARN_ON_ONCE(sched_setscheduler_nocheck(p, SCHED_FIFO, &sp) != 0); ++} ++EXPORT_SYMBOL_GPL(sched_set_fifo); ++ ++/* ++ * For when you don't much care about FIFO, but want to be above SCHED_NORMAL. ++ */ ++void sched_set_fifo_low(struct task_struct *p) ++{ ++ struct sched_param sp = { .sched_priority = 1 }; ++ WARN_ON_ONCE(sched_setscheduler_nocheck(p, SCHED_FIFO, &sp) != 0); ++} ++EXPORT_SYMBOL_GPL(sched_set_fifo_low); ++ ++void sched_set_normal(struct task_struct *p, int nice) ++{ ++ struct sched_attr attr = { ++ .sched_policy = SCHED_NORMAL, ++ .sched_nice = nice, ++ }; ++ WARN_ON_ONCE(sched_setattr_nocheck(p, &attr) != 0); ++} ++EXPORT_SYMBOL_GPL(sched_set_normal); ++ ++static int ++do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) ++{ ++ struct sched_param lparam; ++ ++ if (!param || pid < 0) ++ return -EINVAL; ++ if (copy_from_user(&lparam, param, sizeof(struct sched_param))) ++ return -EFAULT; ++ ++ CLASS(find_get_task, p)(pid); ++ if (!p) ++ return -ESRCH; ++ ++ return sched_setscheduler(p, policy, &lparam); ++} ++ ++/* ++ * Mimics kernel/events/core.c perf_copy_attr(). ++ */ ++static int sched_copy_attr(struct sched_attr __user *uattr, struct sched_attr *attr) ++{ ++ u32 size; ++ int ret; ++ ++ /* Zero the full structure, so that a short copy will be nice: */ ++ memset(attr, 0, sizeof(*attr)); ++ ++ ret = get_user(size, &uattr->size); ++ if (ret) ++ return ret; ++ ++ /* ABI compatibility quirk: */ ++ if (!size) ++ size = SCHED_ATTR_SIZE_VER0; ++ ++ if (size < SCHED_ATTR_SIZE_VER0 || size > PAGE_SIZE) ++ goto err_size; ++ ++ ret = copy_struct_from_user(attr, sizeof(*attr), uattr, size); ++ if (ret) { ++ if (ret == -E2BIG) ++ goto err_size; ++ return ret; ++ } ++ ++ /* ++ * XXX: Do we want to be lenient like existing syscalls; or do we want ++ * to be strict and return an error on out-of-bounds values? ++ */ ++ attr->sched_nice = clamp(attr->sched_nice, -20, 19); ++ ++ /* sched/core.c uses zero here but we already know ret is zero */ ++ return 0; ++ ++err_size: ++ put_user(sizeof(*attr), &uattr->size); ++ return -E2BIG; ++} ++ ++/** ++ * sys_sched_setscheduler - set/change the scheduler policy and RT priority ++ * @pid: the pid in question. ++ * @policy: new policy. ++ * ++ * Return: 0 on success. An error code otherwise. ++ * @param: structure containing the new RT priority. ++ */ ++SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, struct sched_param __user *, param) ++{ ++ if (policy < 0) ++ return -EINVAL; ++ ++ return do_sched_setscheduler(pid, policy, param); ++} ++ ++/** ++ * sys_sched_setparam - set/change the RT priority of a thread ++ * @pid: the pid in question. ++ * @param: structure containing the new RT priority. ++ * ++ * Return: 0 on success. An error code otherwise. ++ */ ++SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) ++{ ++ return do_sched_setscheduler(pid, SETPARAM_POLICY, param); ++} ++ ++static void get_params(struct task_struct *p, struct sched_attr *attr) ++{ ++ if (task_has_rt_policy(p)) ++ attr->sched_priority = p->rt_priority; ++ else ++ attr->sched_nice = task_nice(p); ++} ++ ++/** ++ * sys_sched_setattr - same as above, but with extended sched_attr ++ * @pid: the pid in question. ++ * @uattr: structure containing the extended parameters. ++ */ ++SYSCALL_DEFINE3(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr, ++ unsigned int, flags) ++{ ++ struct sched_attr attr; ++ int retval; ++ ++ if (!uattr || pid < 0 || flags) ++ return -EINVAL; ++ ++ retval = sched_copy_attr(uattr, &attr); ++ if (retval) ++ return retval; ++ ++ if ((int)attr.sched_policy < 0) ++ return -EINVAL; ++ ++ CLASS(find_get_task, p)(pid); ++ if (!p) ++ return -ESRCH; ++ ++ if (attr.sched_flags & SCHED_FLAG_KEEP_PARAMS) ++ get_params(p, &attr); ++ ++ return sched_setattr(p, &attr); ++} ++ ++/** ++ * sys_sched_getscheduler - get the policy (scheduling class) of a thread ++ * @pid: the pid in question. ++ * ++ * Return: On success, the policy of the thread. Otherwise, a negative error ++ * code. ++ */ ++SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) ++{ ++ struct task_struct *p; ++ int retval = -EINVAL; ++ ++ if (pid < 0) ++ return -ESRCH; ++ ++ guard(rcu)(); ++ p = find_process_by_pid(pid); ++ if (!p) ++ return -ESRCH; ++ ++ retval = security_task_getscheduler(p); ++ if (!retval) ++ retval = p->policy; ++ ++ return retval; ++} ++ ++/** ++ * sys_sched_getscheduler - get the RT priority of a thread ++ * @pid: the pid in question. ++ * @param: structure containing the RT priority. ++ * ++ * Return: On success, 0 and the RT priority is in @param. Otherwise, an error ++ * code. ++ */ ++SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) ++{ ++ struct sched_param lp = { .sched_priority = 0 }; ++ struct task_struct *p; ++ ++ if (!param || pid < 0) ++ return -EINVAL; ++ ++ scoped_guard (rcu) { ++ int retval; ++ ++ p = find_process_by_pid(pid); ++ if (!p) ++ return -EINVAL; ++ ++ retval = security_task_getscheduler(p); ++ if (retval) ++ return retval; ++ ++ if (task_has_rt_policy(p)) ++ lp.sched_priority = p->rt_priority; ++ } ++ ++ /* ++ * This one might sleep, we cannot do it with a spinlock held ... ++ */ ++ return copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; ++} ++ ++/* ++ * Copy the kernel size attribute structure (which might be larger ++ * than what user-space knows about) to user-space. ++ * ++ * Note that all cases are valid: user-space buffer can be larger or ++ * smaller than the kernel-space buffer. The usual case is that both ++ * have the same size. ++ */ ++static int ++sched_attr_copy_to_user(struct sched_attr __user *uattr, ++ struct sched_attr *kattr, ++ unsigned int usize) ++{ ++ unsigned int ksize = sizeof(*kattr); ++ ++ if (!access_ok(uattr, usize)) ++ return -EFAULT; ++ ++ /* ++ * sched_getattr() ABI forwards and backwards compatibility: ++ * ++ * If usize == ksize then we just copy everything to user-space and all is good. ++ * ++ * If usize < ksize then we only copy as much as user-space has space for, ++ * this keeps ABI compatibility as well. We skip the rest. ++ * ++ * If usize > ksize then user-space is using a newer version of the ABI, ++ * which part the kernel doesn't know about. Just ignore it - tooling can ++ * detect the kernel's knowledge of attributes from the attr->size value ++ * which is set to ksize in this case. ++ */ ++ kattr->size = min(usize, ksize); ++ ++ if (copy_to_user(uattr, kattr, kattr->size)) ++ return -EFAULT; ++ ++ return 0; ++} ++ ++/** ++ * sys_sched_getattr - similar to sched_getparam, but with sched_attr ++ * @pid: the pid in question. ++ * @uattr: structure containing the extended parameters. ++ * @usize: sizeof(attr) for fwd/bwd comp. ++ * @flags: for future extension. ++ */ ++SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr, ++ unsigned int, usize, unsigned int, flags) ++{ ++ struct sched_attr kattr = { }; ++ struct task_struct *p; ++ int retval; ++ ++ if (!uattr || pid < 0 || usize > PAGE_SIZE || ++ usize < SCHED_ATTR_SIZE_VER0 || flags) ++ return -EINVAL; ++ ++ scoped_guard (rcu) { ++ p = find_process_by_pid(pid); ++ if (!p) ++ return -ESRCH; ++ ++ retval = security_task_getscheduler(p); ++ if (retval) ++ return retval; ++ ++ kattr.sched_policy = p->policy; ++ if (p->sched_reset_on_fork) ++ kattr.sched_flags |= SCHED_FLAG_RESET_ON_FORK; ++ get_params(p, &kattr); ++ kattr.sched_flags &= SCHED_FLAG_ALL; ++ ++#ifdef CONFIG_UCLAMP_TASK ++ kattr.sched_util_min = p->uclamp_req[UCLAMP_MIN].value; ++ kattr.sched_util_max = p->uclamp_req[UCLAMP_MAX].value; ++#endif ++ } ++ ++ return sched_attr_copy_to_user(uattr, &kattr, usize); ++} ++ ++#ifdef CONFIG_SMP ++int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) ++{ ++ return 0; ++} ++#endif ++ ++static int ++__sched_setaffinity(struct task_struct *p, struct affinity_context *ctx) ++{ ++ int retval; ++ cpumask_var_t cpus_allowed, new_mask; ++ ++ if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) ++ return -ENOMEM; ++ ++ if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { ++ retval = -ENOMEM; ++ goto out_free_cpus_allowed; ++ } ++ ++ cpuset_cpus_allowed(p, cpus_allowed); ++ cpumask_and(new_mask, ctx->new_mask, cpus_allowed); ++ ++ ctx->new_mask = new_mask; ++ ctx->flags |= SCA_CHECK; ++ ++ retval = __set_cpus_allowed_ptr(p, ctx); ++ if (retval) ++ goto out_free_new_mask; ++ ++ cpuset_cpus_allowed(p, cpus_allowed); ++ if (!cpumask_subset(new_mask, cpus_allowed)) { ++ /* ++ * We must have raced with a concurrent cpuset ++ * update. Just reset the cpus_allowed to the ++ * cpuset's cpus_allowed ++ */ ++ cpumask_copy(new_mask, cpus_allowed); ++ ++ /* ++ * If SCA_USER is set, a 2nd call to __set_cpus_allowed_ptr() ++ * will restore the previous user_cpus_ptr value. ++ * ++ * In the unlikely event a previous user_cpus_ptr exists, ++ * we need to further restrict the mask to what is allowed ++ * by that old user_cpus_ptr. ++ */ ++ if (unlikely((ctx->flags & SCA_USER) && ctx->user_mask)) { ++ bool empty = !cpumask_and(new_mask, new_mask, ++ ctx->user_mask); ++ ++ if (WARN_ON_ONCE(empty)) ++ cpumask_copy(new_mask, cpus_allowed); ++ } ++ __set_cpus_allowed_ptr(p, ctx); ++ retval = -EINVAL; ++ } ++ ++out_free_new_mask: ++ free_cpumask_var(new_mask); ++out_free_cpus_allowed: ++ free_cpumask_var(cpus_allowed); ++ return retval; ++} ++ ++long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) ++{ ++ struct affinity_context ac; ++ struct cpumask *user_mask; ++ int retval; ++ ++ CLASS(find_get_task, p)(pid); ++ if (!p) ++ return -ESRCH; ++ ++ if (p->flags & PF_NO_SETAFFINITY) ++ return -EINVAL; ++ ++ if (!check_same_owner(p)) { ++ guard(rcu)(); ++ if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) ++ return -EPERM; ++ } ++ ++ retval = security_task_setscheduler(p); ++ if (retval) ++ return retval; ++ ++ /* ++ * With non-SMP configs, user_cpus_ptr/user_mask isn't used and ++ * alloc_user_cpus_ptr() returns NULL. ++ */ ++ user_mask = alloc_user_cpus_ptr(NUMA_NO_NODE); ++ if (user_mask) { ++ cpumask_copy(user_mask, in_mask); ++ } else if (IS_ENABLED(CONFIG_SMP)) { ++ return -ENOMEM; ++ } ++ ++ ac = (struct affinity_context){ ++ .new_mask = in_mask, ++ .user_mask = user_mask, ++ .flags = SCA_USER, ++ }; ++ ++ retval = __sched_setaffinity(p, &ac); ++ kfree(ac.user_mask); ++ ++ return retval; ++} ++ ++static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, ++ struct cpumask *new_mask) ++{ ++ if (len < cpumask_size()) ++ cpumask_clear(new_mask); ++ else if (len > cpumask_size()) ++ len = cpumask_size(); ++ ++ return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; ++} ++ ++/** ++ * sys_sched_setaffinity - set the CPU affinity of a process ++ * @pid: pid of the process ++ * @len: length in bytes of the bitmask pointed to by user_mask_ptr ++ * @user_mask_ptr: user-space pointer to the new CPU mask ++ * ++ * Return: 0 on success. An error code otherwise. ++ */ ++SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, ++ unsigned long __user *, user_mask_ptr) ++{ ++ cpumask_var_t new_mask; ++ int retval; ++ ++ if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) ++ return -ENOMEM; ++ ++ retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); ++ if (retval == 0) ++ retval = sched_setaffinity(pid, new_mask); ++ free_cpumask_var(new_mask); ++ return retval; ++} ++ ++long sched_getaffinity(pid_t pid, cpumask_t *mask) ++{ ++ struct task_struct *p; ++ int retval; ++ ++ guard(rcu)(); ++ p = find_process_by_pid(pid); ++ if (!p) ++ return -ESRCH; ++ ++ retval = security_task_getscheduler(p); ++ if (retval) ++ return retval; ++ ++ guard(raw_spinlock_irqsave)(&p->pi_lock); ++ cpumask_and(mask, &p->cpus_mask, cpu_active_mask); ++ ++ return retval; ++} ++ ++/** ++ * sys_sched_getaffinity - get the CPU affinity of a process ++ * @pid: pid of the process ++ * @len: length in bytes of the bitmask pointed to by user_mask_ptr ++ * @user_mask_ptr: user-space pointer to hold the current CPU mask ++ * ++ * Return: size of CPU mask copied to user_mask_ptr on success. An ++ * error code otherwise. ++ */ ++SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, ++ unsigned long __user *, user_mask_ptr) ++{ ++ int ret; ++ cpumask_var_t mask; ++ ++ if ((len * BITS_PER_BYTE) < nr_cpu_ids) ++ return -EINVAL; ++ if (len & (sizeof(unsigned long)-1)) ++ return -EINVAL; ++ ++ if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) ++ return -ENOMEM; ++ ++ ret = sched_getaffinity(pid, mask); ++ if (ret == 0) { ++ unsigned int retlen = min(len, cpumask_size()); ++ ++ if (copy_to_user(user_mask_ptr, cpumask_bits(mask), retlen)) ++ ret = -EFAULT; ++ else ++ ret = retlen; ++ } ++ free_cpumask_var(mask); ++ ++ return ret; ++} ++ ++static void do_sched_yield(void) ++{ ++ struct rq *rq; ++ struct rq_flags rf; ++ ++ if (!sched_yield_type) ++ return; ++ ++ rq = this_rq_lock_irq(&rf); ++ ++ schedstat_inc(rq->yld_count); ++ ++ if (1 == sched_yield_type) { ++ if (!rt_task(current)) ++ do_sched_yield_type_1(current, rq); ++ } else if (2 == sched_yield_type) { ++ if (rq->nr_running > 1) ++ rq->skip = current; ++ } ++ ++ preempt_disable(); ++ raw_spin_unlock_irq(&rq->lock); ++ sched_preempt_enable_no_resched(); ++ ++ schedule(); ++} ++ ++/** ++ * sys_sched_yield - yield the current processor to other threads. ++ * ++ * This function yields the current CPU to other tasks. If there are no ++ * other threads running on this CPU then this function will return. ++ * ++ * Return: 0. ++ */ ++SYSCALL_DEFINE0(sched_yield) ++{ ++ do_sched_yield(); ++ return 0; ++} ++ ++#if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) ++int __sched __cond_resched(void) ++{ ++ if (should_resched(0)) { ++ preempt_schedule_common(); ++ return 1; ++ } ++ /* ++ * In preemptible kernels, ->rcu_read_lock_nesting tells the tick ++ * whether the current CPU is in an RCU read-side critical section, ++ * so the tick can report quiescent states even for CPUs looping ++ * in kernel context. In contrast, in non-preemptible kernels, ++ * RCU readers leave no in-memory hints, which means that CPU-bound ++ * processes executing in kernel context might never report an ++ * RCU quiescent state. Therefore, the following code causes ++ * cond_resched() to report a quiescent state, but only when RCU ++ * is in urgent need of one. ++ */ ++#ifndef CONFIG_PREEMPT_RCU ++ rcu_all_qs(); ++#endif ++ return 0; ++} ++EXPORT_SYMBOL(__cond_resched); ++#endif ++ ++#ifdef CONFIG_PREEMPT_DYNAMIC ++#if defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) ++#define cond_resched_dynamic_enabled __cond_resched ++#define cond_resched_dynamic_disabled ((void *)&__static_call_return0) ++DEFINE_STATIC_CALL_RET0(cond_resched, __cond_resched); ++EXPORT_STATIC_CALL_TRAMP(cond_resched); ++ ++#define might_resched_dynamic_enabled __cond_resched ++#define might_resched_dynamic_disabled ((void *)&__static_call_return0) ++DEFINE_STATIC_CALL_RET0(might_resched, __cond_resched); ++EXPORT_STATIC_CALL_TRAMP(might_resched); ++#elif defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) ++static DEFINE_STATIC_KEY_FALSE(sk_dynamic_cond_resched); ++int __sched dynamic_cond_resched(void) ++{ ++ klp_sched_try_switch(); ++ if (!static_branch_unlikely(&sk_dynamic_cond_resched)) ++ return 0; ++ return __cond_resched(); ++} ++EXPORT_SYMBOL(dynamic_cond_resched); ++ ++static DEFINE_STATIC_KEY_FALSE(sk_dynamic_might_resched); ++int __sched dynamic_might_resched(void) ++{ ++ if (!static_branch_unlikely(&sk_dynamic_might_resched)) ++ return 0; ++ return __cond_resched(); ++} ++EXPORT_SYMBOL(dynamic_might_resched); ++#endif ++#endif ++ ++/* ++ * __cond_resched_lock() - if a reschedule is pending, drop the given lock, ++ * call schedule, and on return reacquire the lock. ++ * ++ * This works OK both with and without CONFIG_PREEMPTION. We do strange low-level ++ * operations here to prevent schedule() from being called twice (once via ++ * spin_unlock(), once by hand). ++ */ ++int __cond_resched_lock(spinlock_t *lock) ++{ ++ int resched = should_resched(PREEMPT_LOCK_OFFSET); ++ int ret = 0; ++ ++ lockdep_assert_held(lock); ++ ++ if (spin_needbreak(lock) || resched) { ++ spin_unlock(lock); ++ if (!