diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-01 13:48:52 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-01 13:48:52 -0700 |
commit | 9a7e0a90a454a7826ecbca055a6ec9271b70c686 (patch) | |
tree | 4e432bee81d5a7a480241db62edec2edc40069d5 /kernel | |
parent | 57a315cd7198907326e691cc909df2beebc2420d (diff) | |
parent | 8ea9183db4ad8afbcb7089a77c23eaf965b0cacd (diff) |
Merge tag 'sched-core-2021-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Thomas Gleixner:
- Revert the printk format based wchan() symbol resolution as it can
leak the raw value in case that the symbol is not resolvable.
- Make wchan() more robust and work with all kind of unwinders by
enforcing that the task stays blocked while unwinding is in progress.
- Prevent sched_fork() from accessing an invalid sched_task_group
- Improve asymmetric packing logic
- Extend scheduler statistics to RT and DL scheduling classes and add
statistics for bandwith burst to the SCHED_FAIR class.
- Properly account SCHED_IDLE entities
- Prevent a potential deadlock when initial priority is assigned to a
newly created kthread. A recent change to plug a race between cpuset
and __sched_setscheduler() introduced a new lock dependency which is
now triggered. Break the lock dependency chain by moving the priority
assignment to the thread function.
- Fix the idle time reporting in /proc/uptime for NOHZ enabled systems.
- Improve idle balancing in general and especially for NOHZ enabled
systems.
- Provide proper interfaces for live patching so it does not have to
fiddle with scheduler internals.
- Add cluster aware scheduling support.
- A small set of tweaks for RT (irqwork, wait_task_inactive(), various
scheduler options and delaying mmdrop)
- The usual small tweaks and improvements all over the place
* tag 'sched-core-2021-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (69 commits)
sched/fair: Cleanup newidle_balance
sched/fair: Remove sysctl_sched_migration_cost condition
sched/fair: Wait before decaying max_newidle_lb_cost
sched/fair: Skip update_blocked_averages if we are defering load balance
sched/fair: Account update_blocked_averages in newidle_balance cost
x86: Fix __get_wchan() for !STACKTRACE
sched,x86: Fix L2 cache mask
sched/core: Remove rq_relock()
sched: Improve wake_up_all_idle_cpus() take #2
irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ on PREEMPT_RT
irq_work: Handle some irq_work in a per-CPU thread on PREEMPT_RT
irq_work: Allow irq_work_sync() to sleep if irq_work() no IRQ support.
sched/rt: Annotate the RT balancing logic irqwork as IRQ_WORK_HARD_IRQ
sched: Add cluster scheduler level for x86
sched: Add cluster scheduler level in core and related Kconfig for ARM64
topology: Represent clusters of CPUs within a die
sched: Disable -Wunused-but-set-variable
sched: Add wrapper for get_wchan() to keep task blocked
x86: Fix get_wchan() to support the ORC unwinder
proc: Use task_is_running() for wchan in /proc/$pid/stat
...
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/Kconfig.preempt | 32 | ||||
-rw-r--r-- | kernel/exit.c | 2 | ||||
-rw-r--r-- | kernel/fork.c | 2 | ||||
-rw-r--r-- | kernel/irq_work.c | 130 | ||||
-rw-r--r-- | kernel/kprobes.c | 8 | ||||
-rw-r--r-- | kernel/kthread.c | 16 | ||||
-rw-r--r-- | kernel/livepatch/transition.c | 95 | ||||
-rw-r--r-- | kernel/rcu/tasks.h | 12 | ||||
-rw-r--r-- | kernel/rcu/tree_stall.h | 8 | ||||
-rw-r--r-- | kernel/sched/Makefile | 4 | ||||
-rw-r--r-- | kernel/sched/core.c | 392 | ||||
-rw-r--r-- | kernel/sched/core_sched.c | 9 | ||||
-rw-r--r-- | kernel/sched/deadline.c | 99 | ||||
-rw-r--r-- | kernel/sched/debug.c | 101 | ||||
-rw-r--r-- | kernel/sched/fair.c | 496 | ||||
-rw-r--r-- | kernel/sched/features.h | 5 | ||||
-rw-r--r-- | kernel/sched/rt.c | 130 | ||||
-rw-r--r-- | kernel/sched/sched.h | 32 | ||||
-rw-r--r-- | kernel/sched/stats.c | 104 | ||||
-rw-r--r-- | kernel/sched/stats.h | 49 | ||||
-rw-r--r-- | kernel/sched/stop_task.c | 4 | ||||
-rw-r--r-- | kernel/sched/topology.c | 34 | ||||
-rw-r--r-- | kernel/smp.c | 12 |
23 files changed, 1199 insertions, 577 deletions
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt index 5876e30c5740..60f1bfc3c7b2 100644 --- a/kernel/Kconfig.preempt +++ b/kernel/Kconfig.preempt @@ -2,10 +2,11 @@ choice prompt "Preemption Model" - default PREEMPT_NONE + default PREEMPT_NONE_BEHAVIOUR -config PREEMPT_NONE +config PREEMPT_NONE_BEHAVIOUR bool "No Forced Preemption (Server)" + select PREEMPT_NONE if !PREEMPT_DYNAMIC help This is the traditional Linux preemption model, geared towards throughput. It will still provide good latencies most of the @@ -17,9 +18,10 @@ config PREEMPT_NONE raw processing power of the kernel, irrespective of scheduling latencies. -config PREEMPT_VOLUNTARY +config PREEMPT_VOLUNTARY_BEHAVIOUR bool "Voluntary Kernel Preemption (Desktop)" depends on !ARCH_NO_PREEMPT + select PREEMPT_VOLUNTARY if !PREEMPT_DYNAMIC help This option reduces the latency of the kernel by adding more "explicit preemption points" to the kernel code. These new @@ -35,12 +37,10 @@ config PREEMPT_VOLUNTARY Select this if you are building a kernel for a desktop system. -config PREEMPT +config PREEMPT_BEHAVIOUR bool "Preemptible Kernel (Low-Latency Desktop)" depends on !ARCH_NO_PREEMPT - select PREEMPTION - select UNINLINE_SPIN_UNLOCK if !ARCH_INLINE_SPIN_UNLOCK - select