_cond_resched()) ++ cpu_relax(); ++ ret = 1; ++ spin_lock(lock); ++ } ++ return ret; ++} ++EXPORT_SYMBOL(__cond_resched_lock); ++ ++int __cond_resched_rwlock_read(rwlock_t *lock) ++{ ++ int resched = should_resched(PREEMPT_LOCK_OFFSET); ++ int ret = 0; ++ ++ lockdep_assert_held_read(lock); ++ ++ if (rwlock_needbreak(lock) || resched) { ++ read_unlock(lock); ++ if (!_cond_resched()) ++ cpu_relax(); ++ ret = 1; ++ read_lock(lock); ++ } ++ return ret; ++} ++EXPORT_SYMBOL(__cond_resched_rwlock_read); ++ ++int __cond_resched_rwlock_write(rwlock_t *lock) ++{ ++ int resched = should_resched(PREEMPT_LOCK_OFFSET); ++ int ret = 0; ++ ++ lockdep_assert_held_write(lock); ++ ++ if (rwlock_needbreak(lock) || resched) { ++ write_unlock(lock); ++ if (!_cond_resched()) ++ cpu_relax(); ++ ret = 1; ++ write_lock(lock); ++ } ++ return ret; ++} ++EXPORT_SYMBOL(__cond_resched_rwlock_write); ++ ++#ifdef CONFIG_PREEMPT_DYNAMIC ++ ++#ifdef CONFIG_GENERIC_ENTRY ++#include <linux/entry-common.h> ++#endif ++ ++/* ++ * SC:cond_resched ++ * SC:might_resched ++ * SC:preempt_schedule ++ * SC:preempt_schedule_notrace ++ * SC:irqentry_exit_cond_resched ++ * ++ * ++ * NONE: ++ * cond_resched <- __cond_resched ++ * might_resched <- RET0 ++ * preempt_schedule <- NOP ++ * preempt_schedule_notrace <- NOP ++ * irqentry_exit_cond_resched <- NOP ++ * ++ * VOLUNTARY: ++ * cond_resched <- __cond_resched ++ * might_resched <- __cond_resched ++ * preempt_schedule <- NOP ++ * preempt_schedule_notrace <- NOP ++ * irqentry_exit_cond_resched <- NOP ++ * ++ * FULL: ++ * cond_resched <- RET0 ++ * might_resched <- RET0 ++ * preempt_schedule <- preempt_schedule ++ * preempt_schedule_notrace <- preempt_schedule_notrace ++ * irqentry_exit_cond_resched <- irqentry_exit_cond_resched ++ */ ++ ++enum { ++ preempt_dynamic_undefined = -1, ++ preempt_dynamic_none, ++ preempt_dynamic_voluntary, ++ preempt_dynamic_full, ++}; ++ ++int preempt_dynamic_mode = preempt_dynamic_undefined; ++ ++int sched_dynamic_mode(const char *str) ++{ ++ if (!strcmp(str, "none")) ++ return preempt_dynamic_none; ++ ++ if (!strcmp(str, "voluntary")) ++ return preempt_dynamic_voluntary; ++ ++ if (!strcmp(str, "full")) ++ return preempt_dynamic_full; ++ ++ return -EINVAL; ++} ++ ++#if defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) ++#define preempt_dynamic_enable(f) static_call_update(f, f##_dynamic_enabled) ++#define preempt_dynamic_disable(f) static_call_update(f, f##_dynamic_disabled) ++#elif defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) ++#define preempt_dynamic_enable(f) static_key_enable(&sk_dynamic_##f.key) ++#define preempt_dynamic_disable(f) static_key_disable(&sk_dynamic_##f.key) ++#else ++#error "Unsupported PREEMPT_DYNAMIC mechanism" ++#endif ++ ++static DEFINE_MUTEX(sched_dynamic_mutex); ++static bool klp_override; ++ ++static void __sched_dynamic_update(int mode) ++{ ++ /* ++ * Avoid {NONE,VOLUNTARY} -> FULL transitions from ever ending up in ++ * the ZERO state, which is invalid. ++ */ ++ if (!klp_override) ++ preempt_dynamic_enable(cond_resched); ++ preempt_dynamic_enable(cond_resched); ++ preempt_dynamic_enable(might_resched); ++ preempt_dynamic_enable(preempt_schedule); ++ preempt_dynamic_enable(preempt_schedule_notrace); ++ preempt_dynamic_enable(irqentry_exit_cond_resched); ++ ++ switch (mode) { ++ case preempt_dynamic_none: ++ if (!klp_override) ++ preempt_dynamic_enable(cond_resched); ++ preempt_dynamic_disable(might_resched); ++ preempt_dynamic_disable(preempt_schedule); ++ preempt_dynamic_disable(preempt_schedule_notrace); ++ preempt_dynamic_disable(irqentry_exit_cond_resched); ++ if (mode != preempt_dynamic_mode) ++ pr_info("Dynamic Preempt: none\n"); ++ break; ++ ++ case preempt_dynamic_voluntary: ++ if (!klp_override) ++ preempt_dynamic_enable(cond_resched); ++ preempt_dynamic_enable(might_resched); ++ preempt_dynamic_disable(preempt_schedule); ++ preempt_dynamic_disable(preempt_schedule_notrace); ++ preempt_dynamic_disable(irqentry_exit_cond_resched); ++ if (mode != preempt_dynamic_mode) ++ pr_info("Dynamic Preempt: voluntary\n"); ++ break; ++ ++ case preempt_dynamic_full: ++ if (!klp_override) ++ preempt_dynamic_enable(cond_resched); ++ preempt_dynamic_disable(might_resched); ++ preempt_dynamic_enable(preempt_schedule); ++ preempt_dynamic_enable(preempt_schedule_notrace); ++ preempt_dynamic_enable(irqentry_exit_cond_resched); ++ if (mode != preempt_dynamic_mode) ++ pr_info("Dynamic Preempt: full\n"); ++ break; ++ } ++ ++ preempt_dynamic_mode = mode; ++} ++ ++void sched_dynamic_update(int mode) ++{ ++ mutex_lock(&sched_dynamic_mutex); ++ __sched_dynamic_update(mode); ++ mutex_unlock(&sched_dynamic_mutex); ++} ++ ++#ifdef CONFIG_HAVE_PREEMPT_DYNAMIC_CALL ++ ++static int klp_cond_resched(void) ++{ ++ __klp_sched_try_switch(); ++ return __cond_resched(); ++} ++ ++void sched_dynamic_klp_enable(void) ++{ ++ mutex_lock(&sched_dynamic_mutex); ++ ++ klp_override = true; ++ static_call_update(cond_resched, klp_cond_resched); ++ ++ mutex_unlock(&sched_dynamic_mutex); ++} ++ ++void sched_dynamic_klp_disable(void) ++{ ++ mutex_lock(&sched_dynamic_mutex); ++ ++ klp_override = false; ++ __sched_dynamic_update(preempt_dynamic_mode); ++ ++ mutex_unlock(&sched_dynamic_mutex); ++} ++ ++#endif /* CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */ ++ ++ ++static int __init setup_preempt_mode(char *str) ++{ ++ int mode = sched_dynamic_mode(str); ++ if (mode < 0) { ++ pr_warn("Dynamic Preempt: unsupported mode: %s\n", str); ++ return 0; ++ } ++ ++ sched_dynamic_update(mode); ++ return 1; ++} ++__setup("preempt=", setup_preempt_mode); ++ ++static void __init preempt_dynamic_init(void) ++{ ++ if (preempt_dynamic_mode == preempt_dynamic_undefined) { ++ if (IS_ENABLED(CONFIG_PREEMPT_NONE)) { ++ sched_dynamic_update(preempt_dynamic_none); ++ } else if (IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY)) { ++ sched_dynamic_update(preempt_dynamic_voluntary); ++ } else { ++ /* Default static call setting, nothing to do */ ++ WARN_ON_ONCE(!IS_ENABLED(CONFIG_PREEMPT)); ++ preempt_dynamic_mode = preempt_dynamic_full; ++ pr_info("Dynamic Preempt: full\n"); ++ } ++ } ++} ++ ++#define PREEMPT_MODEL_ACCESSOR(mode) \ ++ bool preempt_model_##mode(void) \ ++ { \ ++ WARN_ON_ONCE(preempt_dynamic_mode == preempt_dynamic_undefined); \ ++ return preempt_dynamic_mode == preempt_dynamic_##mode; \ ++ } \ ++ EXPORT_SYMBOL_GPL(preempt_model_##mode) ++ ++PREEMPT_MODEL_ACCESSOR(none); ++PREEMPT_MODEL_ACCESSOR(voluntary); ++PREEMPT_MODEL_ACCESSOR(full); ++ ++#else /* !CONFIG_PREEMPT_DYNAMIC */ ++ ++static inline void preempt_dynamic_init(void) { } ++ ++#endif /* #ifdef CONFIG_PREEMPT_DYNAMIC */ ++ ++/** ++ * yield - yield the current processor to other threads. ++ * ++ * Do not ever use this function, there's a 99% chance you're doing it wrong. ++ * ++ * The scheduler is at all times free to pick the calling task as the most ++ * eligible task to run, if removing the yield() call from your code breaks ++ * it, it's already broken. ++ * ++ * Typical broken usage is: ++ * ++ * while (!event) ++ * yield(); ++ * ++ * where one assumes that yield() will let 'the other' process run that will ++ * make event true. If the current task is a SCHED_FIFO task that will never ++ * happen. Never use yield() as a progress guarantee!! ++ * ++ * If you want to use yield() to wait for something, use wait_event(). ++ * If you want to use yield() to be 'nice' for others, use cond_resched(). ++ * If you still want to use yield(), do not! ++ */ ++void __sched yield(void) ++{ ++ set_current_state(TASK_RUNNING); ++ do_sched_yield(); ++} ++EXPORT_SYMBOL(yield); ++ ++/** ++ * yield_to - yield the current processor to another thread in ++ * your thread group, or accelerate that thread toward the ++ * processor it's on. ++ * @p: target task ++ * @preempt: whether task preemption is allowed or not ++ * ++ * It's the caller's job to ensure that the target task struct ++ * can't go away on us before we can do any checks. ++ * ++ * In Alt schedule FW, yield_to is not supported. ++ * ++ * Return: ++ * true (>0) if we indeed boosted the target task. ++ * false (0) if we failed to boost the target. ++ * -ESRCH if there's no task to yield to. ++ */ ++int __sched yield_to(struct task_struct *p, bool preempt) ++{ ++ return 0; ++} ++EXPORT_SYMBOL_GPL(yield_to); ++ ++int io_schedule_prepare(void) ++{ ++ int old_iowait = current->in_iowait; ++ ++ current->in_iowait = 1; ++ blk_flush_plug(current->plug, true); ++ return old_iowait; ++} ++ ++void io_schedule_finish(int token) ++{ ++ current->in_iowait = token; ++} ++ ++/* ++ * This task is about to go to sleep on IO. Increment rq->nr_iowait so ++ * that process accounting knows that this is a task in IO wait state. ++ * ++ * But don't do that if it is a deliberate, throttling IO wait (this task ++ * has set its backing_dev_info: the queue against which it should throttle) ++ */ ++ ++long __sched io_schedule_timeout(long timeout) ++{ ++ int token; ++ long ret; ++ ++ token = io_schedule_prepare(); ++ ret = schedule_timeout(timeout); ++ io_schedule_finish(token); ++ ++ return ret; ++} ++EXPORT_SYMBOL(io_schedule_timeout); ++ ++void __sched io_schedule(void) ++{ ++ int token; ++ ++ token = io_schedule_prepare(); ++ schedule(); ++ io_schedule_finish(token); ++} ++EXPORT_SYMBOL(io_schedule); ++ ++/** ++ * sys_sched_get_priority_max - return maximum RT priority. ++ * @policy: scheduling class. ++ * ++ * Return: On success, this syscall returns the maximum ++ * rt_priority that can be used by a given scheduling class. ++ * On failure, a negative error code is returned. ++ */ ++SYSCALL_DEFINE1(sched_get_priority_max, int, policy) ++{ ++ int ret = -EINVAL; ++ ++ switch (policy) { ++ case SCHED_FIFO: ++ case SCHED_RR: ++ ret = MAX_RT_PRIO - 1; ++ break; ++ case SCHED_NORMAL: ++ case SCHED_BATCH: ++ case SCHED_IDLE: ++ ret = 0; ++ break; ++ } ++ return ret; ++} ++ ++/** ++ * sys_sched_get_priority_min - return minimum RT priority. ++ * @policy: scheduling class. ++ * ++ * Return: On success, this syscall returns the minimum ++ * rt_priority that can be used by a given scheduling class. ++ * On failure, a negative error code is returned. ++ */ ++SYSCALL_DEFINE1(sched_get_priority_min, int, policy) ++{ ++ int ret = -EINVAL; ++ ++ switch (policy) { ++ case SCHED_FIFO: ++ case SCHED_RR: ++ ret = 1; ++ break; ++ case SCHED_NORMAL: ++ case SCHED_BATCH: ++ case SCHED_IDLE: ++ ret = 0; ++ break; ++ } ++ return ret; ++} ++ ++static int sched_rr_get_interval(pid_t pid, struct timespec64 *t) ++{ ++ struct task_struct *p; ++ int retval; ++ ++ alt_sched_debug(); ++ ++ if (pid < 0) ++ return -EINVAL; ++ ++ guard(rcu)(); ++ p = find_process_by_pid(pid); ++ if (!p) ++ return -EINVAL; ++ ++ retval = security_task_getscheduler(p); ++ if (retval) ++ return retval; ++ ++ *t = ns_to_timespec64(sched_timeslice_ns); ++ return 0; ++} ++ ++/** ++ * sys_sched_rr_get_interval - return the default timeslice of a process. ++ * @pid: pid of the process. ++ * @interval: userspace pointer to the timeslice value. ++ * ++ * ++ * Return: On success, 0 and the timeslice is in @interval. Otherwise, ++ * an error code. ++ */ ++SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, ++ struct __kernel_timespec __user *, interval) ++{ ++ struct timespec64 t; ++ int retval = sched_rr_get_interval(pid, &t); ++ ++ if (retval == 0) ++ retval = put_timespec64(&t, interval); ++ ++ return retval; ++} ++ ++#ifdef CONFIG_COMPAT_32BIT_TIME ++SYSCALL_DEFINE2(sched_rr_get_interval_time32, pid_t, pid, ++ struct old_timespec32 __user *, interval) ++{ ++ struct timespec64 t; ++ int retval = sched_rr_get_interval(pid, &t); ++ ++ if (retval == 0) ++ retval = put_old_timespec32(&t, interval); ++ return retval; ++} ++#endif ++ ++void sched_show_task(struct task_struct *p) ++{ ++ unsigned long free = 0; ++ int ppid; ++ ++ if (!try_get_task_stack(p)) ++ return; ++ ++ pr_info("task:%-15.15s state:%c", p->comm, task_state_to_char(p)); ++ ++ if (task_is_running(p)) ++ pr_cont(" running task "); ++#ifdef CONFIG_DEBUG_STACK_USAGE ++ free = stack_not_used(p); ++#endif ++ ppid = 0; ++ rcu_read_lock(); ++ if (pid_alive(p)) ++ ppid = task_pid_nr(rcu_dereference(p->real_parent)); ++ rcu_read_unlock(); ++ pr_cont(" stack:%-5lu pid:%-5d tgid:%-5d ppid:%-6d flags:0x%08lx\n", ++ free, task_pid_nr(p), task_tgid_nr(p), ++ ppid, read_task_thread_flags(p)); ++ ++ print_worker_info(KERN_INFO, p); ++ print_stop_info(KERN_INFO, p); ++ show_stack(p, NULL, KERN_INFO); ++ put_task_stack(p); ++} ++EXPORT_SYMBOL_GPL(sched_show_task); ++ ++static inline bool ++state_filter_match(unsigned long state_filter, struct task_struct *p) ++{ ++ unsigned int state = READ_ONCE(p->__state); ++ ++ /* no filter, everything matches */ ++ if (!state_filter) ++ return true; ++ ++ /* filter, but doesn't match */ ++ if (!(state & state_filter)) ++ return false; ++ ++ /* ++ * When looking for TASK_UNINTERRUPTIBLE skip TASK_IDLE (allows ++ * TASK_KILLABLE). ++ */ ++ if (state_filter == TASK_UNINTERRUPTIBLE && (state & TASK_NOLOAD)) ++ return false; ++ ++ return true; ++} ++ ++ ++void show_state_filter(unsigned int state_filter) ++{ ++ struct task_struct *g, *p; ++ ++ rcu_read_lock(); ++ for_each_process_thread(g, p) { ++ /* ++ * reset the NMI-timeout, listing all files on a slow ++ * console might take a lot of time: ++ * Also, reset softlockup watchdogs on all CPUs, because ++ * another CPU might be blocked waiting for us to process ++ * an IPI. ++ */ ++ touch_nmi_watchdog(); ++ touch_all_softlockup_watchdogs(); ++ if (state_filter_match(state_filter, p)) ++ sched_show_task(p); ++ } ++ ++#ifdef CONFIG_SCHED_DEBUG ++ /* TODO: Alt schedule FW should support this ++ if (!state_filter) ++ sysrq_sched_debug_show(); ++ */ ++#endif ++ rcu_read_unlock(); ++ /* ++ * Only show locks if all tasks are dumped: ++ */ ++ if (!state_filter) ++ debug_show_all_locks(); ++} ++ ++void dump_cpu_task(int cpu) ++{ ++ if (cpu == smp_processor_id() && in_hardirq()) { ++ struct pt_regs *regs; ++ ++ regs = get_irq_regs(); ++ if (regs) { ++ show_regs(regs); ++ return; ++ } ++ } ++ ++ if (trigger_single_cpu_backtrace(cpu)) ++ return; ++ ++ pr_info("Task dump for CPU %d:\n", cpu); ++ sched_show_task(cpu_curr(cpu)); ++} ++ ++/** ++ * init_idle - set up an idle thread for a given CPU ++ * @idle: task in question ++ * @cpu: CPU the idle task belongs to ++ * ++ * NOTE: this function does not set the idle thread's NEED_RESCHED ++ * flag, to make booting more robust. ++ */ ++void __init init_idle(struct task_struct *idle, int cpu) ++{ ++#ifdef CONFIG_SMP ++ struct affinity_context ac = (struct affinity_context) { ++ .new_mask = cpumask_of(cpu), ++ .flags = 0, ++ }; ++#endif ++ struct rq *rq = cpu_rq(cpu); ++ unsigned long flags; ++ ++ __sched_fork(0, idle); ++ ++ raw_spin_lock_irqsave(&idle->pi_lock, flags); ++ raw_spin_lock(&rq->lock); ++ ++ idle->last_ran = rq->clock_task; ++ idle->__state = TASK_RUNNING; ++ /* ++ * PF_KTHREAD should already be set at this point; regardless, make it ++ * look like a proper per-CPU kthread. ++ */ ++ idle->flags |= PF_KTHREAD | PF_NO_SETAFFINITY; ++ kthread_set_per_cpu(idle, cpu); ++ ++ sched_queue_init_idle(&rq->queue, idle); ++ ++#ifdef CONFIG_SMP ++ /* ++ * It's possible that init_idle() gets called multiple times on a task, ++ * in that case do_set_cpus_allowed() will not do the right thing. ++ * ++ * And since this is boot we can forgo the serialisation. ++ */ ++ set_cpus_allowed_common(idle, &ac); ++#endif ++ ++ /* Silence PROVE_RCU */ ++ rcu_read_lock(); ++ __set_task_cpu(idle, cpu); ++ rcu_read_unlock(); ++ ++ rq->idle = idle; ++ rcu_assign_pointer(rq->curr, idle); ++ idle->on_cpu = 1; ++ ++ raw_spin_unlock(&rq->lock); ++ raw_spin_unlock_irqrestore(&idle->pi_lock, flags); ++ ++ /* Set the preempt count _outside_ the spinlocks! */ ++ init_idle_preempt_count(idle, cpu); ++ ++ ftrace_graph_init_idle_task(idle, cpu); ++ vtime_init_idle(idle, cpu); ++#ifdef CONFIG_SMP ++ sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu); ++#endif ++} ++ ++#ifdef CONFIG_SMP ++ ++int cpuset_cpumask_can_shrink(const struct cpumask __maybe_unused *cur, ++ const struct cpumask __maybe_unused *trial) ++{ ++ return 1; ++} ++ ++int task_can_attach(struct task_struct *p) ++{ ++ int ret = 0; ++ ++ /* ++ * Kthreads which disallow setaffinity shouldn't be moved ++ * to a new cpuset; we don't want to change their CPU ++ * affinity and isolating such threads by their set of ++ * allowed nodes is unnecessary. Thus, cpusets are not ++ * applicable for such threads. This prevents checking for ++ * success of set_cpus_allowed_ptr() on all attached tasks ++ * before cpus_mask may be changed. ++ */ ++ if (p->flags & PF_NO_SETAFFINITY) ++ ret = -EINVAL; ++ ++ return ret; ++} ++ ++bool sched_smp_initialized __read_mostly; ++ ++#ifdef CONFIG_HOTPLUG_CPU ++/* ++ * Ensures that the idle task is using init_mm right before its CPU goes ++ * offline. ++ */ ++void idle_task_exit(void) ++{ ++ struct mm_struct *mm = current->active_mm; ++ ++ BUG_ON(current != this_rq()->idle); ++ ++ if (mm != &init_mm) { ++ switch_mm(mm, &init_mm, current); ++ finish_arch_post_lock_switch(); ++ } ++ ++ /* finish_cpu(), as ran on the BP, will clean up the active_mm state */ ++} ++ ++static int __balance_push_cpu_stop(void *arg) ++{ ++ struct task_struct *p = arg; ++ struct rq *rq = this_rq(); ++ struct rq_flags rf; ++ int cpu; ++ ++ raw_spin_lock_irq(&p->pi_lock); ++ rq_lock(rq, &rf); ++ ++ update_rq_clock(rq); ++ ++ if (task_rq(p) == rq && task_on_rq_queued(p)) { ++ cpu = select_fallback_rq(rq->cpu, p); ++ rq = __migrate_task(rq, p, cpu); ++ } ++ ++ rq_unlock(rq, &rf); ++ raw_spin_unlock_irq(&p->pi_lock); ++ ++ put_task_struct(p); ++ ++ return 0; ++} ++ ++static DEFINE_PER_CPU(struct cpu_stop_work, push_work); ++ ++/* ++ * This is enabled below SCHED_AP_ACTIVE; when !cpu_active(), but only ++ * effective when the hotplug motion is down. ++ */ ++static void balance_push(struct rq *rq) ++{ ++ struct task_struct *push_task = rq->curr; ++ ++ lockdep_assert_held(&rq->lock); ++ ++ /* ++ * Ensure the thing is persistent until balance_push_set(.on = false); ++ */ ++ rq->balance_callback = &balance_push_callback; ++ ++ /* ++ * Only active while going offline and when invoked on the outgoing ++ * CPU. ++ */ ++ if (!cpu_dying(rq->cpu) || rq != this_rq()) ++ return; ++ ++ /* ++ * Both the cpu-hotplug and stop task are in this case and are ++ * required to complete the hotplug process. ++ */ ++ if (kthread_is_per_cpu(push_task) || ++ is_migration_disabled(push_task)) { ++ ++ /* ++ * If this is the idle task on the outgoing CPU try to wake ++ * up the hotplug control thread which might wait for the ++ * last task to vanish. The rcuwait_active() check is ++ * accurate here because the waiter is pinned on this CPU ++ * and can't obviously be running in parallel. ++ * ++ * On RT kernels this also has to check whether there are ++ * pinned and scheduled out tasks on the runqueue. They ++ * need to leave the migrate disabled section first. ++ */ ++ if (!rq->nr_running && !rq_has_pinned_tasks(rq) && ++ rcuwait_active(&rq->hotplug_wait)) { ++ raw_spin_unlock(&rq->lock); ++ rcuwait_wake_up(&rq->hotplug_wait); ++ raw_spin_lock(&rq->lock); ++ } ++ return; ++ } ++ ++ get_task_struct(push_task); ++ /* ++ * Temporarily drop rq->lock such that we can wake-up the stop task. ++ * Both preemption and IRQs are still disabled. ++ */ ++ preempt_disable(); ++ raw_spin_unlock(&rq->lock); ++ stop_one_cpu_nowait(rq->cpu, __balance_push_cpu_stop, push_task, ++ this_cpu_ptr(&push_work)); ++ preempt_enable(); ++ /* ++ * At this point need_resched() is true and we'll take the loop in ++ * schedule(). The next pick is obviously going to be the stop task ++ * which kthread_is_per_cpu() and will push this task away. ++ */ ++ raw_spin_lock(&rq->lock); ++} ++ ++static void balance_push_set(int cpu, bool on) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ struct rq_flags rf; ++ ++ rq_lock_irqsave(rq, &rf); ++ if (on) { ++ WARN_ON_ONCE(rq->balance_callback); ++ rq->balance_callback = &balance_push_callback; ++ } else if (rq->balance_callback == &balance_push_callback) { ++ rq->balance_callback = NULL; ++ } ++ rq_unlock_irqrestore(rq, &rf); ++} ++ ++/* ++ * Invoked from a CPUs hotplug control thread after the CPU has been marked ++ * inactive. All tasks which are not per CPU kernel threads are either ++ * pushed off this CPU now via balance_push() or placed on a different CPU ++ * during wakeup. Wait until the CPU is quiescent. ++ */ ++static void balance_hotplug_wait(void) ++{ ++ struct rq *rq = this_rq(); ++ ++ rcuwait_wait_event(&rq->hotplug_wait, ++ rq->nr_running == 1 && !rq_has_pinned_tasks(rq), ++ TASK_UNINTERRUPTIBLE); ++} ++ ++#else ++ ++static void balance_push(struct rq *rq) ++{ ++} ++ ++static void balance_push_set(int cpu, bool on) ++{ ++} ++ ++static inline void balance_hotplug_wait(void) ++{ ++} ++#endif /* CONFIG_HOTPLUG_CPU */ ++ ++static void set_rq_offline(struct rq *rq) ++{ ++ if (rq->online) { ++ update_rq_clock(rq); ++ rq->online = false; ++ } ++} ++ ++static void set_rq_online(struct rq *rq) ++{ ++ if (!rq->online) ++ rq->online = true; ++} ++ ++/* ++ * used to mark begin/end of suspend/resume: ++ */ ++static int num_cpus_frozen; ++ ++/* ++ * Update cpusets according to cpu_active mask. If cpusets are ++ * disabled, cpuset_update_active_cpus() becomes a simple wrapper ++ * around partition_sched_domains(). ++ * ++ * If we come here as part of a suspend/resume, don't touch cpusets because we ++ * want to restore it back to its original state upon resume anyway. ++ */ ++static void cpuset_cpu_active(void) ++{ ++ if (cpuhp_tasks_frozen) { ++ /* ++ * num_cpus_frozen tracks how many CPUs are involved in suspend ++ * resume sequence. As long as this is not the last online ++ * operation in the resume sequence, just build a single sched ++ * domain, ignoring cpusets. ++ */ ++ partition_sched_domains(1, NULL, NULL); ++ if (--num_cpus_frozen) ++ return; ++ /* ++ * This is the last CPU online operation. So fall through and ++ * restore the original sched domains by considering the ++ * cpuset configurations. ++ */ ++ cpuset_force_rebuild(); ++ } ++ ++ cpuset_update_active_cpus(); ++} ++ ++static int cpuset_cpu_inactive(unsigned int cpu) ++{ ++ if (!cpuhp_tasks_frozen) { ++ cpuset_update_active_cpus(); ++ } else { ++ num_cpus_frozen++; ++ partition_sched_domains(1, NULL, NULL); ++ } ++ return 0; ++} ++ ++int sched_cpu_activate(unsigned int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ unsigned long flags; ++ ++ /* ++ * Clear the balance_push callback and prepare to schedule ++ * regular tasks. ++ */ ++ balance_push_set(cpu, false); ++ ++#ifdef CONFIG_SCHED_SMT ++ /* ++ * When going up, increment the number of cores with SMT present. ++ */ ++ if (cpumask_weight(cpu_smt_mask(cpu)) == 2) ++ static_branch_inc_cpuslocked(&sched_smt_present); ++#endif ++ set_cpu_active(cpu, true); ++ ++ if (sched_smp_initialized) ++ cpuset_cpu_active(); ++ ++ /* ++ * Put the rq online, if not already. This happens: ++ * ++ * 1) In the early boot process, because we build the real domains ++ * after all cpus have been brought up. ++ * ++ * 2) At runtime, if cpuset_cpu_active() fails to rebuild the ++ * domains. ++ */ ++ raw_spin_lock_irqsave(&rq->lock, flags); ++ set_rq_online(rq); ++ raw_spin_unlock_irqrestore(&rq->lock, flags); ++ ++ return 0; ++} ++ ++int sched_cpu_deactivate(unsigned int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ unsigned long flags; ++ int ret; ++ ++ set_cpu_active(cpu, false); ++ ++ /* ++ * From this point forward, this CPU will refuse to run any task that ++ * is not: migrate_disable() or KTHREAD_IS_PER_CPU, and will actively ++ * push those tasks away until this gets cleared, see ++ * sched_cpu_dying(). ++ */ ++ balance_push_set(cpu, true); ++ ++ /* ++ * We've cleared cpu_active_mask, wait for all preempt-disabled and RCU ++ * users of this state to go away such that all new such users will ++ * observe it. ++ * ++ * Specifically, we rely on ttwu to no longer target this CPU, see ++ * ttwu_queue_cond() and is_cpu_allowed(). ++ * ++ * Do sync before park smpboot threads to take care the rcu boost case. ++ */ ++ synchronize_rcu(); ++ ++ raw_spin_lock_irqsave(&rq->lock, flags); ++ set_rq_offline(rq); ++ raw_spin_unlock_irqrestore(&rq->lock, flags); ++ ++#ifdef CONFIG_SCHED_SMT ++ /* ++ * When going down, decrement the number of cores with SMT present. ++ */ ++ if (cpumask_weight(cpu_smt_mask(cpu)) == 2) { ++ static_branch_dec_cpuslocked(&sched_smt_present); ++ if (!static_branch_likely(&sched_smt_present)) ++ cpumask_clear(&sched_sg_idle_mask); ++ } ++#endif ++ ++ if (!sched_smp_initialized) ++ return 0; ++ ++ ret = cpuset_cpu_inactive(cpu); ++ if (ret) { ++ balance_push_set(cpu, false); ++ set_cpu_active(cpu, true); ++ return ret; ++ } ++ ++ return 0; ++} ++ ++static void sched_rq_cpu_starting(unsigned int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ ++ rq->calc_load_update = calc_load_update; ++} ++ ++int sched_cpu_starting(unsigned int cpu) ++{ ++ sched_rq_cpu_starting(cpu); ++ sched_tick_start(cpu); ++ return 0; ++} ++ ++#ifdef CONFIG_HOTPLUG_CPU ++ ++/* ++ * Invoked immediately before the stopper thread is invoked to bring the ++ * CPU down completely. At this point all per CPU kthreads except the ++ * hotplug thread (current) and the stopper thread (inactive) have been ++ * either parked or have been unbound from the outgoing CPU. Ensure that ++ * any of those which might be on the way out are gone. ++ * ++ * If after this point a bound task is being woken on this CPU then the ++ * responsible hotplug callback has failed to do it's job. ++ * sched_cpu_dying() will catch it with the appropriate fireworks. ++ */ ++int sched_cpu_wait_empty(unsigned int cpu) ++{ ++ balance_hotplug_wait(); ++ return 0; ++} ++ ++/* ++ * Since this CPU is going 'away' for a while, fold any nr_active delta we ++ * might have. Called from the CPU stopper task after ensuring that the ++ * stopper is the last running task on the CPU, so nr_active count is ++ * stable. We need to take the teardown thread which is calling this into ++ * account, so we hand in adjust = 1 to the load calculation. ++ * ++ * Also see the comment "Global load-average calculations". ++ */ ++static void calc_load_migrate(struct rq *rq) ++{ ++ long delta = calc_load_fold_active(rq, 1); ++ ++ if (delta) ++ atomic_long_add(delta, &calc_load_tasks); ++} ++ ++static void dump_rq_tasks(struct rq *rq, const char *loglvl) ++{ ++ struct task_struct *g, *p; ++ int cpu = cpu_of(rq); ++ ++ lockdep_assert_held(&rq->lock); ++ ++ printk("%sCPU%d enqueued tasks (%u total):\n", loglvl, cpu, rq->nr_running); ++ for_each_process_thread(g, p) { ++ if (task_cpu(p) != cpu) ++ continue; ++ ++ if (!task_on_rq_queued(p)) ++ continue; ++ ++ printk("%s\tpid: %d, name: %s\n", loglvl, p->pid, p->comm); ++ } ++} ++ ++int sched_cpu_dying(unsigned int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ unsigned long flags; ++ ++ /* Handle pending wakeups and then migrate everything off */ ++ sched_tick_stop(cpu); ++ ++ raw_spin_lock_irqsave(&rq->lock, flags); ++ if (rq->nr_running != 1 || rq_has_pinned_tasks(rq)) { ++ WARN(true, "Dying CPU not properly vacated!"); ++ dump_rq_tasks(rq, KERN_WARNING); ++ } ++ raw_spin_unlock_irqrestore(&rq->lock, flags); ++ ++ calc_load_migrate(rq); ++ hrtick_clear(rq); ++ return 0; ++} ++#endif ++ ++#ifdef CONFIG_SMP ++static void sched_init_topology_cpumask_early(void) ++{ ++ int cpu; ++ cpumask_t *tmp; ++ ++ for_each_possible_cpu(cpu) { ++ /* init topo masks */ ++ tmp = per_cpu(sched_cpu_topo_masks, cpu); ++ ++ cpumask_copy(tmp, cpumask_of(cpu)); ++ tmp++; ++ cpumask_copy(tmp, cpu_possible_mask); ++ per_cpu(sched_cpu_llc_mask, cpu) = tmp; ++ per_cpu(sched_cpu_topo_end_mask, cpu) = ++tmp; ++ /*per_cpu(sd_llc_id, cpu) = cpu;*/ ++ } ++} ++ ++#define TOPOLOGY_CPUMASK(name, mask, last)\ ++ if (cpumask_and(topo, topo, mask)) { \ ++ cpumask_copy(topo, mask); \ ++ printk(KERN_INFO "sched: cpu#%02d topo: 0x%08lx - "#name, \ ++ cpu, (topo++)->bits[0]); \ ++ } \ ++ if (!last) \ ++ bitmap_complement(cpumask_bits(topo), cpumask_bits(mask), \ ++ nr_cpumask_bits); ++ ++static void sched_init_topology_cpumask(void) ++{ ++ int cpu; ++ cpumask_t *topo; ++ ++ for_each_online_cpu(cpu) { ++ /* take chance to reset time slice for idle tasks */ ++ cpu_rq(cpu)->idle->time_slice = sched_timeslice_ns; ++ ++ topo = per_cpu(sched_cpu_topo_masks, cpu) + 1; ++ ++ bitmap_complement(cpumask_bits(topo), cpumask_bits(cpumask_of(cpu)), ++ nr_cpumask_bits); ++#ifdef CONFIG_SCHED_SMT ++ TOPOLOGY_CPUMASK(smt, topology_sibling_cpumask(cpu), false); ++#endif ++ per_cpu(sd_llc_id, cpu) = cpumask_first(cpu_coregroup_mask(cpu)); ++ per_cpu(sched_cpu_llc_mask, cpu) = topo; ++ TOPOLOGY_CPUMASK(coregroup, cpu_coregroup_mask(cpu), false); ++ ++ TOPOLOGY_CPUMASK(core, topology_core_cpumask(cpu), false); ++ ++ TOPOLOGY_CPUMASK(others, cpu_online_mask, true); ++ ++ per_cpu(sched_cpu_topo_end_mask, cpu) = topo; ++ printk(KERN_INFO "sched: cpu#%02d llc_id = %d, llc_mask idx = %d\n", ++ cpu, per_cpu(sd_llc_id, cpu), ++ (int) (per_cpu(sched_cpu_llc_mask, cpu) - ++ per_cpu(sched_cpu_topo_masks, cpu))); ++ } ++} ++#endif ++ ++void __init sched_init_smp(void) ++{ ++ /* Move init over to a non-isolated CPU */ ++ if (set_cpus_allowed_ptr(current, housekeeping_cpumask(HK_TYPE_DOMAIN)) < 0) ++ BUG(); ++ current->flags &= ~PF_NO_SETAFFINITY; ++ ++ sched_init_topology_cpumask(); ++ ++ sched_smp_initialized = true; ++} ++ ++static int __init migration_init(void) ++{ ++ sched_cpu_starting(smp_processor_id()); ++ return 0; ++} ++early_initcall(migration_init); ++ ++#else ++void __init sched_init_smp(void) ++{ ++ cpu_rq(0)->idle->time_slice = sched_timeslice_ns; ++} ++#endif /* CONFIG_SMP */ ++ ++int in_sched_functions(unsigned long addr) ++{ ++ return in_lock_functions(addr) || ++ (addr >= (unsigned long)__sched_text_start ++ && addr < (unsigned long)__sched_text_end); ++} ++ ++#ifdef CONFIG_CGROUP_SCHED ++/* task group related information */ ++struct task_group { ++ struct cgroup_subsys_state css; ++ ++ struct rcu_head rcu; ++ struct list_head list; ++ ++ struct task_group *parent; ++ struct list_head siblings; ++ struct list_head children; ++#ifdef CONFIG_FAIR_GROUP_SCHED ++ unsigned long shares; ++#endif ++}; ++ ++/* ++ * Default task group. ++ * Every task in system belongs to this group at bootup. ++ */ ++struct task_group root_task_group; ++LIST_HEAD(task_groups); ++ ++/* Cacheline aligned slab cache for task_group */ ++static struct kmem_cache *task_group_cache __ro_after_init; ++#endif /* CONFIG_CGROUP_SCHED */ ++ ++void __init sched_init(void) ++{ ++ int i; ++ struct rq *rq; ++ ++ printk(KERN_INFO "sched/alt: "ALT_SCHED_NAME" CPU Scheduler "ALT_SCHED_VERSION\ ++ " by Alfred Chen.