PREEMPT_DYNAMIC if HAVE_PREEMPT_DYNAMIC + select PREEMPT help This option reduces the latency of the kernel by making all kernel code (that is not executing in a critical section) @@ -58,7 +58,7 @@ config PREEMPT config PREEMPT_RT bool "Fully Preemptible Kernel (Real-Time)" - depends on EXPERT && ARCH_SUPPORTS_RT + depends on EXPERT && ARCH_SUPPORTS_RT && !PREEMPT_DYNAMIC select PREEMPTION help This option turns the kernel into a real-time kernel by replacing @@ -75,6 +75,17 @@ config PREEMPT_RT endchoice +config PREEMPT_NONE + bool + +config PREEMPT_VOLUNTARY + bool + +config PREEMPT + bool + select PREEMPTION + select UNINLINE_SPIN_UNLOCK if !ARCH_INLINE_SPIN_UNLOCK + config PREEMPT_COUNT bool @@ -83,7 +94,10 @@ config PREEMPTION select PREEMPT_COUNT config PREEMPT_DYNAMIC - bool + bool "Preemption behaviour defined on boot" + depends on HAVE_PREEMPT_DYNAMIC + select PREEMPT + default y help This option allows to define the preemption model on the kernel command line parameter and thus override the default preemption diff --git a/kernel/exit.c b/kernel/exit.c index a53863dafb3d..50f1692c732d 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -63,6 +63,7 @@ #include <linux/rcuwait.h> #include <linux/compat.h> #include <linux/io_uring.h> +#include <linux/kprobes.h> #include <linux/uaccess.h> #include <asm/unistd.h> @@ -167,6 +168,7 @@ static void delayed_put_task_struct(struct rcu_head *rhp) { struct task_struct *tsk = container_of(rhp, struct task_struct, rcu); + kprobe_flush_task(tsk); perf_event_delayed_put(tsk); trace_sched_process_free(tsk); put_task_struct(tsk); diff --git a/kernel/fork.c b/kernel/fork.c index 67679e3933f2..8e9feeef555e 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2404,7 +2404,7 @@ static __latent_entropy struct task_struct *copy_process( write_unlock_irq(&tasklist_lock); proc_fork_connector(p); - sched_post_fork(p); + sched_post_fork(p, args); cgroup_post_fork(p, args); perf_event_fork(p); diff --git a/kernel/irq_work.c b/kernel/irq_work.c index db8c248ebc8c..f7df715ec28e 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -18,11 +18,36 @@ #include <linux/cpu.h> #include <linux/notifier.h> #include <linux/smp.h> +#include <linux/smpboot.h> #include <asm/processor.h> #include <linux/kasan.h> static DEFINE_PER_CPU(struct llist_head, raised_list); static DEFINE_PER_CPU(struct llist_head, lazy_list); +static DEFINE_PER_CPU(struct task_struct *, irq_workd); + +static void wake_irq_workd(void) +{ + struct task_struct *tsk = __this_cpu_read(irq_workd); + + if (!llist_empty(this_cpu_ptr(&lazy_list)) && tsk) + wake_up_process(tsk); +} + +#ifdef CONFIG_SMP +static void irq_work_wake(struct irq_work *entry) +{ + wake_irq_workd(); +} + +static DEFINE_PER_CPU(struct irq_work, irq_work_wakeup) = + IRQ_WORK_INIT_HARD(irq_work_wake); +#endif + +static int irq_workd_should_run(unsigned int cpu) +{ + return !llist_empty(this_cpu_ptr(&lazy_list)); +} /* * Claim the entry so that no one else will poke at it. @@ -52,15 +77,29 @@ void __weak arch_irq_work_raise(void) /* Enqueue on current CPU, work must already be claimed and preempt disabled */ static void __irq_work_queue_local(struct irq_work *work) { + struct llist_head *list; + bool rt_lazy_work = false; + bool lazy_work = false; + int work_flags; + + work_flags = atomic_read(&work->node.a_flags); + if (work_flags & IRQ_WORK_LAZY) + lazy_work = true; + else if (IS_ENABLED(CONFIG_PREEMPT_RT) && + !(work_flags & IRQ_WORK_HARD_IRQ)) + rt_lazy_work = true; + + if (lazy_work || rt_lazy_work) + list = this_cpu_ptr(&lazy_list); + else + list = this_cpu_ptr(&raised_list); + + if (!llist_add(&work->node.llist, list)) + return; + /* If the work is "lazy", handle it from next tick if any */ - if (atomic_read(&work->node.a_flags) & IRQ_WORK_LAZY) { - if (llist_add(&work->node.llist, this_cpu_ptr(&lazy_list)) && - tick_nohz_tick_stopped()) - arch_irq_work_raise(); - } else { - if (llist_add(&work->node.llist, this_cpu_ptr(&raised_list))) - arch_irq_work_raise(); - } + if (!lazy_work || tick_nohz_tick_stopped()) + arch_irq_work_raise(); } /* Enqueue the irq work @work on the current CPU */ @@ -104,17 +143,34 @@ bool irq_work_queue_on(struct irq_work *work, int cpu) if (cpu != smp_processor_id()) { /* Arch remote IPI send/receive backend aren't NMI safe */ WARN_ON_ONCE(in_nmi()); + + /* + * On PREEMPT_RT the items which are not marked as + * IRQ_WORK_HARD_IRQ are added to the lazy list and a HARD work + * item is used on the remote CPU to wake the thread. + */ + if (IS_ENABLED(CONFIG_PREEMPT_RT) && + !