\n"); ++ ++ wait_bit_init(); ++ ++#ifdef CONFIG_SMP ++ for (i = 0; i < SCHED_QUEUE_BITS; i++) ++ cpumask_copy(sched_preempt_mask + i, cpu_present_mask); ++#endif ++ ++#ifdef CONFIG_CGROUP_SCHED ++ task_group_cache = KMEM_CACHE(task_group, 0); ++ ++ list_add(&root_task_group.list, &task_groups); ++ INIT_LIST_HEAD(&root_task_group.children); ++ INIT_LIST_HEAD(&root_task_group.siblings); ++#endif /* CONFIG_CGROUP_SCHED */ ++ for_each_possible_cpu(i) { ++ rq = cpu_rq(i); ++ ++ sched_queue_init(&rq->queue); ++ rq->prio = IDLE_TASK_SCHED_PRIO; ++ rq->skip = NULL; ++ ++ raw_spin_lock_init(&rq->lock); ++ rq->nr_running = rq->nr_uninterruptible = 0; ++ rq->calc_load_active = 0; ++ rq->calc_load_update = jiffies + LOAD_FREQ; ++#ifdef CONFIG_SMP ++ rq->online = false; ++ rq->cpu = i; ++ ++#ifdef CONFIG_SCHED_SMT ++ rq->active_balance = 0; ++#endif ++ ++#ifdef CONFIG_NO_HZ_COMMON ++ INIT_CSD(&rq->nohz_csd, nohz_csd_func, rq); ++#endif ++ rq->balance_callback = &balance_push_callback; ++#ifdef CONFIG_HOTPLUG_CPU ++ rcuwait_init(&rq->hotplug_wait); ++#endif ++#endif /* CONFIG_SMP */ ++ rq->nr_switches = 0; ++ ++ hrtick_rq_init(rq); ++ atomic_set(&rq->nr_iowait, 0); ++ ++ zalloc_cpumask_var_node(&rq->scratch_mask, GFP_KERNEL, cpu_to_node(i)); ++ } ++#ifdef CONFIG_SMP ++ /* Set rq->online for cpu 0 */ ++ cpu_rq(0)->online = true; ++#endif ++ /* ++ * The boot idle thread does lazy MMU switching as well: ++ */ ++ mmgrab(&init_mm); ++ enter_lazy_tlb(&init_mm, current); ++ ++ /* ++ * The idle task doesn't need the kthread struct to function, but it ++ * is dressed up as a per-CPU kthread and thus needs to play the part ++ * if we want to avoid special-casing it in code that deals with per-CPU ++ * kthreads. ++ */ ++ WARN_ON(!set_kthread_struct(current)); ++ ++ /* ++ * Make us the idle thread. Technically, schedule() should not be ++ * called from this thread, however somewhere below it might be, ++ * but because we are the idle thread, we just pick up running again ++ * when this runqueue becomes "idle". ++ */ ++ init_idle(current, smp_processor_id()); ++ ++ calc_load_update = jiffies + LOAD_FREQ; ++ ++#ifdef CONFIG_SMP ++ idle_thread_set_boot_cpu(); ++ balance_push_set(smp_processor_id(), false); ++ ++ sched_init_topology_cpumask_early(); ++#endif /* SMP */ ++ ++ preempt_dynamic_init(); ++} ++ ++#ifdef CONFIG_DEBUG_ATOMIC_SLEEP ++ ++void __might_sleep(const char *file, int line) ++{ ++ unsigned int state = get_current_state(); ++ /* ++ * Blocking primitives will set (and therefore destroy) current->state, ++ * since we will exit with TASK_RUNNING make sure we enter with it, ++ * otherwise we will destroy state. ++ */ ++ WARN_ONCE(state != TASK_RUNNING && current->task_state_change, ++ "do not call blocking ops when !TASK_RUNNING; " ++ "state=%x set at [<%p>] %pS\n", state, ++ (void *)current->task_state_change, ++ (void *)current->task_state_change); ++ ++ __might_resched(file, line, 0); ++} ++EXPORT_SYMBOL(__might_sleep); ++ ++static void print_preempt_disable_ip(int preempt_offset, unsigned long ip) ++{ ++ if (!IS_ENABLED(CONFIG_DEBUG_PREEMPT)) ++ return; ++ ++ if (preempt_count() == preempt_offset) ++ return; ++ ++ pr_err("Preemption disabled at:"); ++ print_ip_sym(KERN_ERR, ip); ++} ++ ++static inline bool resched_offsets_ok(unsigned int offsets) ++{ ++ unsigned int nested = preempt_count(); ++ ++ nested += rcu_preempt_depth() << MIGHT_RESCHED_RCU_SHIFT; ++ ++ return nested == offsets; ++} ++ ++void __might_resched(const char *file, int line, unsigned int offsets) ++{ ++ /* Ratelimiting timestamp: */ ++ static unsigned long prev_jiffy; ++ ++ unsigned long preempt_disable_ip; ++ ++ /* WARN_ON_ONCE() by default, no rate limit required: */ ++ rcu_sleep_check(); ++ ++ if ((resched_offsets_ok(offsets) && !irqs_disabled() && ++ !is_idle_task(current) && !current->non_block_count) || ++ system_state == SYSTEM_BOOTING || system_state > SYSTEM_RUNNING || ++ oops_in_progress) ++ return; ++ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) ++ return; ++ prev_jiffy = jiffies; ++ ++ /* Save this before calling printk(), since that will clobber it: */ ++ preempt_disable_ip = get_preempt_disable_ip(current); ++ ++ pr_err("BUG: sleeping function called from invalid context at %s:%d\n", ++ file, line); ++ pr_err("in_atomic(): %d, irqs_disabled(): %d, non_block: %d, pid: %d, name: %s\n", ++ in_atomic(), irqs_disabled(), current->non_block_count, ++ current->pid, current->comm); ++ pr_err("preempt_count: %x, expected: %x\n", preempt_count(), ++ offsets & MIGHT_RESCHED_PREEMPT_MASK); ++ ++ if (IS_ENABLED(CONFIG_PREEMPT_RCU)) { ++ pr_err("RCU nest depth: %d, expected: %u\n", ++ rcu_preempt_depth(), offsets >> MIGHT_RESCHED_RCU_SHIFT); ++ } ++ ++ if (task_stack_end_corrupted(current)) ++ pr_emerg("Thread overran stack, or stack corrupted\n"); ++ ++ debug_show_held_locks(current); ++ if (irqs_disabled()) ++ print_irqtrace_events(current); ++ ++ print_preempt_disable_ip(offsets & MIGHT_RESCHED_PREEMPT_MASK, ++ preempt_disable_ip); ++ ++ dump_stack(); ++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); ++} ++EXPORT_SYMBOL(__might_resched); ++ ++void __cant_sleep(const char *file, int line, int preempt_offset) ++{ ++ static unsigned long prev_jiffy; ++ ++ if (irqs_disabled()) ++ return; ++ ++ if (!IS_ENABLED(CONFIG_PREEMPT_COUNT)) ++ return; ++ ++ if (preempt_count() > preempt_offset) ++ return; ++ ++ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) ++ return; ++ prev_jiffy = jiffies; ++ ++ printk(KERN_ERR "BUG: assuming atomic context at %s:%d\n", file, line); ++ printk(KERN_ERR "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", ++ in_atomic(), irqs_disabled(), ++ current->pid, current->comm); ++ ++ debug_show_held_locks(current); ++ dump_stack(); ++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); ++} ++EXPORT_SYMBOL_GPL(__cant_sleep); ++ ++#ifdef CONFIG_SMP ++void __cant_migrate(const char *file, int line) ++{ ++ static unsigned long prev_jiffy; ++ ++ if (irqs_disabled()) ++ return; ++ ++ if (is_migration_disabled(current)) ++ return; ++ ++ if (!IS_ENABLED(CONFIG_PREEMPT_COUNT)) ++ return; ++ ++ if (preempt_count() > 0) ++ return; ++ ++ if (current->migration_flags & MDF_FORCE_ENABLED) ++ return; ++ ++ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) ++ return; ++ prev_jiffy = jiffies; ++ ++ pr_err("BUG: assuming non migratable context at %s:%d\n", file, line); ++ pr_err("in_atomic(): %d, irqs_disabled(): %d, migration_disabled() %u pid: %d, name: %s\n", ++ in_atomic(), irqs_disabled(), is_migration_disabled(current), ++ current->pid, current->comm); ++ ++ debug_show_held_locks(current); ++ dump_stack(); ++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); ++} ++EXPORT_SYMBOL_GPL(__cant_migrate); ++#endif ++#endif ++ ++#ifdef CONFIG_MAGIC_SYSRQ ++void normalize_rt_tasks(void) ++{ ++ struct task_struct *g, *p; ++ struct sched_attr attr = { ++ .sched_policy = SCHED_NORMAL, ++ }; ++ ++ read_lock(&tasklist_lock); ++ for_each_process_thread(g, p) { ++ /* ++ * Only normalize user tasks: ++ */ ++ if (p->flags & PF_KTHREAD) ++ continue; ++ ++ schedstat_set(p->stats.wait_start, 0); ++ schedstat_set(p->stats.sleep_start, 0); ++ schedstat_set(p->stats.block_start, 0); ++ ++ if (!rt_task(p)) { ++ /* ++ * Renice negative nice level userspace ++ * tasks back to 0: ++ */ ++ if (task_nice(p) < 0) ++ set_user_nice(p, 0); ++ continue; ++ } ++ ++ __sched_setscheduler(p, &attr, false, false); ++ } ++ read_unlock(&tasklist_lock); ++} ++#endif /* CONFIG_MAGIC_SYSRQ */ ++ ++#if defined(CONFIG_KGDB_KDB) ++/* ++ * These functions are only useful for kdb. ++ * ++ * They can only be called when the whole system has been ++ * stopped - every CPU needs to be quiescent, and no scheduling ++ * activity can take place. Using them for anything else would ++ * be a serious bug, and as a result, they aren't even visible ++ * under any other configuration. ++ */ ++ ++/** ++ * curr_task - return the current task for a given CPU. ++ * @cpu: the processor in question. ++ * ++ * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! ++ * ++ * Return: The current task for @cpu. ++ */ ++struct task_struct *curr_task(int cpu) ++{ ++ return cpu_curr(cpu); ++} ++ ++#endif /* defined(CONFIG_KGDB_KDB) */ ++ ++#ifdef CONFIG_CGROUP_SCHED ++static void sched_free_group(struct task_group *tg) ++{ ++ kmem_cache_free(task_group_cache, tg); ++} ++ ++static void sched_free_group_rcu(struct rcu_head *rhp) ++{ ++ sched_free_group(container_of(rhp, struct task_group, rcu)); ++} ++ ++static void sched_unregister_group(struct task_group *tg) ++{ ++ /* ++ * We have to wait for yet another RCU grace period to expire, as ++ * print_cfs_stats() might run concurrently. ++ */ ++ call_rcu(&tg->rcu, sched_free_group_rcu); ++} ++ ++/* allocate runqueue etc for a new task group */ ++struct task_group *sched_create_group(struct task_group *parent) ++{ ++ struct task_group *tg; ++ ++ tg = kmem_cache_alloc(task_group_cache, GFP_KERNEL | __GFP_ZERO); ++ if (!tg) ++ return ERR_PTR(-ENOMEM); ++ ++ return tg; ++} ++ ++void sched_online_group(struct task_group *tg, struct task_group *parent) ++{ ++} ++ ++/* rcu callback to free various structures associated with a task group */ ++static void sched_unregister_group_rcu(struct rcu_head *rhp) ++{ ++ /* Now it should be safe to free those cfs_rqs: */ ++ sched_unregister_group(container_of(rhp, struct task_group, rcu)); ++} ++ ++void sched_destroy_group(struct task_group *tg) ++{ ++ /* Wait for possible concurrent references to cfs_rqs complete: */ ++ call_rcu(&tg->rcu, sched_unregister_group_rcu); ++} ++ ++void sched_release_group(struct task_group *tg) ++{ ++} ++ ++static inline struct task_group *css_tg(struct cgroup_subsys_state *css) ++{ ++ return css ? container_of(css, struct task_group, css) : NULL; ++} ++ ++static struct cgroup_subsys_state * ++cpu_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) ++{ ++ struct task_group *parent = css_tg(parent_css); ++ struct task_group *tg; ++ ++ if (!parent) { ++ /* This is early initialization for the top cgroup */ ++ return &root_task_group.css; ++ } ++ ++ tg = sched_create_group(parent); ++ if (IS_ERR(tg)) ++ return ERR_PTR(-ENOMEM); ++ return &tg->css; ++} ++ ++/* Expose task group only after completing cgroup initialization */ ++static int cpu_cgroup_css_online(struct cgroup_subsys_state *css) ++{ ++ struct task_group *tg = css_tg(css); ++ struct task_group *parent = css_tg(css->parent); ++ ++ if (parent) ++ sched_online_group(tg, parent); ++ return 0; ++} ++ ++static void cpu_cgroup_css_released(struct cgroup_subsys_state *css) ++{ ++ struct task_group *tg = css_tg(css); ++ ++ sched_release_group(tg); ++} ++ ++static void cpu_cgroup_css_free(struct cgroup_subsys_state *css) ++{ ++ struct task_group *tg = css_tg(css); ++ ++ /* ++ * Relies on the RCU grace period between css_released() and this. ++ */ ++ sched_unregister_group(tg); ++} ++ ++#ifdef CONFIG_RT_GROUP_SCHED ++static int cpu_cgroup_can_attach(struct cgroup_taskset *tset) ++{ ++ return 0; ++} ++#endif ++ ++static void cpu_cgroup_attach(struct cgroup_taskset *tset) ++{ ++} ++ ++#ifdef CONFIG_FAIR_GROUP_SCHED ++static DEFINE_MUTEX(shares_mutex); ++ ++int sched_group_set_shares(struct task_group *tg, unsigned long shares) ++{ ++ /* ++ * We can't change the weight of the root cgroup. ++ */ ++ if (&root_task_group == tg) ++ return -EINVAL; ++ ++ shares = clamp(shares, scale_load(MIN_SHARES), scale_load(MAX_SHARES)); ++ ++ mutex_lock(&shares_mutex); ++ if (tg->shares == shares) ++ goto done; ++ ++ tg->shares = shares; ++done: ++ mutex_unlock(&shares_mutex); ++ return 0; ++} ++ ++static int cpu_shares_write_u64(struct cgroup_subsys_state *css, ++ struct cftype *cftype, u64 shareval) ++{ ++ if (shareval > scale_load_down(ULONG_MAX)) ++ shareval = MAX_SHARES; ++ return sched_group_set_shares(css_tg(css), scale_load(shareval)); ++} ++ ++static u64 cpu_shares_read_u64(struct cgroup_subsys_state *css, ++ struct cftype *cft) ++{ ++ struct task_group *tg = css_tg(css); ++ ++ return (u64) scale_load_down(tg->shares); ++} ++#endif ++ ++static struct cftype cpu_legacy_files[] = { ++#ifdef CONFIG_FAIR_GROUP_SCHED ++ { ++ .name = "shares", ++ .read_u64 = cpu_shares_read_u64, ++ .write_u64 = cpu_shares_write_u64, ++ }, ++#endif ++ { } /* Terminate */ ++}; ++ ++ ++static struct cftype cpu_files[] = { ++ { } /* terminate */ ++}; ++ ++static int cpu_extra_stat_show(struct seq_file *sf, ++ struct cgroup_subsys_state *css) ++{ ++ return 0; ++} ++ ++struct cgroup_subsys cpu_cgrp_subsys = { ++ .css_alloc = cpu_cgroup_css_alloc, ++ .css_online = cpu_cgroup_css_online, ++ .css_released = cpu_cgroup_css_released, ++ .css_free = cpu_cgroup_css_free, ++ .css_extra_stat_show = cpu_extra_stat_show, ++#ifdef CONFIG_RT_GROUP_SCHED ++ .can_attach = cpu_cgroup_can_attach, ++#endif ++ .attach = cpu_cgroup_attach, ++ .legacy_cftypes = cpu_files, ++ .legacy_cftypes = cpu_legacy_files, ++ .dfl_cftypes = cpu_files, ++ .early_init = true, ++ .threaded = true, ++}; ++#endif /* CONFIG_CGROUP_SCHED */ ++ ++#undef CREATE_TRACE_POINTS ++ ++#ifdef CONFIG_SCHED_MM_CID ++ ++# ++/* ++ * @cid_lock: Guarantee forward-progress of cid allocation. ++ * ++ * Concurrency ID allocation within a bitmap is mostly lock-free. The cid_lock ++ * is only used when contention is detected by the lock-free allocation so ++ * forward progress can be guaranteed. ++ */ ++DEFINE_RAW_SPINLOCK(cid_lock); ++ ++/* ++ * @use_cid_lock: Select cid allocation behavior: lock-free vs spinlock. ++ * ++ * When @use_cid_lock is 0, the cid allocation is lock-free. When contention is ++ * detected, it is set to 1 to ensure that all newly coming allocations are ++ * serialized by @cid_lock until the allocation which detected contention ++ * completes and sets @use_cid_lock back to 0. This guarantees forward progress ++ * of a cid allocation. ++ */ ++int use_cid_lock; ++ ++/* ++ * mm_cid remote-clear implements a lock-free algorithm to clear per-mm/cpu cid ++ * concurrently with respect to the execution of the source runqueue context ++ * switch. ++ * ++ * There is one basic properties we want to guarantee here: ++ * ++ * (1) Remote-clear should _never_ mark a per-cpu cid UNSET when it is actively ++ * used by a task. That would lead to concurrent allocation of the cid and ++ * userspace corruption. ++ * ++ * Provide this guarantee by introducing a Dekker memory ordering to guarantee ++ * that a pair of loads observe at least one of a pair of stores, which can be ++ * shown as: ++ * ++ * X = Y = 0 ++ * ++ * w[X]=1 w[Y]=1 ++ * MB MB ++ * r[Y]=y r[X]=x ++ * ++ * Which guarantees that x==0 && y==0 is impossible. But rather than using ++ * values 0 and 1, this algorithm cares about specific state transitions of the ++ * runqueue current task (as updated by the scheduler context switch), and the ++ * per-mm/cpu cid value. ++ * ++ * Let's introduce task (Y) which has task->mm == mm and task (N) which has ++ * task->mm != mm for the rest of the discussion. There are two scheduler state ++ * transitions on context switch we care about: ++ * ++ * (TSA) Store to rq->curr with transition from (N) to (Y) ++ * ++ * (TSB) Store to rq->curr with transition from (Y) to (N) ++ * ++ * On the remote-clear side, there is one transition we care about: ++ * ++ * (TMA) cmpxchg to *pcpu_cid to set the LAZY flag ++ * ++ * There is also a transition to UNSET state which can be performed from all ++ * sides (scheduler, remote-clear). It is always performed with a cmpxchg which ++ * guarantees that only a single thread will succeed: ++ * ++ * (TMB) cmpxchg to *pcpu_cid to mark UNSET ++ * ++ * Just to be clear, what we do _not_ want to happen is a transition to UNSET ++ * when a thread is actively using the cid (property (1)). ++ * ++ * Let's looks at the relevant combinations of TSA/TSB, and TMA transitions. ++ * ++ * Scenario A) (TSA)+(TMA) (from next task perspective) ++ * ++ * CPU0 CPU1 ++ * ++ * Context switch CS-1 Remote-clear ++ * - store to rq->curr: (N)->(Y) (TSA) - cmpxchg to *pcpu_id to LAZY (TMA) ++ * (implied barrier after cmpxchg) ++ * - switch_mm_cid() ++ * - memory barrier (see switch_mm_cid() ++ * comment explaining how this barrier ++ * is combined with other scheduler ++ * barriers) ++ * - mm_cid_get (next) ++ * - READ_ONCE(*pcpu_cid) - rcu_dereference(src_rq->curr) ++ * ++ * This Dekker ensures that either task (Y) is observed by the ++ * rcu_dereference() or the LAZY flag is observed by READ_ONCE(), or both are ++ * observed. ++ * ++ * If task (Y) store is observed by rcu_dereference(), it means that there is ++ * still an active task on the