(atomic_read(&work->node.a_flags) & IRQ_WORK_HARD_IRQ)) { + + if (!llist_add(&work->node.llist, &per_cpu(lazy_list, cpu))) + goto out; + + work = &per_cpu(irq_work_wakeup, cpu); + if (!irq_work_claim(work)) + goto out; + } + __smp_call_single_queue(cpu, &work->node.llist); } else { __irq_work_queue_local(work); } +out: preempt_enable(); return true; #endif /* CONFIG_SMP */ } - bool irq_work_needs_cpu(void) { struct llist_head *raised, *lazy; @@ -160,6 +216,10 @@ void irq_work_single(void *arg) * else claimed it meanwhile. */ (void)atomic_cmpxchg(&work->node.a_flags, flags, flags & ~IRQ_WORK_BUSY); + + if ((IS_ENABLED(CONFIG_PREEMPT_RT) && !irq_work_is_hard(work)) || + !arch_irq_work_has_interrupt()) + rcuwait_wake_up(&work->irqwait); } static void irq_work_run_list(struct llist_head *list) @@ -167,7 +227,12 @@ static void irq_work_run_list(struct llist_head *list) struct irq_work *work, *tmp; struct llist_node *llnode; - BUG_ON(!irqs_disabled()); + /* + * On PREEMPT_RT IRQ-work which is not marked as HARD will be processed + * in a per-CPU thread in preemptible context. Only the items which are + * marked as IRQ_WORK_HARD_IRQ will be processed in hardirq context. + */ + BUG_ON(!irqs_disabled() && !IS_ENABLED(CONFIG_PREEMPT_RT)); if (llist_empty(list)) return; @@ -184,7 +249,10 @@ static void irq_work_run_list(struct llist_head *list) void irq_work_run(void) { irq_work_run_list(this_cpu_ptr(&raised_list)); - irq_work_run_list(this_cpu_ptr(&lazy_list)); + if (!IS_ENABLED(CONFIG_PREEMPT_RT)) + irq_work_run_list(this_cpu_ptr(&lazy_list)); + else + wake_irq_workd(); } EXPORT_SYMBOL_GPL(irq_work_run); @@ -194,7 +262,11 @@ void irq_work_tick(void) if (!llist_empty(raised) && !arch_irq_work_has_interrupt()) irq_work_run_list(raised); - irq_work_run_list(this_cpu_ptr(&lazy_list)); + + if (!IS_ENABLED(CONFIG_PREEMPT_RT)) + irq_work_run_list(this_cpu_ptr(&lazy_list)); + else + wake_irq_workd(); } /* @@ -204,8 +276,42 @@ void irq_work_tick(void) void irq_work_sync(struct irq_work *work) { lockdep_assert_irqs_enabled(); + might_sleep(); + + if ((IS_ENABLED(CONFIG_PREEMPT_RT) && !irq_work_is_hard(work)) || + !arch_irq_work_has_interrupt()) { + rcuwait_wait_event(&work->irqwait, !irq_work_is_busy(work), + TASK_UNINTERRUPTIBLE); + return; + } while (irq_work_is_busy(work)) cpu_relax(); } EXPORT_SYMBOL_GPL(irq_work_sync); + +static void run_irq_workd(unsigned int cpu) +{ + irq_work_run_list(this_cpu_ptr(&lazy_list)); +} + +static void irq_workd_setup(unsigned int cpu) +{ + sched_set_fifo_low(current); +} + +static struct smp_hotplug_thread irqwork_threads = { + .store = &irq_workd, + .setup = irq_workd_setup, + .thread_should_run = irq_workd_should_run, + .thread_fn = run_irq_workd, + .thread_comm = "irq_work/%u", +}; + +static __init int irq_work_init_threads(void) +{ + if (IS_ENABLED(CONFIG_PREEMPT_RT)) + BUG_ON(smpboot_register_percpu_thread(&irqwork_threads)); + return 0; +} +early_initcall(irq_work_init_threads); diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 790a573bbe00..9a38e7581a5c 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1250,10 +1250,10 @@ void kprobe_busy_end(void) } /* - * This function is called from finish_task_switch when task tk becomes dead, - * so that we can recycle any function-return probe instances associated - * with this task. These left over instances represent probed functions - * that have been called but will never return. + * This function is called from delayed_put_task_struct() when a task is + * dead and cleaned up to recycle any function-return probe instances + * associated with this task. These left over instances represent probed + * functions that have been called but will never return. */ void kprobe_flush_task(struct task_struct *tk) { diff --git a/kernel/kthread.c b/kernel/kthread.c index 5b37a8567168..4a4d7092a2d8 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -270,6 +270,7 @@ EXPORT_SYMBOL_GPL(kthread_parkme); static int kthread(void *_create) { + static const struct sched_param param = { .sched_priority = 0 }; /* Copy data: it's on kthread's stack */ struct kthread_create_info *create = _create; int (*threadfn)(void *data) = create->threadfn; @@ -300,6 +301,13 @@ static int kthread(void *_create) init_completion(&self->parked); current->vfork_done = &self->exited; + /* + * The new thread inherited kthreadd's priority and CPU mask. Reset + * back to default in case they have been changed. + */ + sched_setscheduler_nocheck(current, SCHED_NORMAL, ¶m); + set_cpus_allowed_ptr(current, housekeeping_cpumask(HK_FLAG_KTHREAD)); + /* OK, tell user we're spawned, wait for stop or wakeup */ __set_current_state(TASK_UNINTERRUPTIBLE); create->result = current; @@ -397,7 +405,6 @@ struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data), } task = create->result; if (!IS_ERR(task)) { - static const struct sched_param param = { .sched_priority = 0 }; char name[TASK_COMM_LEN]; /* @@ -406,13 +413,6 @@ struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data), */ vsnprintf(name, sizeof(name), namefmt, args); set_task_comm(task, name); - /* - * root may have changed our (kthreadd's) priority or CPU mask. - * The kernel thread should not inherit these properties. - */ - sched_setscheduler_nocheck(task, SCHED_NORMAL, ¶m); - set_cpus_allowed_ptr(task, - housekeeping_cpumask(HK_FLAG_KTHREAD)); } kfree(create); return task; diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c index 291b857a6e20..5683ac0d2566 100644 --- a/kernel/livepatch/transition.c +++ b/kernel/livepatch/transition.c @@ -13,7 +13,6 @@ #include "core.h" #include "patch.h" #include "transition.h" -#include "../sched/sched.h" #define MAX_STACK_ENTRIES 100 #define STACK_ERR_BUF_SIZE 128 @@ -240,7 +239,7 @@ static int klp_check_stack_func(struct klp_func *func, unsigned long *entries, * Determine whether it's safe to transition the task to the target patch state * by looking for any to-be-patched or to-be-unpatched functions on its stack. */ -static int klp_check_stack(struct task_struct *task, char *err_buf) +static int klp_check_stack(struct task_struct *task, const char **oldname) { static unsigned long