cpu. Remote-clear will therefore not transition ++ * to UNSET, which fulfills property (1). ++ * ++ * If task (Y) is not observed, but the lazy flag is observed by READ_ONCE(), ++ * it will move its state to UNSET, which clears the percpu cid perhaps ++ * uselessly (which is not an issue for correctness). Because task (Y) is not ++ * observed, CPU1 can move ahead to set the state to UNSET. Because moving ++ * state to UNSET is done with a cmpxchg expecting that the old state has the ++ * LAZY flag set, only one thread will successfully UNSET. ++ * ++ * If both states (LAZY flag and task (Y)) are observed, the thread on CPU0 ++ * will observe the LAZY flag and transition to UNSET (perhaps uselessly), and ++ * CPU1 will observe task (Y) and do nothing more, which is fine. ++ * ++ * What we are effectively preventing with this Dekker is a scenario where ++ * neither LAZY flag nor store (Y) are observed, which would fail property (1) ++ * because this would UNSET a cid which is actively used. ++ */ ++ ++void sched_mm_cid_migrate_from(struct task_struct *t) ++{ ++ t->migrate_from_cpu = task_cpu(t); ++} ++ ++static ++int __sched_mm_cid_migrate_from_fetch_cid(struct rq *src_rq, ++ struct task_struct *t, ++ struct mm_cid *src_pcpu_cid) ++{ ++ struct mm_struct *mm = t->mm; ++ struct task_struct *src_task; ++ int src_cid, last_mm_cid; ++ ++ if (!mm) ++ return -1; ++ ++ last_mm_cid = t->last_mm_cid; ++ /* ++ * If the migrated task has no last cid, or if the current ++ * task on src rq uses the cid, it means the source cid does not need ++ * to be moved to the destination cpu. ++ */ ++ if (last_mm_cid == -1) ++ return -1; ++ src_cid = READ_ONCE(src_pcpu_cid->cid); ++ if (!mm_cid_is_valid(src_cid) || last_mm_cid != src_cid) ++ return -1; ++ ++ /* ++ * If we observe an active task using the mm on this rq, it means we ++ * are not the last task to be migrated from this cpu for this mm, so ++ * there is no need to move src_cid to the destination cpu. ++ */ ++ rcu_read_lock(); ++ src_task = rcu_dereference(src_rq->curr); ++ if (READ_ONCE(src_task->mm_cid_active) && src_task->mm == mm) { ++ rcu_read_unlock(); ++ t->last_mm_cid = -1; ++ return -1; ++ } ++ rcu_read_unlock(); ++ ++ return src_cid; ++} ++ ++static ++int __sched_mm_cid_migrate_from_try_steal_cid(struct rq *src_rq, ++ struct task_struct *t, ++ struct mm_cid *src_pcpu_cid, ++ int src_cid) ++{ ++ struct task_struct *src_task; ++ struct mm_struct *mm = t->mm; ++ int lazy_cid; ++ ++ if (src_cid == -1) ++ return -1; ++ ++ /* ++ * Attempt to clear the source cpu cid to move it to the destination ++ * cpu. ++ */ ++ lazy_cid = mm_cid_set_lazy_put(src_cid); ++ if (!try_cmpxchg(&src_pcpu_cid->cid, &src_cid, lazy_cid)) ++ return -1; ++ ++ /* ++ * The implicit barrier after cmpxchg per-mm/cpu cid before loading ++ * rq->curr->mm matches the scheduler barrier in context_switch() ++ * between store to rq->curr and load of prev and next task's ++ * per-mm/cpu cid. ++ * ++ * The implicit barrier after cmpxchg per-mm/cpu cid before loading ++ * rq->curr->mm_cid_active matches the barrier in ++ * sched_mm_cid_exit_signals(), sched_mm_cid_before_execve(), and ++ * sched_mm_cid_after_execve() between store to t->mm_cid_active and ++ * load of per-mm/cpu cid. ++ */ ++ ++ /* ++ * If we observe an active task using the mm on this rq after setting ++ * the lazy-put flag, this task will be responsible for transitioning ++ * from lazy-put flag set to MM_CID_UNSET. ++ */ ++ scoped_guard (rcu) { ++ src_task = rcu_dereference(src_rq->curr); ++ if (READ_ONCE(src_task->mm_cid_active) && src_task->mm == mm) { ++ rcu_read_unlock(); ++ /* ++ * We observed an active task for this mm, there is therefore ++ * no point in moving this cid to the destination cpu. ++ */ ++ t->last_mm_cid = -1; ++ return -1; ++ } ++ } ++ ++ /* ++ * The src_cid is unused, so it can be unset. ++ */ ++ if (!try_cmpxchg(&src_pcpu_cid->cid, &lazy_cid, MM_CID_UNSET)) ++ return -1; ++ return src_cid; ++} ++ ++/* ++ * Migration to dst cpu. Called with dst_rq lock held. ++ * Interrupts are disabled, which keeps the window of cid ownership without the ++ * source rq lock held small. ++ */ ++void sched_mm_cid_migrate_to(struct rq *dst_rq, struct task_struct *t, int src_cpu) ++{ ++ struct mm_cid *src_pcpu_cid, *dst_pcpu_cid; ++ struct mm_struct *mm = t->mm; ++ int src_cid, dst_cid; ++ struct rq *src_rq; ++ ++ lockdep_assert_rq_held(dst_rq); ++ ++ if (!mm) ++ return; ++ if (src_cpu == -1) { ++ t->last_mm_cid = -1; ++ return; ++ } ++ /* ++ * Move the src cid if the dst cid is unset. This keeps id ++ * allocation closest to 0 in cases where few threads migrate around ++ * many cpus. ++ * ++ * If destination cid is already set, we may have to just clear ++ * the src cid to ensure compactness in frequent migrations ++ * scenarios. ++ * ++ * It is not useful to clear the src cid when the number of threads is ++ * greater or equal to the number of allowed cpus, because user-space ++ * can expect that the number of allowed cids can reach the number of ++ * allowed cpus. ++ */ ++ dst_pcpu_cid = per_cpu_ptr(mm->pcpu_cid, cpu_of(dst_rq)); ++ dst_cid = READ_ONCE(dst_pcpu_cid->cid); ++ if (!mm_cid_is_unset(dst_cid) && ++ atomic_read(&mm->mm_users) >= t->nr_cpus_allowed) ++ return; ++ src_pcpu_cid = per_cpu_ptr(mm->pcpu_cid, src_cpu); ++ src_rq = cpu_rq(src_cpu); ++ src_cid = __sched_mm_cid_migrate_from_fetch_cid(src_rq, t, src_pcpu_cid); ++ if (src_cid == -1) ++ return; ++ src_cid = __sched_mm_cid_migrate_from_try_steal_cid(src_rq, t, src_pcpu_cid, ++ src_cid); ++ if (src_cid == -1) ++ return; ++ if (!mm_cid_is_unset(dst_cid)) { ++ __mm_cid_put(mm, src_cid); ++ return; ++ } ++ /* Move src_cid to dst cpu. */ ++ mm_cid_snapshot_time(dst_rq, mm); ++ WRITE_ONCE(dst_pcpu_cid->cid, src_cid); ++} ++ ++static void sched_mm_cid_remote_clear(struct mm_struct *mm, struct mm_cid *pcpu_cid, ++ int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ struct task_struct *t; ++ int cid, lazy_cid; ++ ++ cid = READ_ONCE(pcpu_cid->cid); ++ if (!mm_cid_is_valid(cid)) ++ return; ++ ++ /* ++ * Clear the cpu cid if it is set to keep cid allocation compact. If ++ * there happens to be other tasks left on the source cpu using this ++ * mm, the next task using this mm will reallocate its cid on context ++ * switch. ++ */ ++ lazy_cid = mm_cid_set_lazy_put(cid); ++ if (!try_cmpxchg(&pcpu_cid->cid, &cid, lazy_cid)) ++ return; ++ ++ /* ++ * The implicit barrier after cmpxchg per-mm/cpu cid before loading ++ * rq->curr->mm matches the scheduler barrier in context_switch() ++ * between store to rq->curr and load of prev and next task's ++ * per-mm/cpu cid. ++ * ++ * The implicit barrier after cmpxchg per-mm/cpu cid before loading ++ * rq->curr->mm_cid_active matches the barrier in ++ * sched_mm_cid_exit_signals(), sched_mm_cid_before_execve(), and ++ * sched_mm_cid_after_execve() between store to t->mm_cid_active and ++ * load of per-mm/cpu cid. ++ */ ++ ++ /* ++ * If we observe an active task using the mm on this rq after setting ++ * the lazy-put flag, that task will be responsible for transitioning ++ * from lazy-put flag set to MM_CID_UNSET. ++ */ ++ scoped_guard (rcu) { ++ t = rcu_dereference(rq->curr); ++ if (READ_ONCE(t->mm_cid_active) && t->mm == mm) ++ return; ++ } ++ ++ /* ++ * The cid is unused, so it can be unset. ++ * Disable interrupts to keep the window of cid ownership without rq ++ * lock small. ++ */ ++ scoped_guard (irqsave) { ++ if (try_cmpxchg(&pcpu_cid->cid, &lazy_cid, MM_CID_UNSET)) ++ __mm_cid_put(mm, cid); ++ } ++} ++ ++static void sched_mm_cid_remote_clear_old(struct mm_struct *mm, int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ struct mm_cid *pcpu_cid; ++ struct task_struct *curr; ++ u64 rq_clock; ++ ++ /* ++ * rq->clock load is racy on 32-bit but one spurious clear once in a ++ * while is irrelevant. ++ */ ++ rq_clock = READ_ONCE(rq->clock); ++ pcpu_cid = per_cpu_ptr(mm->pcpu_cid, cpu); ++ ++ /* ++ * In order to take care of infrequently scheduled tasks, bump the time ++ * snapshot associated with this cid if an active task using the mm is ++ * observed on this rq. ++ */ ++ scoped_guard (rcu) { ++ curr = rcu_dereference(rq->curr); ++ if (READ_ONCE(curr->mm_cid_active) && curr->mm == mm) { ++ WRITE_ONCE(pcpu_cid->time, rq_clock); ++ return; ++ } ++ } ++ ++ if (rq_clock < pcpu_cid->time + SCHED_MM_CID_PERIOD_NS) ++ return; ++ sched_mm_cid_remote_clear(mm, pcpu_cid, cpu); ++} ++ ++static void sched_mm_cid_remote_clear_weight(struct mm_struct *mm, int cpu, ++ int weight) ++{ ++ struct mm_cid *pcpu_cid; ++ int cid; ++ ++ pcpu_cid = per_cpu_ptr(mm->pcpu_cid, cpu); ++ cid = READ_ONCE(pcpu_cid->cid); ++ if (!mm_cid_is_valid(cid) || cid < weight) ++ return; ++ sched_mm_cid_remote_clear(mm, pcpu_cid, cpu); ++} ++ ++static void task_mm_cid_work(struct callback_head *work) ++{ ++ unsigned long now = jiffies, old_scan, next_scan; ++ struct task_struct *t = current; ++ struct cpumask *cidmask; ++ struct mm_struct *mm; ++ int weight, cpu; ++ ++ SCHED_WARN_ON(t != container_of(work, struct task_struct, cid_work)); ++ ++ work->next = work; /* Prevent double-add */ ++ if (t->flags & PF_EXITING) ++ return; ++ mm = t->mm; ++ if (!mm) ++ return; ++ old_scan = READ_ONCE(mm->mm_cid_next_scan); ++ next_scan = now + msecs_to_jiffies(MM_CID_SCAN_DELAY); ++ if (!old_scan) { ++ unsigned long res; ++ ++ res = cmpxchg(&mm->mm_cid_next_scan, old_scan, next_scan); ++ if (res != old_scan) ++ old_scan = res; ++ else ++ old_scan = next_scan; ++ } ++ if (time_before(now, old_scan)) ++ return; ++ if (!try_cmpxchg(&mm->mm_cid_next_scan, &old_scan, next_scan)) ++ return; ++ cidmask = mm_cidmask(mm); ++ /* Clear cids that were not recently used. */ ++ for_each_possible_cpu(cpu) ++ sched_mm_cid_remote_clear_old(mm, cpu); ++ weight = cpumask_weight(cidmask); ++ /* ++ * Clear cids that are greater or equal to the cidmask weight to ++ * recompact it. ++ */ ++ for_each_possible_cpu(cpu) ++ sched_mm_cid_remote_clear_weight(mm, cpu, weight); ++} ++ ++void init_sched_mm_cid(struct task_struct *t) ++{ ++ struct mm_struct *mm = t->mm; ++ int mm_users = 0; ++ ++ if (mm) { ++ mm_users = atomic_read(&mm->mm_users); ++ if (mm_users == 1) ++ mm->mm_cid_next_scan = jiffies + msecs_to_jiffies(MM_CID_SCAN_DELAY); ++ } ++ t->cid_work.next = &t->cid_work; /* Protect against double add */ ++ init_task_work(&t->cid_work, task_mm_cid_work); ++} ++ ++void task_tick_mm_cid(struct rq *rq, struct task_struct *curr) ++{ ++ struct callback_head *work = &curr->cid_work; ++ unsigned long now = jiffies; ++ ++ if (!curr->mm || (curr->flags & (PF_EXITING | PF_KTHREAD)) || ++ work->next != work) ++ return; ++ if (time_before(now, READ_ONCE(curr->mm->mm_cid_next_scan))) ++ return; ++ task_work_add(curr, work, TWA_RESUME); ++} ++ ++void sched_mm_cid_exit_signals(struct task_struct *t) ++{ ++ struct mm_struct *mm = t->mm; ++ struct rq *rq; ++ ++ if (!mm) ++ return; ++ ++ preempt_disable(); ++ rq = this_rq(); ++ guard(rq_lock_irqsave)(rq); ++ preempt_enable_no_resched(); /* holding spinlock */ ++ WRITE_ONCE(t->mm_cid_active, 0); ++ /* ++ * Store t->mm_cid_active before loading per-mm/cpu cid. ++ * Matches barrier in sched_mm_cid_remote_clear_old(). ++ */ ++ smp_mb(); ++ mm_cid_put(mm); ++ t->last_mm_cid = t->mm_cid = -1; ++} ++ ++void sched_mm_cid_before_execve(struct task_struct *t) ++{ ++ struct mm_struct *mm = t->mm; ++ struct rq *rq; ++ ++ if (!mm) ++ return; ++ ++ preempt_disable(); ++ rq = this_rq(); ++ guard(rq_lock_irqsave)(rq); ++ preempt_enable_no_resched(); /* holding spinlock */ ++ WRITE_ONCE(t->mm_cid_active, 0); ++ /* ++ * Store t->mm_cid_active before loading per-mm/cpu cid. ++ * Matches barrier in sched_mm_cid_remote_clear_old(). ++ */ ++ smp_mb(); ++ mm_cid_put(mm); ++ t->last_mm_cid = t->mm_cid = -1; ++} ++ ++void sched_mm_cid_after_execve(struct task_struct *t) ++{ ++ struct mm_struct *mm = t->mm; ++ struct rq *rq; ++ ++ if (!mm) ++ return; ++ ++ preempt_disable(); ++ rq = this_rq(); ++ scoped_guard (rq_lock_irqsave, rq) { ++ preempt_enable_no_resched(); /* holding spinlock */ ++ WRITE_ONCE(t->mm_cid_active, 1); ++ /* ++ * Store t->mm_cid_active before loading per-mm/cpu cid. ++ * Matches barrier in sched_mm_cid_remote_clear_old(). ++ */ ++ smp_mb(); ++ t->last_mm_cid = t->mm_cid = mm_cid_get(rq, mm); ++ } ++ rseq_set_notify_resume(t); ++} ++ ++void sched_mm_cid_fork(struct task_struct *t) ++{ ++ WARN_ON_ONCE(!t->mm || t->mm_cid != -1); ++ t->mm_cid_active = 1; ++} ++#endif +diff --git a/kernel/sched/alt_debug.c b/kernel/sched/alt_debug.c +new file mode 100644 +index 000000000000..1212a031700e +--- /dev/null ++++ b/kernel/sched/alt_debug.c +@@ -0,0 +1,31 @@ ++/* ++ * kernel/sched/alt_debug.c ++ * ++ * Print the alt scheduler debugging details ++ * ++ * Author: Alfred Chen ++ * Date : 2020 ++ */ ++#include "sched.h" ++ ++/* ++ * This allows printing both to /proc/sched_debug and ++ * to the console ++ */ ++#define SEQ_printf(m, x...) \ ++ do { \ ++ if (m) \ ++ seq_printf(m, x); \ ++ else \ ++ pr_cont(x); \ ++ } while (0) ++ ++void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns, ++ struct seq_file *m) ++{ ++ SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, task_pid_nr_ns(p, ns), ++ get_nr_threads(p)); ++} ++ ++void proc_sched_set_task(struct task_struct *p) ++{} +diff --git a/kernel/sched/alt_sched.h b/kernel/sched/alt_sched.h +new file mode 100644 +index 000000000000..1a4dab2b2bb5 +--- /dev/null ++++ b/kernel/sched/alt_sched.h +@@ -0,0 +1,921 @@ ++#ifndef ALT_SCHED_H ++#define ALT_SCHED_H ++ ++#include <linux/context_tracking.h> ++#include <linux/profile.h> ++#include <linux/stop_machine.h> ++#include <linux/syscalls.h> ++#include <linux/tick.h> ++ ++#include <trace/events/power.h> ++#include <trace/events/sched.h> ++ ++#include "../workqueue_internal.h" ++ ++#include "cpupri.h" ++ ++#define MIN_SCHED_NORMAL_PRIO (32) ++/* ++ * levels: RT(0-24), reserved(25-31), NORMAL(32-63), cpu idle task(64) ++ * ++ * -- BMQ -- ++ * NORMAL: (lower boost range 12, NICE_WIDTH 40, higher boost range 12) / 2 ++ * -- PDS -- ++ * NORMAL: SCHED_EDGE_DELTA + ((NICE_WIDTH 40) / 2) ++ */ ++#define SCHED_LEVELS (64 + 1) ++ ++#define IDLE_TASK_SCHED_PRIO (SCHED_LEVELS - 1) ++ ++#ifdef CONFIG_SCHED_DEBUG ++# define SCHED_WARN_ON(x) WARN_ONCE(x, #x) ++extern void resched_latency_warn(int cpu, u64 latency); ++#else ++# define SCHED_WARN_ON(x) ({ (void)(x), 0; }) ++static inline void resched_latency_warn(int cpu, u64 latency) {} ++#endif ++ ++/* ++ * Increase resolution of nice-level calculations for 64-bit architectures. ++ * The extra resolution improves shares distribution and load balancing of ++ * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup ++ * hierarchies, especially on larger systems. This is not a user-visible change ++ * and does not change the user-interface for setting shares/weights. ++ * ++ * We increase resolution only if we have enough bits to allow this increased ++ * resolution (i.e. 64-bit). The costs for increasing resolution when 32-bit ++ * are pretty high and the returns do not justify the increased costs. ++ * ++ * Really only required when CONFIG_FAIR_GROUP_SCHED=y is also set, but to ++ * increase coverage and consistency always enable it on 64-bit platforms. ++ */ ++#ifdef CONFIG_64BIT ++# define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT) ++# define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT) ++# define scale_load_down(w) \ ++({ \ ++ unsigned long __w = (w); \ ++ if (__w) \ ++ __w = max(2UL, __w >> SCHED_FIXEDPOINT_SHIFT); \ ++ __w; \ ++}) ++#else ++# define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT) ++# define scale_load(w) (w) ++# define scale_load_down(w) (w) ++#endif ++ ++#ifdef CONFIG_FAIR_GROUP_SCHED ++#define ROOT_TASK_GROUP_LOAD NICE_0_LOAD ++ ++/* ++ * A weight of 0 or 1 can cause arithmetics problems. ++ * A weight of a cfs_rq is the sum of weights of which entities ++ * are queued on this cfs_rq, so a weight of a entity should not be ++ * too large, so as the shares value of a task group. ++ * (The default weight is 1024 - so there's no practical ++ * limitation from this.) ++ */ ++#define MIN_SHARES (1UL << 1) ++#define MAX_SHARES (1UL << 18) ++#endif ++ ++/* ++ * Tunables that become constants when CONFIG_SCHED_DEBUG is off: ++ */ ++#ifdef CONFIG_SCHED_DEBUG ++# define const_debug __read_mostly ++#else ++# define const_debug const ++#endif ++ ++/* task_struct::on_rq states: */ ++#define TASK_ON_RQ_QUEUED 1 ++#define TASK_ON_RQ_MIGRATING 2 ++ ++static inline int task_on_rq_queued(struct task_struct *p) ++{ ++ return p->on_rq == TASK_ON_RQ_QUEUED; ++} ++ ++static inline int task_on_rq_migrating(struct task_struct *p) ++{ ++ return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING; ++} ++ ++/* Wake flags. The first three directly map to some SD flag value */ ++#define WF_EXEC 0x02 /* Wakeup after exec; maps to SD_BALANCE_EXEC */ ++#define WF_FORK 0x04 /* Wakeup after fork; maps to SD_BALANCE_FORK */ ++#define WF_TTWU 0x08 /* Wakeup; maps to SD_BALANCE_WAKE */ ++ ++#define WF_SYNC 0x10 /* Waker goes to sleep after wakeup */ ++#define WF_MIGRATED 0x20 /* Internal use, task got migrated */ ++#define WF_CURRENT_CPU 0x40 /* Prefer to move the wakee to the current CPU. */ ++ ++#ifdef CONFIG_SMP ++static_assert(WF_EXEC == SD_BALANCE_EXEC); ++static_assert(WF_FORK == SD_BALANCE_FORK); ++static_assert(WF_TTWU == SD_BALANCE_WAKE); ++#endif ++ ++#define SCHED_QUEUE_BITS (SCHED_LEVELS - 1) ++ ++struct sched_queue { ++ DECLARE_BITMAP(bitmap, SCHED_QUEUE_BITS); ++ struct list_head heads[SCHED_LEVELS]; ++}; ++ ++struct rq; ++struct cpuidle_state; ++ ++struct balance_callback { ++ struct balance_callback *next; ++ void (*func)(struct rq *rq); ++}; ++ ++/* ++ * This is the main, per-CPU runqueue data structure. ++ * This data should only be modified by the local cpu. ++ */ ++struct rq { ++ /* runqueue lock: */ ++ raw_spinlock_t lock; ++ ++ struct task_struct __rcu *curr; ++ struct task_struct *idle; ++ struct task_struct *stop; ++ struct task_struct *skip; ++ struct mm_struct *prev_mm; ++ ++ struct sched_queue queue; ++#ifdef CONFIG_SCHED_PDS ++ u64 time_edge; ++#endif ++ unsigned long prio; ++ ++ /* switch count */ ++ u64 nr_switches; ++ ++ atomic_t nr_iowait; ++ ++#ifdef CONFIG_SCHED_DEBUG ++ u64 last_seen_need_resched_ns; ++ int ticks_without_resched; ++#endif ++ ++#ifdef CONFIG_MEMBARRIER ++ int membarrier_state; ++#endif ++ ++#ifdef CONFIG_SMP ++ int cpu; /* cpu of this runqueue */ ++ bool online; ++ ++ unsigned int ttwu_pending; ++ unsigned char nohz_idle_balance; ++ unsigned char idle_balance; ++ ++#ifdef CONFIG_HAVE_SCHED_AVG_IRQ ++ struct sched_avg avg_irq; ++#endif ++ ++#ifdef CONFIG_SCHED_SMT ++ int active_balance; ++ struct cpu_stop_work active_balance_work; ++#endif ++ struct balance_callback *balance_callback; ++#ifdef CONFIG_HOTPLUG_CPU ++ struct rcuwait hotplug_wait; ++#endif ++ unsigned int nr_pinned; ++ ++#endif /* CONFIG_SMP */ ++#ifdef CONFIG_IRQ_TIME_ACCOUNTING ++ u64 prev_irq_time; ++#endif /* CONFIG_IRQ_TIME_ACCOUNTING */ ++#ifdef CONFIG_PARAVIRT ++ u64 prev_steal_time; ++#endif /* CONFIG_PARAVIRT */ ++#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING ++ u64 prev_steal_time_rq; ++#endif /* CONFIG_PARAVIRT_TIME_ACCOUNTING */ ++ ++ /* For genenal cpu load util */ ++ s32 load_history; ++ u64 load_block; ++ u64 load_stamp; ++ ++ /* calc_load related fields */ ++ unsigned long calc_load_update; ++ long calc_load_active; ++ ++ /* Ensure that all clocks are in the same cache line */ ++ u64 clock ____cacheline_aligned; ++ u64 clock_task; ++#ifdef CONFIG_SCHED_BMQ ++ u64 last_ts_switch; ++#endif ++ ++ unsigned int nr_running; ++ unsigned long nr_uninterruptible; ++ ++#ifdef CONFIG_SCHED_HRTICK ++#ifdef CONFIG_SMP ++ call_single_data_t hrtick_csd; ++#endif ++ struct hrtimer hrtick_timer; ++ ktime_t hrtick_time; ++#endif ++ ++#ifdef CONFIG_SCHEDSTATS ++ ++ /* latency stats */ ++ struct sched_info rq_sched_info; ++ unsigned long long rq_cpu_time; ++ /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ ++ ++ /* sys_sched_yield() stats */ ++ unsigned int yld_count; ++ ++ /* schedule() stats */ ++ unsigned int sched_switch; ++ unsigned int sched_count; ++ unsigned int sched_goidle; ++ ++ /* try_to_wake_up() stats */ ++ unsigned int ttwu_count; ++ unsigned int ttwu_local; ++#endif /* CONFIG_SCHEDSTATS */ ++ ++#ifdef CONFIG_CPU_IDLE ++ /* Must be inspected within a rcu lock section */ ++ struct cpuidle_state *idle_state; ++#endif ++ ++#ifdef CONFIG_NO_HZ_COMMON ++#ifdef CONFIG_SMP ++ call_single_data_t nohz_csd; ++#endif ++ atomic_t nohz_flags; ++#endif /* CONFIG_NO_HZ_COMMON */ ++ ++ /* Scratch cpumask to be temporarily used under rq_lock */ ++ cpumask_var_t scratch_mask; ++}; ++ ++extern unsigned long rq_load_util(struct rq *rq, unsigned long max); ++ ++extern unsigned long calc_load_update; ++extern atomic_long_t calc_load_tasks; ++ ++extern void calc_global_load_tick(struct rq *this_rq); ++extern long calc_load_fold_active(struct rq *this_rq, long adjust); ++ ++DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); ++#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) ++#define this_rq() this_cpu_ptr(&runqueues) ++#define task_rq(p) cpu_rq(task_cpu(p)) ++#define cpu_curr(cpu) (cpu_rq(cpu)->curr) ++#define raw_rq() raw_cpu_ptr(&runqueues) ++ ++#ifdef CONFIG_SMP ++#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) ++void register_sched_domain_sysctl(void); ++void unregister_sched_domain_sysctl(void); ++#else ++static inline void register_sched_domain_sysctl(void) ++{ ++} ++static inline void unregister_sched_domain_sysctl(void) ++{ ++} ++#endif ++ ++extern bool sched_smp_initialized; ++ ++enum { ++ ITSELF_LEVEL_SPACE_HOLDER, ++#ifdef CONFIG_SCHED_SMT ++ SMT_LEVEL_SPACE_HOLDER, ++#endif ++ COREGROUP_LEVEL_SPACE_HOLDER, ++ CORE_LEVEL_SPACE_HOLDER, ++ OTHER_LEVEL_SPACE_HOLDER, ++ NR_CPU_AFFINITY_LEVELS ++}; ++ ++DECLARE_PER_CPU_ALIGNED(cpumask_t [NR_CPU_AFFINITY_LEVELS], sched_cpu_topo_masks); ++ ++static inline int ++__best_mask_cpu(const cpumask_t *cpumask, const cpumask_t *mask) ++{ ++ int cpu; ++ ++ while ((cpu = cpumask_any_and(cpumask, mask)) >= nr_cpu_ids) ++ mask++; ++ ++ return cpu; ++} ++ ++static inline int best_mask_cpu(int cpu, const cpumask_t *mask) ++{ ++ return __best_mask_cpu(mask, per_cpu(sched_cpu_topo_masks, cpu)); ++} ++ ++extern void flush_smp_call_function_queue(void); ++ ++#else /* !CONFIG_SMP */ ++static inline void flush_smp_call_function_queue(void) { } ++#endif ++ ++#ifndef arch_scale_freq_tick ++static __always_inline ++void arch_scale_freq_tick(void) ++{ ++} ++#endif ++ ++#ifndef arch_scale_freq_capacity ++static __always_inline ++unsigned long arch_scale_freq_capacity(int cpu) ++{ ++ return SCHED_CAPACITY_SCALE; ++} ++#endif ++ ++static inline u64 __rq_clock_broken(struct rq *rq) ++{ ++ return READ_ONCE(rq->clock); ++} ++ ++static inline u64 rq_clock(struct rq *rq) ++{ ++ /* ++ * Relax lockdep_assert_held() checking as in VRQ, call to ++ * sched_info_xxxx() may not held rq->lock ++ * lockdep_assert_held(&rq->lock); ++ */ ++ return rq->clock; ++} ++ ++static inline u64 rq_clock_task(struct rq *rq) ++{ ++ /* ++ * Relax lockdep_assert_held() checking as in VRQ, call to ++ * sched_info_xxxx() may not held rq->lock ++ * lockdep_assert_held(&rq->lock); ++ */ ++ return rq->clock_task; ++} ++ ++/* ++ * {de,en}queue flags: ++ * ++ * DEQUEUE_SLEEP - task is no longer runnable ++ * ENQUEUE_WAKEUP - task just became runnable ++ * ++ */ ++ ++#define DEQUEUE_SLEEP 0x01 ++ ++#define ENQUEUE_WAKEUP 0x01 ++ ++ ++/* ++ * Below are scheduler API which using in other kernel code ++ * It use the dummy rq_flags ++ * ToDo : BMQ need to support these APIs for compatibility with mainline ++ * scheduler code. ++ */ ++struct rq_flags { ++ unsigned long flags; ++}; ++ ++struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) ++ __acquires(rq->lock); ++ ++struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) ++ __acquires(p->pi_lock) ++ __acquires(rq->lock); ++ ++static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf) ++ __releases(rq->lock) ++{ ++ raw_spin_unlock(&rq->lock); ++} ++ ++static inline void ++task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf) ++ __releases(rq->lock) ++ __releases(p->pi_lock) ++{ ++ raw_spin_unlock(&rq->lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); ++} ++ ++static inline void ++rq_lock(struct rq *rq, struct rq_flags *rf) ++ __acquires(rq->lock) ++{ ++ raw_spin_lock(&rq->lock); ++} ++ ++static inline void ++rq_unlock(struct rq *rq, struct rq_flags *rf) ++ __releases(rq->lock) ++{ ++ raw_spin_unlock(&rq->lock); ++} ++ ++static inline void ++rq_lock_irq(struct rq *rq, struct rq_flags *rf) ++ __acquires(rq->lock) ++{ ++ raw_spin_lock_irq(&rq->lock); ++} ++ ++static inline void ++rq_unlock_irq(struct rq *rq, struct rq_flags *rf) ++ __releases(rq->lock) ++{ ++ raw_spin_unlock_irq(&rq->lock); ++} ++ ++static inline struct rq * ++this_rq_lock_irq(struct rq_flags *rf) ++ __acquires(rq->lock) ++{ ++ struct rq *rq; ++ ++ local_irq_disable(); ++ rq = this_rq(); ++ raw_spin_lock(&rq->lock); ++ ++ return rq; ++} ++ ++static inline raw_spinlock_t *__rq_lockp(struct rq *rq) ++{ ++ return &rq->lock; ++} ++ ++static inline raw_spinlock_t *rq_lockp(struct rq *rq) ++{ ++ return __rq_lockp(rq); ++} ++ ++static inline void lockdep_assert_rq_held(struct rq *rq) ++{ ++ lockdep_assert_held(__rq_lockp(rq)); ++} ++ ++extern void raw_spin_rq_lock_nested(struct rq *rq, int subclass); ++extern void raw_spin_rq_unlock(struct rq *rq); ++ ++static inline void raw_spin_rq_lock(struct rq *rq) ++{ ++ raw_spin_rq_lock_nested(rq, 0); ++} ++ ++static inline void raw_spin_rq_lock_irq(struct rq *rq) ++{ ++ local_irq_disable(); ++ raw_spin_rq_lock(rq); ++} ++ ++static inline void raw_spin_rq_unlock_irq(struct rq *rq) ++{ ++ raw_spin_rq_unlock(rq); ++ local_irq_enable(); ++} ++ ++static inline int task_current(struct rq *rq, struct task_struct *p) ++{ ++ return rq->curr == p; ++} ++ ++static inline bool task_on_cpu(struct task_struct *p) ++{ ++ return p->on_cpu; ++} ++ ++extern int task_running_nice(struct task_struct *p); ++ ++extern struct static_key_false sched_schedstats; ++ ++#ifdef CONFIG_CPU_IDLE ++static inline void idle_set_state(struct rq *rq, ++ struct cpuidle_state *idle_state) ++{ ++ rq->idle_state = idle_state; ++} ++ ++static inline struct cpuidle_state *idle_get_state(struct rq *rq) ++{ ++ WARN_ON(!rcu_read_lock_held()); ++ return rq->idle_state; ++} ++#else ++static inline void idle_set_state(struct rq *rq, ++ struct cpuidle_state *idle_state) ++{ ++} ++ ++static inline struct cpuidle_state *idle_get_state(struct rq *rq) ++{ ++ return NULL; ++} ++#endif ++ ++static inline int cpu_of(const struct rq *rq) ++{ ++#ifdef CONFIG_SMP ++ return rq->cpu; ++#else ++ return 0; ++#endif ++} ++ ++#include "stats.h" ++ ++#ifdef CONFIG_NO_HZ_COMMON ++#define NOHZ_BALANCE_KICK_BIT 0 ++#define NOHZ_STATS_KICK_BIT 1 ++ ++#define NOHZ_BALANCE_KICK BIT(NOHZ_BALANCE_KICK_BIT) ++#define NOHZ_STATS_KICK BIT(NOHZ_STATS_KICK_BIT) ++ ++#define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK) ++ ++#define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) ++ ++/* TODO: needed? ++extern void nohz_balance_exit_idle(struct rq *rq); ++#else ++static inline void nohz_balance_exit_idle(struct rq *rq) { } ++*/ ++#endif ++ ++#ifdef CONFIG_IRQ_TIME_ACCOUNTING ++struct irqtime { ++ u64 total; ++ u64 tick_delta; ++ u64 irq_start_time; ++ struct u64_stats_sync sync; ++}; ++ ++DECLARE_PER_CPU(struct irqtime, cpu_irqtime); ++ ++/* ++ * Returns the irqtime minus the softirq time computed by ksoftirqd. ++ * Otherwise ksoftirqd's sum_exec_runtime is substracted its own runtime ++ * and never move forward. ++ */ ++static inline u64 irq_time_read(int cpu) ++{ ++ struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu); ++ unsigned int seq; ++ u64 total; ++ ++ do { ++ seq = __u64_stats_fetch_begin(&irqtime->sync); ++ total = irqtime->total; ++ } while (__u64_stats_fetch_retry(&irqtime->sync, seq)); ++ ++ return total; ++} ++#endif /* CONFIG_IRQ_TIME_ACCOUNTING */ ++ ++#ifdef CONFIG_CPU_FREQ ++DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); ++#endif /* CONFIG_CPU_FREQ */ ++ ++#ifdef CONFIG_NO_HZ_FULL ++extern int __init sched_tick_offload_init(void); ++#else ++static inline int sched_tick_offload_init(void) { return 0; } ++#endif ++ ++#ifdef arch_scale_freq_capacity ++#ifndef arch_scale_freq_invariant ++#define arch_scale_freq_invariant() (true) ++#endif ++#else /* arch_scale_freq_capacity */ ++#define arch_scale_freq_invariant() (false) ++#endif ++ ++extern void schedule_idle(void); ++ ++#define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT) ++ ++/* ++ * !! For sched_setattr_nocheck() (kernel) only !! ++ * ++ * This is actually gross. :( ++ * ++ * It is used to make schedutil kworker(s) higher priority than SCHED_DEADLINE ++ * tasks, but still be able to sleep. We need this on platforms that cannot ++ * atomically change clock frequency. Remove once fast switching will be ++ * available on such platforms. ++ * ++ * SUGOV stands for SchedUtil GOVernor. ++ */ ++#define SCHED_FLAG_SUGOV 0x10000000 ++ ++#ifdef CONFIG_MEMBARRIER ++/* ++ * The scheduler provides memory barriers required by membarrier between: ++ * - prior user-space memory accesses and store to rq->membarrier_state, ++ * - store to rq->membarrier_state and following user-space memory accesses. ++ * In the same way it provides those guarantees around store to rq->curr. ++ */ ++static inline void membarrier_switch_mm(struct rq *rq, ++ struct mm_struct *prev_mm, ++ struct mm_struct *next_mm) ++{ ++ int membarrier_state; ++ ++ if (prev_mm == next_mm) ++ return; ++ ++ membarrier_state = atomic_read(&next_mm->membarrier_state); ++ if (READ_ONCE(rq->membarrier_state) == membarrier_state) ++ return; ++ ++ WRITE_ONCE(rq->membarrier_state, membarrier_state); ++} ++#else ++static inline void membarrier_switch_mm(struct rq *rq, ++ struct mm_struct *prev_mm, ++ struct mm_struct *next_mm) ++{ ++} ++#endif ++ ++#ifdef CONFIG_NUMA ++extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu); ++#else ++static inline int sched_numa_find_closest(const struct cpumask *cpus, int cpu) ++{ ++ return nr_cpu_ids; ++} ++#endif ++ ++extern void swake_up_all_locked(struct swait_queue_head *q); ++extern void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait); ++ ++extern int try_to_wake_up(struct task_struct *tsk, unsigned int state, int wake_flags); ++ ++#ifdef CONFIG_PREEMPT_DYNAMIC ++extern int preempt_dynamic_mode; ++extern int sched_dynamic_mode(const char *str); ++extern void sched_dynamic_update(int mode); ++#endif ++ ++static inline void nohz_run_idle_balance(int cpu) { } ++ ++static inline ++unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, ++ struct task_struct *p) ++{ ++ return util; ++} ++ ++static inline bool uclamp_rq_is_capped(struct rq *rq) { return false; } ++ ++#ifdef CONFIG_SCHED_MM_CID ++ ++#define SCHED_MM_CID_PERIOD_NS (100ULL * 1000000) /* 100ms */ ++#define MM_CID_SCAN_DELAY 100 /* 100ms */ ++ ++extern raw_spinlock_t cid_lock; ++extern int use_cid_lock; ++ ++extern void sched_mm_cid_migrate_from(struct task_struct *t); ++extern void sched_mm_cid_migrate_to(struct rq *dst_rq, struct task_struct *t, int src_cpu); ++extern void task_tick_mm_cid(struct rq *rq, struct task_struct *curr); ++extern void init_sched_mm_cid(struct task_struct *t); ++ ++static inline void __mm_cid_put(struct mm_struct *mm, int cid) ++{ ++ if (cid < 0) ++ return; ++ cpumask_clear_cpu(cid, mm_cidmask(mm)); ++} ++ ++/* ++ * The per-mm/cpu cid can have the MM_CID_LAZY_PUT flag set or transition to ++ * the MM_CID_UNSET state without holding the rq lock, but the rq lock needs to ++ * be held to