entries[MAX_STACK_ENTRIES]; struct klp_object *obj; @@ -248,12 +247,8 @@ static int klp_check_stack(struct task_struct *task, char *err_buf) int ret, nr_entries; ret = stack_trace_save_tsk_reliable(task, entries, ARRAY_SIZE(entries)); - if (ret < 0) { - snprintf(err_buf, STACK_ERR_BUF_SIZE, - "%s: %s:%d has an unreliable stack\n", - __func__, task->comm, task->pid); - return ret; - } + if (ret < 0) + return -EINVAL; nr_entries = ret; klp_for_each_object(klp_transition_patch, obj) { @@ -262,11 +257,8 @@ static int klp_check_stack(struct task_struct *task, char *err_buf) klp_for_each_func(obj, func) { ret = klp_check_stack_func(func, entries, nr_entries); if (ret) { - snprintf(err_buf, STACK_ERR_BUF_SIZE, - "%s: %s:%d is sleeping on function %s\n", - __func__, task->comm, task->pid, - func->old_name); - return ret; + *oldname = func->old_name; + return -EADDRINUSE; } } } @@ -274,6 +266,22 @@ static int klp_check_stack(struct task_struct *task, char *err_buf) return 0; } +static int klp_check_and_switch_task(struct task_struct *task, void *arg) +{ + int ret; + + if (task_curr(task) && task != current) + return -EBUSY; + + ret = klp_check_stack(task, arg); + if (ret) + return ret; + + clear_tsk_thread_flag(task, TIF_PATCH_PENDING); + task->patch_state = klp_target_state; + return 0; +} + /* * Try to safely switch a task to the target patch state. If it's currently * running, or it's sleeping on a to-be-patched or to-be-unpatched function, or @@ -281,13 +289,8 @@ static int klp_check_stack(struct task_struct *task, char *err_buf) */ static bool klp_try_switch_task(struct task_struct *task) { - static char err_buf[STACK_ERR_BUF_SIZE]; - struct rq *rq; - struct rq_flags flags; + const char *old_name; int ret; - bool success = false; - - err_buf[0] = '\0'; /* check if this task has already switched over */ if (task->patch_state == klp_target_state) @@ -305,36 +308,31 @@ static bool klp_try_switch_task(struct task_struct *task) * functions. If all goes well, switch the task to the target patch * state. */ - rq = task_rq_lock(task, &flags); + ret = task_call_func(task, klp_check_and_switch_task, &old_name); + switch (ret) { + case 0: /* success */ + break; - if (task_running(rq, task) && task != current) { - snprintf(err_buf, STACK_ERR_BUF_SIZE, - "%s: %s:%d is running\n", __func__, task->comm, - task->pid); - goto done; + case -EBUSY: /* klp_check_and_switch_task() */ + pr_debug("%s: %s:%d is running\n", + __func__, task->comm, task->pid); + break; + case -EINVAL: /* klp_check_and_switch_task() */ + pr_debug("%s: %s:%d has an unreliable stack\n", + __func__, task->comm, task->pid); + break; + case -EADDRINUSE: /* klp_check_and_switch_task() */ + pr_debug("%s: %s:%d is sleeping on function %s\n", + __func__, task->comm, task->pid, old_name); + break; + + default: + pr_debug("%s: Unknown error code (%d) when trying to switch %s:%d\n", + __func__, ret, task->comm, task->pid); + break; } - ret = klp_check_stack(task, err_buf); - if (ret) - goto done; - - success = true; - - clear_tsk_thread_flag(task, TIF_PATCH_PENDING); - task->patch_state = klp_target_state; - -done: - task_rq_unlock(rq, task, &flags); - - /* - * Due to console deadlock issues, pr_debug() can't be used while - * holding the task rq lock. Instead we have to use a temporary buffer - * and print the debug message after releasing the lock. - */ - if (err_buf[0] != '\0') - pr_debug("%s", err_buf); - - return success; + return !ret; } /* @@ -415,8 +413,11 @@ void klp_try_complete_transition(void) for_each_possible_cpu(cpu) { task = idle_task(cpu); if (cpu_online(cpu)) { - if (!klp_try_switch_task(task)) + if (!klp_try_switch_task(task)) { complete = false; + /* Make idle task go through the main loop. */ + wake_up_if_idle(cpu); + } } else if (task->patch_state != klp_target_state) { /* offline idle tasks can be switched immediately */ clear_tsk_thread_flag(task, TIF_PATCH_PENDING); diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index 806160c44b17..171bc848e8e3 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -928,7 +928,7 @@ reset_ipi: } /* Callback function for scheduler to check locked-down task. */ -static bool trc_inspect_reader(struct task_struct *t, void *arg) +static int trc_inspect_reader(struct task_struct *t, void *arg) { int cpu = task_cpu(t); bool in_qs = false; @@ -939,7 +939,7 @@ static bool trc_inspect_reader(struct task_struct *t, void *arg) // If no chance of heavyweight readers, do it the hard way. if (!ofl && !IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB)) - return false; + return -EINVAL; // If heavyweight readers are enabled on the remote task, // we can inspect its state despite its currently running. @@ -947,7 +947,7 @@ static bool trc_inspect_reader(struct task_struct *t, void *arg) n_heavy_reader_attempts++; if (!ofl && // Check for "running" idle tasks on offline CPUs. !rcu_dynticks_zero_in_eqs(cpu, &t->trc_reader_nesting)) - return false; // No quiescent state, do it the hard way. + return -EINVAL; // No quiescent state, do it the hard way. n_heavy_reader_updates++; if (ofl) n_heavy_reader_ofl_updates++; @@ -962,7 +962,7 @@ static bool trc_inspect_reader(struct task_struct *t, void *arg) t->trc_reader_checked = true; if (in_qs) - return true; // Already in quiescent state, done!!! + return 0; // Already in quiescent state, done!!! // The task is in a read-side critical section, so set up its // state so that it will awaken the grace-period kthread upon exit @@ -970,7 +970,7 @@ static bool trc_inspect_reader(struct task_struct *t, void *arg) atomic_inc(&trc_n_readers_need_end); // One more to wait on. WARN_ON_ONCE(READ_ONCE(t->trc_reader_special.b.need_qs)); WRITE_ONCE(t->trc_reader_special.b.need_qs, true); - return true; + return 0; } /* Attempt to extract the state for the specified task. */ @@ -992,7 +992,7 @@ static void trc_wait_for_one_reader(struct task_struct *t, // Attempt to nail down the task for inspection. get_task_struct(t); - if (try_invoke_on_locked_down_task(t, trc_inspect_reader, NULL)) { + if (!task_call_func(t, trc_inspect_reader, NULL)) { put_task_struct(t); return; } diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index 677ee3d8671b..5e2fa6fd97f1 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -240,16 +240,16 @@ struct rcu_stall_chk_rdr { * Report out the state of a not-running task that is stalling the * current RCU grace period. */ -static bool check_slow_task(struct task_struct *t, void *arg) +static int check_slow_task(struct task_struct *t, void *arg) { struct rcu_stall_chk_rdr *rscrp = arg; if (task_curr(t)) - return false; // It is running, so decline to inspect it. + return -EBUSY; // It is running, so decline to inspect it. rscrp->nesting = t->rcu_read_lock_nesting; rscrp->rs = t->rcu_read_unlock_special; rscrp->on_blkd_list = !list_empty(&t->rcu_node_entry); - return true; + return 0; } /* @@ -283,7 +283,7 @@ static int rcu_print_task_stall(struct rcu_node *rnp, unsigned long flags) raw_spin_unlock_irqrestore_rcu_node(rnp, flags); while (i) { t = ts[--i]; - if (!try_invoke_on_locked_down_task(t, check_slow_task, &rscr)) + if (task_call_func(t, check_slow_task, &rscr)) pr_cont(" P%d", t->pid); else pr_cont(" P%d/%d:%c%c%c%c", diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile index 978fcfca5871..c7421f2d05e1 100644 --- a/kernel/sched/Makefile +++ b/kernel/sched/Makefile @@ -3,6 +3,10 @@ ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_clock.o = $(CC_FLAGS_FTRACE) endif +# The compilers are complaining about unused variables inside an if(0) scope +# block. This is daft, shut them up. +ccflags-y += $(call cc-disable-warning, unused-but-set-variable) + # These files are disabled because they produce non-interesting flaky coverage # that is not a function of syscall inputs. E.g. involuntary context switches. KCOV_INSTRUMENT := n diff --git a/kernel/sched/core.c b/kernel/sched/core.c index bc0e242e434c..523fd602ea90 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -74,7 +74,11 @@ __read_mostly int sysctl_resched_latency_warn_once = 1; * Number of tasks to iterate in a single balance run. * Limited because this is done with IRQs disabled. */ +#ifdef CONFIG_PREEMPT_RT +const_debug unsigned int sysctl_sched_nr_migrate = 8; +#else const_debug unsigned int sysctl_sched_nr_migrate = 32; +#endif /* * period over which we measure -rt task CPU usage in us. @@ -1962,6 +1966,25 @@ 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; +} + static inline void enqueue_task(struct rq *rq, struct task_struct *p, int flags) { if (!(flags & ENQUEUE_NOCLOCK)) @@ -3251,7 +3274,7 @@ unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state ktime_t to = NSEC_PER_SEC / HZ; set_current_state(TASK_UNINTERRUPTIBLE); - schedule_hrtimeout(&to, HRTIMER_MODE_REL); + schedule_hrtimeout(&to, HRTIMER_MODE_REL_HARD); continue; } @@ -3489,11 +3512,11 @@ ttwu_stat(struct task_struct *p, int cpu, int wake_flags) #ifdef CONFIG_SMP if (cpu == rq->cpu) { __schedstat_inc(rq->ttwu_local); - __schedstat_inc(p->se.statistics.nr_wakeups_local); + __schedstat_inc(p->stats.nr_wakeups_local); } else { struct sched_domain *sd; - __schedstat_inc(p->se.statistics.nr_wakeups_remote); + __schedstat_inc(p->stats.nr_wakeups_remote); rcu_read_lock(); for_each_domain(rq->cpu, sd) { if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { @@ -3505,14 +3528,14 @@ ttwu_stat(struct task_struct *p, int cpu, int wake_flags) } if (wake_flags & WF_MIGRATED) - __schedstat_inc(p->se.statistics.nr_wakeups_migrate); + __schedstat_inc(p->stats.nr_wakeups_migrate); #endif /* CONFIG_SMP */ __schedstat_inc(rq->ttwu_count); - __schedstat_inc(p->se.statistics.nr_wakeups); + __schedstat_inc(p->stats.nr_wakeups); if (wake_flags & WF_SYNC) - __schedstat_inc(p->se.statistics.nr_wakeups_sync); + __schedstat_inc(p->stats.nr_wakeups_sync); } /* @@ -3691,15 +3714,11 @@ void wake_up_if_idle(int cpu) if (!is_idle_task(rcu_dereference(rq->curr))) goto out; - if (set_nr_if_polling(rq->idle)) { - trace_sched_wake_idle_without_ipi(cpu); - } else { - rq_lock_irqsave(rq, &rf); - if (is_idle_task(rq->curr)) - smp_send_reschedule(cpu); - /* Else CPU is not idle, do nothing here: */ - rq_unlock_irqrestore(rq, &rf); - } + rq_lock_irqsave(rq, &rf); + if (is_idle_task(rq->curr)) + resched_curr(rq); + /* Else CPU is not idle, do nothing here: */ + rq_unlock_irqrestore(rq, &rf); out: rcu_read_unlock(); @@ -4106,46 +4125,61 @@ out: } /** - * try_invoke_on_locked_down_task - Invoke a function on task in fixed state + * 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. * - * If the specified task can be quickly locked into a definite state - * (either sleeping or on a given runqueue), arrange to keep it in that - * state while invoking @func(@arg). 