transition to other states. ++ * ++ * State transitions synchronized with cmpxchg or try_cmpxchg need to be ++ * consistent across cpus, which prevents use of this_cpu_cmpxchg. ++ */ ++static inline void mm_cid_put_lazy(struct task_struct *t) ++{ ++ struct mm_struct *mm = t->mm; ++ struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid; ++ int cid; ++ ++ lockdep_assert_irqs_disabled(); ++ cid = __this_cpu_read(pcpu_cid->cid); ++ if (!mm_cid_is_lazy_put(cid) || ++ !try_cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, &cid, MM_CID_UNSET)) ++ return; ++ __mm_cid_put(mm, mm_cid_clear_lazy_put(cid)); ++} ++ ++static inline int mm_cid_pcpu_unset(struct mm_struct *mm) ++{ ++ struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid; ++ int cid, res; ++ ++ lockdep_assert_irqs_disabled(); ++ cid = __this_cpu_read(pcpu_cid->cid); ++ for (;;) { ++ if (mm_cid_is_unset(cid)) ++ return MM_CID_UNSET; ++ /* ++ * Attempt transition from valid or lazy-put to unset. ++ */ ++ res = cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, cid, MM_CID_UNSET); ++ if (res == cid) ++ break; ++ cid = res; ++ } ++ return cid; ++} ++ ++static inline void mm_cid_put(struct mm_struct *mm) ++{ ++ int cid; ++ ++ lockdep_assert_irqs_disabled(); ++ cid = mm_cid_pcpu_unset(mm); ++ if (cid == MM_CID_UNSET) ++ return; ++ __mm_cid_put(mm, mm_cid_clear_lazy_put(cid)); ++} ++ ++static inline int __mm_cid_try_get(struct mm_struct *mm) ++{ ++ struct cpumask *cpumask; ++ int cid; ++ ++ cpumask = mm_cidmask(mm); ++ /* ++ * Retry finding first zero bit if the mask is temporarily ++ * filled. This only happens during concurrent remote-clear ++ * which owns a cid without holding a rq lock. ++ */ ++ for (;;) { ++ cid = cpumask_first_zero(cpumask); ++ if (cid < nr_cpu_ids) ++ break; ++ cpu_relax(); ++ } ++ if (cpumask_test_and_set_cpu(cid, cpumask)) ++ return -1; ++ return cid; ++} ++ ++/* ++ * Save a snapshot of the current runqueue time of this cpu ++ * with the per-cpu cid value, allowing to estimate how recently it was used. ++ */ ++static inline void mm_cid_snapshot_time(struct rq *rq, struct mm_struct *mm) ++{ ++ struct mm_cid *pcpu_cid = per_cpu_ptr(mm->pcpu_cid, cpu_of(rq)); ++ ++ lockdep_assert_rq_held(rq); ++ WRITE_ONCE(pcpu_cid->time, rq->clock); ++} ++ ++static inline int __mm_cid_get(struct rq *rq, struct mm_struct *mm) ++{ ++ int cid; ++ ++ /* ++ * All allocations (even those using the cid_lock) are lock-free. If ++ * use_cid_lock is set, hold the cid_lock to perform cid allocation to ++ * guarantee forward progress. ++ */ ++ if (!READ_ONCE(use_cid_lock)) { ++ cid = __mm_cid_try_get(mm); ++ if (cid >= 0) ++ goto end; ++ raw_spin_lock(&cid_lock); ++ } else { ++ raw_spin_lock(&cid_lock); ++ cid = __mm_cid_try_get(mm); ++ if (cid >= 0) ++ goto unlock; ++ } ++ ++ /* ++ * cid concurrently allocated. Retry while forcing following ++ * allocations to use the cid_lock to ensure forward progress. ++ */ ++ WRITE_ONCE(use_cid_lock, 1); ++ /* ++ * Set use_cid_lock before allocation. Only care about program order ++ * because this is only required for forward progress. ++ */ ++ barrier(); ++ /* ++ * Retry until it succeeds. It is guaranteed to eventually succeed once ++ * all newcoming allocations observe the use_cid_lock flag set. ++ */ ++ do { ++ cid = __mm_cid_try_get(mm); ++ cpu_relax(); ++ } while (cid < 0); ++ /* ++ * Allocate before clearing use_cid_lock. Only care about ++ * program order because this is for forward progress. ++ */ ++ barrier(); ++ WRITE_ONCE(use_cid_lock, 0); ++unlock: ++ raw_spin_unlock(&cid_lock); ++end: ++ mm_cid_snapshot_time(rq, mm); ++ return cid; ++} ++ ++static inline int mm_cid_get(struct rq *rq, struct mm_struct *mm) ++{ ++ struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid; ++ struct cpumask *cpumask; ++ int cid; ++ ++ lockdep_assert_rq_held(rq); ++ cpumask = mm_cidmask(mm); ++ cid = __this_cpu_read(pcpu_cid->cid); ++ if (mm_cid_is_valid(cid)) { ++ mm_cid_snapshot_time(rq, mm); ++ return cid; ++ } ++ if (mm_cid_is_lazy_put(cid)) { ++ if (try_cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, &cid, MM_CID_UNSET)) ++ __mm_cid_put(mm, mm_cid_clear_lazy_put(cid)); ++ } ++ cid = __mm_cid_get(rq, mm); ++ __this_cpu_write(pcpu_cid->cid, cid); ++ return cid; ++} ++ ++static inline void switch_mm_cid(struct rq *rq, ++ struct task_struct *prev, ++ struct task_struct *next) ++{ ++ /* ++ * Provide a memory barrier between rq->curr store and load of ++ * {prev,next}->mm->pcpu_cid[cpu] on rq->curr->mm transition. ++ * ++ * Should be adapted if context_switch() is modified. ++ */ ++ if (!next->mm) { // to kernel ++ /* ++ * user -> kernel transition does not guarantee a barrier, but ++ * we can use the fact that it performs an atomic operation in ++ * mmgrab(). ++ */ ++ if (prev->mm) // from user ++ smp_mb__after_mmgrab(); ++ /* ++ * kernel -> kernel transition does not change rq->curr->mm ++ * state. It stays NULL. ++ */ ++ } else { // to user ++ /* ++ * kernel -> user transition does not provide a barrier ++ * between rq->curr store and load of {prev,next}->mm->pcpu_cid[cpu]. ++ * Provide it here. ++ */ ++ if (!prev->mm) // from kernel ++ smp_mb(); ++ /* ++ * user -> user transition guarantees a memory barrier through ++ * switch_mm() when current->mm changes. If current->mm is ++ * unchanged, no barrier is needed. ++ */ ++ } ++ if (prev->mm_cid_active) { ++ mm_cid_snapshot_time(rq, prev->mm); ++ mm_cid_put_lazy(prev); ++ prev->mm_cid = -1; ++ } ++ if (next->mm_cid_active) ++ next->last_mm_cid = next->mm_cid = mm_cid_get(rq, next->mm); ++} ++ ++#else ++static inline void switch_mm_cid(struct rq *rq, struct task_struct *prev, struct task_struct *next) { } ++static inline void sched_mm_cid_migrate_from(struct task_struct *t) { } ++static inline void sched_mm_cid_migrate_to(struct rq *dst_rq, struct task_struct *t, int src_cpu) { } ++static inline void task_tick_mm_cid(struct rq *rq, struct task_struct *curr) { } ++static inline void init_sched_mm_cid(struct task_struct *t) { } ++#endif ++ ++#endif /* ALT_SCHED_H */ +diff --git a/kernel/sched/bmq.h b/kernel/sched/bmq.h +new file mode 100644 +index 000000000000..d8f6381c27a9 +--- /dev/null ++++ b/kernel/sched/bmq.h +@@ -0,0 +1,101 @@ ++#define ALT_SCHED_NAME "BMQ" ++ ++/* ++ * BMQ only routines ++ */ ++#define rq_switch_time(rq) ((rq)->clock - (rq)->last_ts_switch) ++#define boost_threshold(p) (sched_timeslice_ns >> ((14 - (p)->boost_prio) / 2)) ++ ++static inline void boost_task(struct task_struct *p) ++{ ++ int limit; ++ ++ switch (p->policy) { ++ case SCHED_NORMAL: ++ limit = -MAX_PRIORITY_ADJ; ++ break; ++ case SCHED_BATCH: ++ case SCHED_IDLE: ++ limit = 0; ++ break; ++ default: ++ return; ++ } ++ ++ if (p->boost_prio > limit) ++ p->boost_prio--; ++} ++ ++static inline void deboost_task(struct task_struct *p) ++{ ++ if (p->boost_prio < MAX_PRIORITY_ADJ) ++ p->boost_prio++; ++} ++ ++/* ++ * Common interfaces ++ */ ++static inline void sched_timeslice_imp(const int timeslice_ms) {} ++ ++static inline int ++task_sched_prio_normal(const struct task_struct *p, const struct rq *rq) ++{ ++ return p->prio + p->boost_prio - MAX_RT_PRIO; ++} ++ ++static inline int task_sched_prio(const struct task_struct *p) ++{ ++ return (p->prio < MAX_RT_PRIO)? (p->prio >> 2) : ++ MIN_SCHED_NORMAL_PRIO + (p->prio + p->boost_prio - MAX_RT_PRIO) / 2; ++} ++ ++static inline int ++task_sched_prio_idx(const struct task_struct *p, const struct rq *rq) ++{ ++ return task_sched_prio(p); ++} ++ ++static inline int sched_prio2idx(int prio, struct rq *rq) ++{ ++ return prio; ++} ++ ++static inline int sched_idx2prio(int idx, struct rq *rq) ++{ ++ return idx; ++} ++ ++inline int task_running_nice(struct task_struct *p) ++{ ++ return (p->prio + p->boost_prio > DEFAULT_PRIO + MAX_PRIORITY_ADJ); ++} ++ ++static inline void sched_update_rq_clock(struct rq *rq) {} ++static inline void sched_task_renew(struct task_struct *p, const struct rq *rq) {} ++static inline void sched_task_sanity_check(struct task_struct *p, struct rq *rq) {} ++ ++static void sched_task_fork(struct task_struct *p, struct rq *rq) ++{ ++ p->boost_prio = MAX_PRIORITY_ADJ; ++} ++ ++static inline void do_sched_yield_type_1(struct task_struct *p, struct rq *rq) ++{ ++ p->boost_prio = MAX_PRIORITY_ADJ; ++} ++ ++static inline void sched_task_ttwu(struct task_struct *p) ++{ ++ if(this_rq()->clock_task - p->last_ran > sched_timeslice_ns) ++ boost_task(p); ++} ++ ++static inline void sched_task_deactivate(struct task_struct *p, struct rq *rq) ++{ ++ u64 switch_ns = rq_switch_time(rq); ++ ++ if (switch_ns < boost_threshold(p)) ++ boost_task(p); ++ else if (switch_ns > sched_timeslice_ns) ++ deboost_task(p); ++} +diff --git a/kernel/sched/build_policy.c b/kernel/sched/build_policy.c +index d9dc9ab3773f..71a25540d65e 100644 +--- a/kernel/sched/build_policy.c ++++ b/kernel/sched/build_policy.c +@@ -42,13 +42,19 @@ + + #include "idle.c" + ++#ifndef CONFIG_SCHED_ALT + #include "rt.c" ++#endif + + #ifdef CONFIG_SMP ++#ifndef CONFIG_SCHED_ALT + # include "cpudeadline.c" ++#endif + # include "pelt.c" + #endif + + #include "cputime.c" +-#include "deadline.c" + ++#ifndef CONFIG_SCHED_ALT ++#include "deadline.c" ++#endif +diff --git a/kernel/sched/build_utility.c b/kernel/sched/build_utility.c +index 80a3df49ab47..bc17d5a6fc41 100644 +--- a/kernel/sched/build_utility.c ++++ b/kernel/sched/build_utility.c +@@ -84,7 +84,9 @@ + + #ifdef CONFIG_SMP + # include "cpupri.c" ++#ifndef CONFIG_SCHED_ALT + # include "stop_task.c" ++#endif + # include "topology.c" + #endif + +diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c +index 5888176354e2..6ab2534714f6 100644 +--- a/kernel/sched/cpufreq_schedutil.c ++++ b/kernel/sched/cpufreq_schedutil.c +@@ -155,12 +155,18 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy, + + static void sugov_get_util(struct sugov_cpu *sg_cpu) + { +- unsigned long util = cpu_util_cfs_boost(sg_cpu->cpu); + struct rq *rq = cpu_rq(sg_cpu->cpu); + ++#ifndef CONFIG_SCHED_ALT ++ unsigned long util = cpu_util_cfs_boost(sg_cpu->cpu); ++ + sg_cpu->bw_dl = cpu_bw_dl(rq); + sg_cpu->util = effective_cpu_util(sg_cpu->cpu, util, + FREQUENCY_UTIL, NULL); ++#else ++ sg_cpu->bw_dl = 0; ++ sg_cpu->util = rq_load_util(rq, arch_scale_cpu_capacity(sg_cpu->cpu)); ++#endif /* CONFIG_SCHED_ALT */ + } + + /** +@@ -306,8 +312,10 @@ static inline bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) { return false; } + */ + static inline void ignore_dl_rate_limit(struct sugov_cpu *sg_cpu) + { ++#ifndef CONFIG_SCHED_ALT + if (cpu_bw_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->bw_dl) + sg_cpu->sg_policy->limits_changed = true; ++#endif + } + + static inline bool sugov_update_single_common(struct sugov_cpu *sg_cpu, +@@ -636,6 +644,7 @@ static int sugov_kthread_create(struct sugov_policy *sg_policy) + } + + ret = sched_setattr_nocheck(thread, &attr); ++ + if (ret) { + kthread_stop(thread); + pr_warn("%s: failed to set SCHED_DEADLINE\n", __func__); +diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c +index af7952f12e6c..6461cbbb734d 100644 +--- a/kernel/sched/cputime.c ++++ b/kernel/sched/cputime.c +@@ -126,7 +126,7 @@ void account_user_time(struct task_struct *p, u64 cputime) + p->utime += cputime; + account_group_user_time(p, cputime); + +- index = (task_nice(p) > 0) ? CPUTIME_NICE : CPUTIME_USER; ++ index = task_running_nice(p) ? CPUTIME_NICE : CPUTIME_USER; + + /* Add user time to cpustat. */ + task_group_account_field(p, index, cputime); +@@ -150,7 +150,7 @@ void account_guest_time(struct task_struct *p, u64 cputime) + p->gtime += cputime; + + /* Add guest time to cpustat. */ +- if (task_nice(p) > 0) { ++ if (task_running_nice(p)) { + task_group_account_field(p, CPUTIME_NICE, cputime); + cpustat[CPUTIME_GUEST_NICE] += cputime; + } else { +@@ -288,7 +288,7 @@ static inline u64 account_other_time(u64 max) + #ifdef CONFIG_64BIT + static inline u64 read_sum_exec_runtime(struct task_struct *t) + { +- return t->se.sum_exec_runtime; ++ return tsk_seruntime(t); + } + #else + static u64 read_sum_exec_runtime(struct task_struct *t) +@@ -298,7 +298,7 @@ static u64 read_sum_exec_runtime(struct task_struct *t) + struct rq *rq; + + rq = task_rq_lock(t, &rf); +- ns = t->se.sum_exec_runtime; ++ ns = tsk_seruntime(t); + task_rq_unlock(rq, t, &rf); + + return ns; +@@ -630,7 +630,7 @@ void cputime_adjust(struct task_cputime *curr, struct prev_cputime *prev, + void task_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st) + { + struct task_cputime cputime = { +- .sum_exec_runtime = p->se.sum_exec_runtime, ++ .sum_exec_runtime = tsk_seruntime(p), + }; + + if (task_cputime(p, &cputime.utime, &cputime.stime)) +diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c +index 4580a450700e..21c15b4488fe 100644 +--- a/kernel/sched/debug.c ++++ b/kernel/sched/debug.c +@@ -7,6 +7,7 @@ + * Copyright(C) 2007, Red Hat, Inc., Ingo Molnar + */ + ++#ifndef CONFIG_SCHED_ALT + /* + * This allows printing both to /sys/kernel/debug/sched/debug and + * to the console +@@ -215,6 +216,7 @@ static const struct file_operations sched_scaling_fops = { + }; + + #endif /* SMP */ ++#endif /* !CONFIG_SCHED_ALT */ + + #ifdef CONFIG_PREEMPT_DYNAMIC + +@@ -278,6 +280,7 @@ static const struct file_operations sched_dynamic_fops = { + + #endif /* CONFIG_PREEMPT_DYNAMIC */ + ++#ifndef CONFIG_SCHED_ALT + __read_mostly bool sched_debug_verbose; + + #ifdef CONFIG_SMP +@@ -332,6 +335,7 @@ static const struct file_operations sched_debug_fops = { + .llseek = seq_lseek, + .release = seq_release, + }; ++#endif /* !CONFIG_SCHED_ALT */ + + static struct dentry *debugfs_sched; + +@@ -341,12 +345,16 @@ static __init int sched_init_debug(void) + + debugfs_sched = debugfs_create_dir("sched", NULL); + ++#ifndef CONFIG_SCHED_ALT + debugfs_create_file("features", 0644, debugfs_sched, NULL, &sched_feat_fops); + debugfs_create_file_unsafe("verbose", 0644, debugfs_sched, &sched_debug_verbose, &sched_verbose_fops); ++ debugfs_create_bool("verbose", 0644, debugfs_sched, &sched_debug_verbose); ++#endif /* !CONFIG_SCHED_ALT */ + #ifdef CONFIG_PREEMPT_DYNAMIC + debugfs_create_file("preempt", 0644, debugfs_sched, NULL, &sched_dynamic_fops); + #endif + ++#ifndef CONFIG_SCHED_ALT + debugfs_create_u32("base_slice_ns", 0644, debugfs_sched, &sysctl_sched_base_slice); + + debugfs_create_u32("latency_warn_ms", 0644, debugfs_sched, &sysctl_resched_latency_warn_ms); +@@ -373,11 +381,13 @@ static __init int sched_init_debug(void) + #endif + + debugfs_create_file("debug", 0444, debugfs_sched, NULL, &sched_debug_fops); ++#endif /* !CONFIG_SCHED_ALT */ + + return 0; + } + late_initcall(sched_init_debug); + ++#ifndef CONFIG_SCHED_ALT + #ifdef CONFIG_SMP + + static cpumask_var_t sd_sysctl_cpus; +@@ -1106,6 +1116,7 @@ void proc_sched_set_task(struct task_struct *p) + memset(&p->stats, 0, sizeof(p->stats)); + #endif + } ++#endif /* !CONFIG_SCHED_ALT */ + + void resched_latency_warn(int cpu, u64 latency) + { +diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c +index 565f8374ddbb..67d51e05a8ac 100644 +--- a/kernel/sched/idle.c ++++ b/kernel/sched/idle.c +@@ -380,6 +380,7 @@ void cpu_startup_entry(enum cpuhp_state state) + do_idle(); + } + ++#ifndef CONFIG_SCHED_ALT + /* + * idle-task scheduling class. + */ +@@ -501,3 +502,4 @@ DEFINE_SCHED_CLASS(idle) = { + .switched_to = switched_to_idle, + .update_curr = update_curr_idle, + }; ++#endif +diff --git a/kernel/sched/pds.h b/kernel/sched/pds.h +new file mode 100644 +index 000000000000..b20226ed47cc +--- /dev/null ++++ b/kernel/sched/pds.h +@@ -0,0 +1,142 @@ ++#define ALT_SCHED_NAME "PDS" ++ ++static const u64 RT_MASK = ((1ULL << MIN_SCHED_NORMAL_PRIO) - 1); ++ ++#define SCHED_NORMAL_PRIO_NUM (32) ++#define SCHED_EDGE_DELTA (SCHED_NORMAL_PRIO_NUM - NICE_WIDTH / 2) ++ ++/* PDS assume NORMAL_PRIO_NUM is power of 2 */ ++#define SCHED_NORMAL_PRIO_MOD(x) ((x) & (SCHED_NORMAL_PRIO_NUM - 1)) ++ ++/* default time slice 4ms -> shift 22, 2 time slice slots -> shift 23 */ ++static __read_mostly int sched_timeslice_shift = 23; ++ ++/* ++ * Common interfaces ++ */ ++static inline void sched_timeslice_imp(const int timeslice_ms) ++{ ++ if (2 == timeslice_ms) ++ sched_timeslice_shift = 22; ++} ++ ++static inline int ++task_sched_prio_normal(const struct task_struct *p, const struct rq *rq) ++{ ++ s64 delta = p->deadline - rq->time_edge + SCHED_EDGE_DELTA; ++ ++#ifdef ALT_SCHED_DEBUG ++ if (WARN_ONCE(delta > NORMAL_PRIO_NUM - 1, ++ "pds: task_sched_prio_normal() delta %lld\n", delta)) ++ return SCHED_NORMAL_PRIO_NUM - 1; ++#endif ++ ++ return max(0LL, delta); ++} ++ ++static inline int task_sched_prio(const struct task_struct *p) ++{ ++ return (p->prio < MIN_NORMAL_PRIO) ? (p->prio >> 2) : ++ MIN_SCHED_NORMAL_PRIO + task_sched_prio_normal(p, task_rq(p)); ++} ++ ++static inline int ++task_sched_prio_idx(const struct task_struct *p, const struct rq *rq) ++{ ++ u64 idx; ++ ++ if (p->prio < MIN_NORMAL_PRIO) ++ return p->prio >> 2; ++ ++ idx = max(p->deadline + SCHED_EDGE_DELTA, rq->time_edge); ++ /*printk(KERN_INFO "sched: task_sched_prio_idx edge:%llu, deadline=%llu idx=%llu\n", rq->time_edge, p->deadline, idx);*/ ++ return MIN_SCHED_NORMAL_PRIO + SCHED_NORMAL_PRIO_MOD(idx); ++} ++ ++static inline int sched_prio2idx(int sched_prio, struct rq *rq) ++{ ++ return (IDLE_TASK_SCHED_PRIO == sched_prio || sched_prio < MIN_SCHED_NORMAL_PRIO) ? ++ sched_prio : ++ MIN_SCHED_NORMAL_PRIO + SCHED_NORMAL_PRIO_MOD(sched_prio + rq->time_edge); ++} ++ ++static inline int sched_idx2prio(int sched_idx, struct rq *rq) ++{ ++ return (sched_idx < MIN_SCHED_NORMAL_PRIO) ? ++ sched_idx : ++ MIN_SCHED_NORMAL_PRIO + SCHED_NORMAL_PRIO_MOD(sched_idx - rq->time_edge); ++} ++ ++int task_running_nice(struct task_struct *p) ++{ ++ return (p->prio > DEFAULT_PRIO); ++} ++ ++static inline void sched_update_rq_clock(struct rq *rq) ++{ ++ struct list_head head; ++ u64 old = rq->time_edge; ++ u64 now = rq->clock >> sched_timeslice_shift; ++ u64 prio, delta; ++ DECLARE_BITMAP(normal, SCHED_QUEUE_BITS); ++ ++ if (now == old) ++ return; ++ ++ rq->time_edge = now; ++ delta = min_t(u64, SCHED_NORMAL_PRIO_NUM, now - old); ++ INIT_LIST_HEAD(&head); ++ ++ prio = MIN_SCHED_NORMAL_PRIO; ++ for_each_set_bit_from(prio, rq->queue.bitmap, MIN_SCHED_NORMAL_PRIO + delta) ++ list_splice_tail_init(rq->queue.heads + MIN_SCHED_NORMAL_PRIO + ++ SCHED_NORMAL_PRIO_MOD(prio + old), &head); ++ ++ bitmap_shift_right(normal, rq->queue.bitmap, delta, SCHED_QUEUE_BITS); ++ if (!list_empty(&head)) { ++ struct task_struct *p; ++ u64 idx = MIN_SCHED_NORMAL_PRIO + SCHED_NORMAL_PRIO_MOD(now); ++ ++ list_for_each_entry(p, &head, sq_node) ++ p->sq_idx = idx; ++ ++ list_splice(&head, rq->queue.heads + idx); ++ set_bit(MIN_SCHED_NORMAL_PRIO, normal); ++ } ++ bitmap_replace(rq->queue.bitmap, normal, rq->queue.bitmap, ++ (const unsigned long *)&RT_MASK, SCHED_QUEUE_BITS); ++ ++ if (rq->prio < MIN_SCHED_NORMAL_PRIO || IDLE_TASK_SCHED_PRIO == rq->prio) ++ return; ++ ++ rq->prio = (rq->prio < MIN_SCHED_NORMAL_PRIO + delta) ? ++ MIN_SCHED_NORMAL_PRIO : rq->prio - delta; ++} ++ ++static inline void sched_task_renew(struct task_struct *p, const struct rq *rq) ++{ ++ if (p->prio >= MIN_NORMAL_PRIO) ++ p->deadline = rq->time_edge + (p->static_prio - (MAX_PRIO - NICE_WIDTH)) / 2; ++} ++ ++static inline void sched_task_sanity_check(struct task_struct *p, struct rq *rq) ++{ ++ u64 max_dl = rq->time_edge + NICE_WIDTH / 2 - 1; ++ if (unlikely(p->deadline > max_dl)) ++ p->deadline = max_dl; ++} ++ ++static void sched_task_fork(struct task_struct *p, struct rq *rq) ++{ ++ sched_task_renew(p, rq); ++} ++ ++static inline void time_slice_expired(struct task_struct *p, struct rq *rq); ++ ++static inline void do_sched_yield_type_1(struct task_struct *p, struct rq *rq) ++{ ++ time_slice_expired(p, rq); ++} ++ ++static inline void sched_task_ttwu(struct task_struct *p) {} ++static inline void sched_task_deactivate(struct task_struct *p, struct rq *rq) {} +diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c +index 63b6cf898220..9ca10ece4d3a 100644 +--- a/kernel/sched/pelt.c ++++ b/kernel/sched/pelt.c +@@ -266,6 +266,7 @@ ___update_load_avg(struct sched_avg *sa, unsigned long load) + WRITE_ONCE(sa->util_avg, sa->util_sum / divider); + } + ++#ifndef CONFIG_SCHED_ALT + /* + * sched_entity: + * +@@ -383,8 +384,9 @@ int update_dl_rq_load_avg(u64 now, struct rq *rq, int running) + + return 0; + } ++#endif + +-#ifdef CONFIG_SCHED_THERMAL_PRESSURE ++#if defined(CONFIG_SCHED_THERMAL_PRESSURE) && !defined(CONFIG_SCHED_ALT) + /* + * thermal: + * +diff --git a/kernel/sched/pelt.h b/kernel/sched/pelt.h +index 3a0e0dc28721..e8a7d84aa5a5 100644 +--- a/kernel/sched/pelt.h ++++ b/kernel/sched/pelt.h +@@ -1,13 +1,15 @@ + #ifdef CONFIG_SMP + #include "sched-pelt.h" + ++#ifndef CONFIG_SCHED_ALT + int __update_load_avg_blocked_se(u64 now, struct sched_entity *se); + int __update_load_avg_se(u64 now, struct cfs_rq *cfs_rq, struct sched_entity *se); + int __update_load_avg_cfs_rq(u64 now, struct cfs_rq *cfs_rq); + int update_rt_rq_load_avg(u64 now, struct rq *rq, int running); + int update_dl_rq_load_avg(u64 now, struct rq *rq, int running); ++#endif + +-#ifdef CONFIG_SCHED_THERMAL_PRESSURE ++#if defined(CONFIG_SCHED_THERMAL_PRESSURE) && !defined(CONFIG_SCHED_ALT) + int update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity); + + static inline u64 thermal_load_avg(struct rq *rq) +@@ -44,6 +46,7 @@ static inline u32 get_pelt_divider(struct sched_avg *avg) + return PELT_MIN_DIVIDER + avg->period_contrib; + } + ++#ifndef CONFIG_SCHED_ALT + static inline void cfs_se_util_change(struct sched_avg *avg) + { + unsigned int enqueued; +@@ -180,9 +183,11 @@ static inline u64 cfs_rq_clock_pelt(struct cfs_rq *cfs_rq) + return rq_clock_pelt(rq_of(cfs_rq)); + } + #endif ++#endif /* CONFIG_SCHED_ALT */ + + #else + ++#ifndef CONFIG_SCHED_ALT + static inline int + update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq) + { +@@ -200,6 +205,7 @@ update_dl_rq_load_avg(u64 now, struct rq *rq, int running) + { + return 0; + } ++#endif + + static inline int + update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity) +diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h +index 2e5a95486a42..0c86131a2a64 100644 +--- a/kernel/sched/sched.h ++++ b/kernel/sched/sched.h +@@ -5,6 +5,10 @@ + #ifndef _KERNEL_SCHED_SCHED_H + #define _KERNEL_SCHED_SCHED_H + ++#ifdef CONFIG_SCHED_ALT ++#include "alt_sched.h" ++#else ++ + #include <linux/sched/affinity.h> + #include <linux/sched/autogroup.h> + #include <linux/sched/cpufreq.h> +@@ -3509,4 +3513,9 @@ static inline void init_sched_mm_cid(struct task_struct *t) { } + extern u64 avg_vruntime(struct cfs_rq *cfs_rq); + extern int entity_eligible(struct cfs_rq *cfs_rq, struct sched_entity *se); + ++static inline int task_running_nice(struct task_struct *p) ++{ ++ return (task_nice(p) > 0); ++} ++#endif /* !CONFIG_SCHED_ALT */ + #endif /* _KERNEL_SCHED_SCHED_H */ +diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c +index 857f837f52cb..5486c63e4790 100644 +--- a/kernel/sched/stats.c ++++ b/kernel/sched/stats.c +@@ -125,8 +125,10 @@ static int show_schedstat(struct seq_file *seq, void *v) + } else { + struct rq *rq; + #ifdef CONFIG_SMP ++#ifndef CONFIG_SCHED_ALT + struct sched_domain *sd; + int dcount = 0; ++#endif + #endif + cpu = (unsigned long)(v - 2); + rq = cpu_rq(cpu); +@@ -143,6 +145,7 @@ static int show_schedstat(struct seq_file *seq, void *v) + seq_printf(seq, "\n"); + + #ifdef CONFIG_SMP ++#ifndef CONFIG_SCHED_ALT + /* domain-specific stats */ + rcu_read_lock(); + for_each_domain(cpu, sd) { +@@ -171,6 +174,7 @@ static int show_schedstat(struct seq_file *seq, void *v) + sd->ttwu_move_balance); + } + rcu_read_unlock(); ++#endif + #endif + } + return 0; +diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h +index 38f3698f5e5b..b9d597394316 100644 +--- a/kernel/sched/stats.h ++++ b/kernel/sched/stats.h +@@ -89,6 +89,7 @@ static inline void rq_sched_info_depart (struct rq *rq, unsigned long long delt + + #endif /* CONFIG_SCHEDSTATS */ + ++#ifndef CONFIG_SCHED_ALT + #ifdef CONFIG_FAIR_GROUP_SCHED + struct sched_entity_stats { + struct sched_entity se; +@@ -105,6 +106,7 @@ __schedstats_from_se(struct sched_entity *se) + #endif + return &task_of(se)->stats; + } ++#endif /* CONFIG_SCHED_ALT */ + + #ifdef CONFIG_PSI + void psi_task_change(struct task_struct *task, int clear, int set); +diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c +index 10d1391e7416..120933a5b206 100644 +--- a/kernel/sched/topology.c ++++ b/kernel/sched/topology.c +@@ -3,6 +3,7 @@ + * Scheduler topology setup/handling methods + */ + ++#ifndef CONFIG_SCHED_ALT + #include <linux/bsearch.h> + + DEFINE_MUTEX(sched_domains_mutex); +@@ -1445,8 +1446,10 @@ static void asym_cpu_capacity_scan(void) + */ + + static int default_relax_domain_level = -1; ++#endif /* CONFIG_SCHED_ALT */ + int sched_domain_level_max; + ++#ifndef CONFIG_SCHED_ALT + static int __init setup_relax_domain_level(char *str) + { + if (kstrtoint(str, 0, &default_relax_domain_level)) +@@ -1680,6 +1683,7 @@ sd_init(struct sched_domain_topology_level *tl, + + return sd; + } ++#endif /* CONFIG_SCHED_ALT */ + + /* + * Topology list, bottom-up. +@@ -1716,6 +1720,7 @@ void __init set_sched_topology(struct sched_domain_topology_level *tl) + sched_domain_topology_saved = NULL; + } + ++#ifndef CONFIG_SCHED_ALT + #ifdef CONFIG_NUMA + + static const struct cpumask *sd_numa_mask(int cpu) +@@ -2793,3 +2798,20 @@ void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], + partition_sched_domains_locked(ndoms_new, doms_new, dattr_new); + mutex_unlock(&sched_domains_mutex); + } ++#else /* CONFIG_SCHED_ALT */ ++void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], ++ struct sched_domain_attr *dattr_new) ++{} ++ ++#ifdef CONFIG_NUMA ++int sched_numa_find_closest(const struct cpumask *cpus, int cpu) ++{ ++ return best_mask_cpu(cpu, cpus); ++} ++ ++int sched_numa_find_nth_cpu(const struct cpumask *cpus, int cpu, int node) ++{ ++ return cpumask_nth(cpu, cpus); ++} ++#endif /* CONFIG_NUMA */ ++#endif +diff --git a/kernel/sysctl.c b/kernel/sysctl.c +index 157f7ce2942d..63083a9a2935 100644 +--- a/kernel/sysctl.c ++++ b/kernel/sysctl.c +@@ -92,6 +92,10 @@ EXPORT_SYMBOL_GPL(sysctl_long_vals); + + /* Constants used for minimum and maximum */ + ++#ifdef CONFIG_SCHED_ALT ++extern int sched_yield_type; ++#endif ++ + #ifdef CONFIG_PERF_EVENTS + static const int six_hundred_forty_kb = 640 * 1024; + #endif +@@ -1912,6 +1916,17 @@ static struct ctl_table kern_table[] = { + .proc_handler = proc_dointvec, + }, + #endif ++#ifdef CONFIG_SCHED_ALT ++ { ++ .procname = "yield_type", ++ .data = &sched_yield_type, ++ .maxlen = sizeof (int), ++ .mode = 0644, ++ .proc_handler = &proc_dointvec_minmax, ++ .extra1 = SYSCTL_ZERO, ++ .extra2 = SYSCTL_TWO, ++ }, ++#endif + #if defined(CONFIG_S390) && defined(CONFIG_SMP) + { + .procname = "spin_retry", +diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c +index 760793998cdd..3198ed8ab40a 100644 +--- a/kernel/time/hrtimer.c ++++ b/kernel/time/hrtimer.c +@@ -2091,8 +2091,10 @@ long hrtimer_nanosleep(ktime_t rqtp, const enum hrtimer_mode mode, + int ret = 0; + u64 slack; + ++#ifndef CONFIG_SCHED_ALT + slack = current->timer_slack_ns; +- if (rt_task(current)) ++ if (dl_task(current) || rt_task(current)) ++#endif + slack = 0; + + hrtimer_init_sleeper_on_stack(&t, clockid, mode); +diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c +index e9c6f9d0e42c..43ee0a94abdd 100644 +--- a/kernel/time/posix-cpu-timers.c ++++ b/kernel/time/posix-cpu-timers.c +@@ -223,7 +223,7 @@ static void task_sample_cputime(struct task_struct *p, u64 *samples) + u64 stime, utime; + + task_cputime(p, &utime, &stime); +- store_samples(samples, stime, utime, p->se.sum_exec_runtime); ++ store_samples(samples, stime, utime, tsk_seruntime(p)); + } + + static void proc_sample_cputime_atomic(struct task_cputime_atomic *at, +@@ -867,6 +867,7 @@ static void collect_posix_cputimers(struct posix_cputimers *pct, u64 *samples, + } + } + ++#ifndef CONFIG_SCHED_ALT + static inline void check_dl_overrun(struct task_struct *tsk) + { + if (tsk->dl.dl_overrun) { +@@ -874,6 +875,7 @@ static inline void check_dl_overrun(struct task_struct *tsk) + send_signal_locked(SIGXCPU, SEND_SIG_PRIV, tsk, PIDTYPE_TGID); + } + } ++#endif + + static bool check_rlimit(u64 time, u64 limit, int signo, bool rt, bool hard) + { +@@ -901,8 +903,10 @@ static void check_thread_timers(struct task_struct *tsk, + u64 samples[CPUCLOCK_MAX]; + unsigned long soft; + ++#ifndef CONFIG_SCHED_ALT + if (dl_task(tsk)) + check_dl_overrun(tsk); ++#endif + + if (expiry_cache_is_inactive(pct)) + return; +@@ -916,7 +920,7 @@ static void check_thread_timers(struct task_struct *tsk, + soft = task_rlimit(tsk, RLIMIT_RTTIME); + if (soft != RLIM_INFINITY) { + /* Task RT timeout is accounted in jiffies. RTTIME is usec */ +- unsigned long rttime = tsk->rt.timeout * (USEC_PER_SEC / HZ); ++ unsigned long rttime = tsk_rttimeout(tsk) * (USEC_PER_SEC / HZ); + unsigned long hard = task_rlimit_max(tsk, RLIMIT_RTTIME); + + /* At the hard limit, send SIGKILL. No further action. */ +@@ -1152,8 +1156,10 @@ static inline bool fastpath_timer_check(struct task_struct *tsk) + return true; + } + ++#ifndef CONFIG_SCHED_ALT + if (dl_task(tsk) && tsk->dl.dl_overrun) + return true; ++#endif + + return false; + } +diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c +index 529590499b1f..d04bb99b4f0e 100644 +--- a/kernel/trace/trace_selftest.c ++++ b/kernel/trace/trace_selftest.c +@@ -1155,10 +1155,15 @@ static int trace_wakeup_test_thread(void *data) + { + /* Make this a -deadline thread */ + static const struct sched_attr attr = { ++#ifdef CONFIG_SCHED_ALT ++ /* No deadline on BMQ/PDS, use RR */ ++ .sched_policy = SCHED_RR, ++#else + .sched_policy = SCHED_DEADLINE, + .sched_runtime = 100000ULL, + .sched_deadline = 10000000ULL, + .sched_period = 10000000ULL ++#endif + }; + struct wakeup_test_data *x = data; + +diff --git a/kernel/workqueue.c b/kernel/workqueue.c +index 2989b57e154a..7313d9f5585f 100644 +--- a/kernel/workqueue.c ++++ b/kernel/workqueue.c +@@ -1114,6 +1114,7 @@ static bool kick_pool(struct worker_pool *pool) + + p = worker->task; + ++#ifndef CONFIG_SCHED_ALT + #ifdef CONFIG_SMP + /* + * Idle @worker is about to execute @work and waking up provides an +@@ -1139,6 +1140,8 @@ static bool kick_pool(struct worker_pool *pool) + get_work_pwq(work)->stats[PWQ_STAT_REPATRIATED]++; + } + #endif ++#endif /* !CONFIG_SCHED_ALT */ ++ + wake_up_process(p); + return true; + } +@@ -1263,7 +1266,11 @@ void wq_worker_running(struct task_struct *task) + * CPU intensive auto-detection cares about how long a work item hogged + * CPU without sleeping. Reset the starting timestamp on wakeup. + */ ++#ifdef CONFIG_SCHED_ALT ++ worker->current_at = worker->task->sched_time; ++#else + worker->current_at = worker->task->se.sum_exec_runtime; ++#endif + + WRITE_ONCE(worker->sleeping, 0); + } +@@ -1348,7 +1355,11 @@ void wq_worker_tick(struct task_struct *task) + * We probably want to make this prettier in the future. + */ + if ((worker->flags & WORKER_NOT_RUNNING) || READ_ONCE(worker->sleeping) || ++#ifdef CONFIG_SCHED_ALT ++ worker->task->sched_time - worker->current_at < ++#else + worker->task->se.sum_exec_runtime - worker->current_at < ++#endif + wq_cpu_intensive_thresh_us * NSEC_PER_USEC) + return; + +@@ -2559,7 +2570,11 @@ __acquires(&pool->lock) + worker->current_work = work; + worker->current_func = work->func; + worker->current_pwq = pwq; ++#ifdef CONFIG_SCHED_ALT ++ worker->current_at = worker->task->sched_time; ++#else + worker->current_at = worker->task->se.sum_exec_runtime; ++#endif + work_data = *work_data_bits(work); + worker->current_color = get_work_color(work_data); + |