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. + * 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: - * @false if the task slipped out from under the locks. - * @true if the task was locked onto a runqueue or is sleeping. - * However, @func can override this by returning @false. + * Whatever @func returns */ -bool try_invoke_on_locked_down_task(struct task_struct *p, bool (*func)(struct task_struct *t, void *arg), void *arg) +int task_call_func(struct task_struct *p, task_call_f func, void *arg) { + struct rq *rq = NULL; + unsigned int state; struct rq_flags rf; - bool ret = false; - struct rq *rq; + int ret; raw_spin_lock_irqsave(&p->pi_lock, rf.flags); - if (p->on_rq) { + + state = READ_ONCE(p->__state); + + /* + * 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(); + + /* + * 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 || p->on_rq) rq = __task_rq_lock(p, &rf); - if (task_rq(p) == rq) - ret = func(p, arg); + + /* + * 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) rq_unlock(rq, &rf); - } else { - switch (READ_ONCE(p->__state)) { - case TASK_RUNNING: - case TASK_WAKING: - break; - default: - smp_rmb(); // See smp_rmb() comment in try_to_wake_up(). - if (!p->on_rq) - ret = func(p, arg); - } - } + raw_spin_unlock_irqrestore(&p->pi_lock, rf.flags); return ret; } @@ -4196,7 +4230,7 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p) #ifdef CONFIG_SCHEDSTATS /* Even if schedstat is disabled, there should not be garbage */ - memset(&p->se.statistics, 0, sizeof(p->se.statistics)); + memset(&p->stats, 0, sizeof(p->stats)); #endif RB_CLEAR_NODE(&p->dl.rb_node); @@ -4328,8 +4362,6 @@ int sysctl_schedstats(struct ctl_table *table, int write, void *buffer, */ int sched_fork(unsigned long clone_flags, struct task_struct *p) { - unsigned long flags; - __sched_fork(clone_flags, p); /* * We mark the process as NEW here. This guarantees that @@ -4375,24 +4407,6 @@ int sched_fork(unsigned long clone_flags, struct task_struct *p) init_entity_runnable_average(&p->se); - /* - * The child is not yet in the pid-hash so no cgroup attach races, - * and the cgroup is pinned to this child due to cgroup_fork() - * is ran before sched_fork(). - * - * Silence PROVE_RCU. - */ - raw_spin_lock_irqsave(&p->pi_lock, flags); - 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()); - if (p->sched_class->task_fork) - p->sched_class->task_fork(p); - raw_spin_unlock_irqrestore(&p->pi_lock, flags); - #ifdef CONFIG_SCHED_INFO if (likely(sched_info_on())) memset(&p->sched_info, 0, sizeof(p->sched_info)); @@ -4408,8 +4422,29 @@ int sched_fork(unsigned long clone_flags, struct task_struct *p) return 0; } -void sched_post_fork(struct task_struct *p) +void sched_post_fork(struct task_struct *p, struct kernel_clone_args *kargs) { + unsigned long flags; +#ifdef CONFIG_CGROUP_SCHED + struct task_group *tg; +#endif + + raw_spin_lock_irqsave(&p->pi_lock, flags); +#ifdef CONFIG_CGROUP_SCHED + tg = container_of(kargs->cset->subsys[cpu_cgrp_id], + struct task_group, css); + p->sched_task_group = autogroup_task_group(p, tg); +#endif + 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()); + if (p->sched_class->task_fork) + p->sched_class->task_fork(p); + raw_spin_unlock_irqrestore(&p->pi_lock, flags); + uclamp_post_fork(p); } @@ -4836,18 +4871,12 @@ static struct rq *finish_task_switch(struct task_struct *prev) */ if (mm) { membarrier_mm_sync_core_before_usermode(mm); - mmdrop(mm); + mmdrop_sched(mm); } if (unlikely(prev_state == TASK_DEAD)) { if (prev->sched_class->task_dead) prev->sched_class->task_dead(prev); - /* - * Remove function-return probe instances associated with this - * task and put them back on the free list. - */ - kprobe_flush_task(prev); - /* Task is done with its stack. */ put_task_stack(prev); @@ -5580,8 +5609,7 @@ restart: return p; } - /* The idle class should always have a runnable task: */ - BUG(); + BUG(); /* The idle class should always have a runnable task. */ } #ifdef CONFIG_SCHED_CORE @@ -5603,54 +5631,18 @@ static inline bool cookie_match(struct task_struct *a, struct task_struct *b) return a->core_cookie == b->core_cookie; } -// XXX fairness/fwd progress conditions -/* - * Returns - * - NULL if there is no runnable task for this class. - * - the highest priority task for this runqueue if it matches - * rq->core->core_cookie or its priority is greater than max. - * - Else returns idle_task. - */ -static struct task_struct * -pick_task(struct rq *rq, const struct sched_class *class, struct task_struct *max, bool in_fi) +static inline struct task_struct *pick_task(struct rq *rq) { - struct task_struct *class_pick, *cookie_pick; - unsigned long cookie = rq->core->core_cookie; - - class_pick = class->pick_task(rq); - if (!class_pick) - return NULL; - - if (!cookie) { - /* - * If class_pick is tagged, return it only if it has - * higher priority than max. - */ - if (max && class_pick->core_cookie && - prio_less(class_pick, max, in_fi)) - return idle_sched_class.pick_task(rq); + const struct sched_class *class; + struct task_struct *p; - return class_pick; + for_each_class(class) { + p = class->pick_task(rq); + if (p) + return p; } - /* - * If class_pick is idle or matches cookie, return early. - */ - if (cookie_equals(class_pick, cookie)) - return class_pick; - - cookie_pick = sched_core_find(rq, cookie); - - /* - * If class > max && class > cookie, it is the highest priority task on - * the core (so far) and it must be selected, otherwise we must go with - * the cookie pick in order to satisfy the constraint. - */ - if (prio_less(cookie_pick, class_pick, in_fi) && - (!max || prio_less(max, class_pick, in_fi))) - return class_pick; - - return cookie_pick; + BUG(); /* The idle class should always have a runnable task. */ } extern void task_vruntime_update(struct rq *rq, struct task_struct *p, bool in_fi); @@ -5658,11 +5650,12 @@ extern void task_vruntime_update(struct rq *rq, struct task_struct *p, bool in_f static struct task_struct * pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) { - struct task_struct *next, *max = NULL; - const struct sched_class *class; + struct task_struct *next, *p, *max = NULL; const struct cpumask *smt_mask; bool fi_before = false; - int i, j, cpu, occ = 0; + unsigned long cookie; + int i, cpu, occ = 0; + struct rq *rq_i; bool need_sync; if (!sched_core_enabled(rq)) @@ -5735,12 +5728,7 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) * and there are no cookied tasks running on siblings. */ if (!need_sync) { - for_each_class(class) { - next = class->pick_task(rq); - if (next) - break; - } - + next = pick_task(rq); if (!next->core_cookie) { rq->core_pick = NULL; /* @@ -5753,76 +5741,51 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) } } - for_each_cpu(i, smt_mask) { - struct rq *rq_i = cpu_rq(i); - - rq_i->core_pick = NULL; + /* + * For each thread: do the regular task pick and find the max prio task + * amongst them. + * + * Tie-break prio towards the current CPU + */ + for_each_cpu_wrap(i, smt_mask, cpu) { + rq_i = cpu_rq(i); if (i != cpu) update_rq_clock(rq_i); + + p = rq_i->core_pick = pick_task(rq_i); + if (!max || prio_less(max, p, fi_before)) + max = p; } + cookie = rq->core->core_cookie = max->core_cookie; + /* - * Try and select tasks for each sibling in descending sched_class - * order. + * For each thread: try and find a runnable task that matches @max or + * force idle. */ - for_each_class(class) { -again: - for_each_cpu_wrap(i, smt_mask, cpu) { - struct rq *rq_i = cpu_rq(i); - struct task_struct *p; - - if (rq_i->core_pick) - continue; + for_each_cpu(i, smt_mask) { + rq_i = cpu_rq(i); + p = rq_i->core_pick; - /* - * If this sibling doesn't yet have a suitable task to - * run; ask for the most eligible task, given the - * highest priority task already selected for this - * core. - */ - p = pick_task(rq_i, class, max, fi_before); + if (!cookie_equals(p, cookie)) { + p = NULL; + if (cookie) + p = sched_core_find(rq_i, cookie); if (!p) - continue; + p = idle_sched_class.pick_task(rq_i); + } - if (!is_task_rq_idle(p)) - occ++; + rq_i->core_pick = p; - rq_i->core_pick = p; - if (rq_i->idle == p && rq_i->nr_running) { + if (p == rq_i->idle) { + if (rq_i->nr_running) { rq->core->core_forceidle = true; if (!fi_before) rq->core->core_forceidle_seq++; } - - /* - * If this new candidate is of higher priority than the - * previous; and they're incompatible; we need to wipe - * the slate and start over. pick_task makes sure that - * p's priority is more than max if it doesn't match - * max's cookie. - * - * NOTE: this is a linear max-filter and is thus bounded - * in execution time. - */ - if (!max || !cookie_match(max, p)) { - struct task_struct *old_max = max; - - rq->core->core_cookie = p->core_cookie; - max = p; - - if (old_max) { - rq->core->core_forceidle = false; - for_each_cpu(j, smt_mask) { - if (j == i) - continue; - - cpu_rq(j)->core_pick = NULL; - } - occ = 1; - goto again; - } - } + } else { + occ++; } } @@ -5842,7 +5805,7 @@ again: * non-matching user state. */ for_each_cpu(i, smt_mask) { - struct rq *rq_i = cpu_rq(i); + rq_i = cpu_rq(i); /* * An online sibling might have gone offline before a task @@ -6319,20 +6282,14 @@ static inline void sched_submit_work(struct task_struct *tsk) task_flags = tsk->flags; /* - * If a worker went to sleep, notify and ask workqueue whether - * it wants to wake up a task to maintain concurrency. - * As this function is called inside the schedule() context, - * we disable preemption to avoid it calling schedule() again - * in the possible wakeup of a kworker and because wq_worker_sleeping() - * requires it. + * 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 | PF_IO_WORKER)) { - preempt_disable(); if (task_flags & PF_WQ_WORKER) wq_worker_sleeping(tsk); else io_wq_worker_sleeping(tsk); - preempt_enable_no_resched(); } if (tsk_is_pi_blocked(tsk)) @@ -6586,12 +6543,13 @@ EXPORT_STATIC_CALL_TRAMP(preempt_schedule_notrace); */ enum { - preempt_dynamic_none = 0, + preempt_dynamic_undefined = -1, + preempt_dynamic_none, preempt_dynamic_voluntary, preempt_dynamic_full, }; -int preempt_dynamic_mode = preempt_dynamic_full; +int preempt_dynamic_mode = preempt_dynamic_undefined; int sched_dynamic_mode(const char *str) { @@ -6664,7 +6622,27 @@ static int __init setup_preempt_mode(char *str) } __setup("preempt=", setup_preempt_mode); -#endif /* CONFIG_PREEMPT_DYNAMIC */ +static void __init preempt_dynamic_init(void) +{ + if (preempt_dynamic_mode == preempt_dynamic_undefined) { + if (IS_ENABLED(CONFIG_PREEMPT_NONE_BEHAVIOUR)) { + sched_dynamic_update(preempt_dynamic_none); + } else if (IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY_BEHAVIOUR)) { + sched_dynamic_update(preempt_dynamic_voluntary); + } else { + /* Default static call setting, nothing to do */ + WARN_ON_ONCE(!IS_ENABLED(CONFIG_PREEMPT_BEHAVIOUR)); + preempt_dynamic_mode = preempt_dynamic_full; + pr_info("Dynamic Preempt: full\n"); + } + } +} + +#else /* !CONFIG_PREEMPT_DYNAMIC */ + +static inline void preempt_dynamic_init(void) { } + +#endif /* #ifdef CONFIG_PREEMPT_DYNAMIC */ /* * This is the entry point to schedule() from kernel preemption @@ -9466,6 +9444,8 @@ void __init sched_init(void) init_uclamp(); + preempt_dynamic_init(); + scheduler_running = 1; } @@ -9640,9 +9620,9 @@ void normalize_rt_tasks(void) continue; p->se.exec_start = 0; - schedstat_set(p->se.statistics.wait_start, 0); - schedstat_set(p->se.statistics.sleep_start, 0); - schedstat_set(p->se.statistics.block_start, 0); + schedstat_set(p->stats.wait_start, 0); + schedstat_set(p->stats.sleep_start, 0); + schedstat_set(p->stats.block_start, 0); if (!dl_task(p) && !rt_task(p)) { /* @@ -10484,15 +10464,21 @@ static int cpu_cfs_stat_show(struct seq_file *sf, void *v) seq_printf(sf, "throttled_time %llu\n", cfs_b->throttled_time); if (schedstat_enabled() && tg != &root_task_group) { + struct sched_statistics *stats; u64 ws = 0; int i; - for_each_possible_cpu(i) - ws += schedstat_val(tg->se[i]->statistics.wait_sum); + for_each_possible_cpu(i) { + stats = __schedstats_from_se(tg->se[i]); + ws += schedstat_val(stats->wait_sum); + } seq_printf(sf, "wait_sum %llu\n", ws); } + seq_printf(sf, "nr_bursts %d\n", cfs_b->nr_burst); + seq_printf(sf, "burst_time %llu\n", cfs_b->burst_time); + return 0; } #endif /* CONFIG_CFS_BANDWIDTH */ @@ -10608,16 +10594,20 @@ static int cpu_extra_stat_show(struct seq_file *sf, { struct task_group *tg = css_tg(css); struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; - u64 throttled_usec; + u64 throttled_usec, burst_usec; throttled_usec = cfs_b->throttled_time; do_div(throttled_usec, NSEC_PER_USEC); + burst_usec = cfs_b->burst_time; + do_div(burst_usec, NSEC_PER_USEC); seq_printf(sf, "nr_periods %d\n" "nr_throttled %d\n" - "throttled_usec %llu\n", + "throttled_usec %llu\n" + "nr_bursts %d\n" + "burst_usec %llu\n", cfs_b->nr_periods, cfs_b->nr_throttled, - throttled_usec); + throttled_usec, cfs_b->nr_burst, burst_usec); } #endif return 0; diff --git a/kernel/sched/core_sched.c b/kernel/sched/core_sched.c index 9a80e9a474c0..48ac72696012 100644 --- a/kernel/sched/core_sched.c +++ b/kernel/sched/core_sched.c @@ -11,7 +11,7 @@ struct sched_core_cookie { refcount_t refcnt; }; -unsigned long sched_core_alloc_cookie(void) +static unsigned long sched_core_alloc_cookie(void) { struct sched_core_cookie *ck = kmalloc(sizeof(*ck), GFP_KERNEL); if (!ck) @@ -23,7 +23,7 @@ unsigned long sched_core_alloc_cookie(void) return (unsigned long)ck; } -void sched_core_put_cookie(unsigned long cookie) +static void sched_core_put_cookie(unsigned long cookie) { struct sched_core_cookie *ptr = (void *)cookie; @@ -33,7 +33,7 @@ void sched_core_put_cookie(unsigned long cookie) } } -unsigned long sched_core_get_cookie(unsigned long cookie) +static unsigned long sched_core_get_cookie(unsigned long cookie) { struct sched_core_cookie *ptr = (void *)cookie; @@ -53,7 +53,8 @@ unsigned long sched_core_get_cookie(unsigned long cookie) * * Returns: the old cookie */ -unsigned long sched_core_update_cookie(struct task_struct *p, unsigned long cookie) +static unsigned long sched_core_update_cookie(struct task_struct *p, + unsigned long cookie) { unsigned long old_cookie; struct rq_flags rf; diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index e94314633b39..d2c072b0ef01 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1265,8 +1265,10 @@ static void update_curr_dl(struct rq *rq) return; } - schedstat_set(curr->se.statistics.exec_max, - max(curr->se.statistics.exec_max, delta_exec)); + schedstat_set(curr->stats.exec_max, + max(curr->stats.exec_max, delta_exec)); + + trace_sched_stat_runtime(curr, delta_exec, 0); curr->se.sum_exec_runtime += delta_exec; account_group_exec_runtime(curr, delta_exec); @@ -1472,6 +1474,82 @@ static inline bool __dl_less(struct rb_node *a, const struct rb_node *b) return dl_time_before(__node_2_dle(a)->deadline, __node_2_dle(b)->deadline); } +static inline struct sched_statistics * +__schedstats_from_dl_se(struct sched_dl_entity *dl_se) +{ + return &dl_task_of(dl_se)->stats; +} + +static inline void +update_stats_wait_start_dl(struct dl_rq *dl_rq, struct sched_dl_entity *dl_se) +{ + struct sched_statistics *stats; + + if (!schedstat_enabled()) + return; + + stats = __schedstats_from_dl_se(dl_se); + __update_stats_wait_start(rq_of_dl_rq(dl_rq), dl_task_of(dl_se), stats); +} + +static inline void +update_stats_wait_end_dl(struct dl_rq *dl_rq, struct sched_dl_entity *dl_se) +{ + struct sched_statistics *stats; + + if (!schedstat_enabled()) + return; + + stats = __schedstats_from_dl_se(dl_se); + __update_stats_wait_end(rq_of_dl_rq(dl_rq), dl_task_of(dl_se), stats); +} + +static inline void +update_stats_enqueue_sleeper_dl(struct dl_rq *dl_rq, struct sched_dl_entity *dl_se) +{ + struct sched_statistics *stats; + + if (!schedstat_enabled()) + return; + + stats = __schedstats_from_dl_se(dl_se); + __update_stats_enqueue_sleeper(rq_of_dl_rq(dl_rq), dl_task_of(dl_se), stats); +} + +static inline void +update_stats_enqueue_dl(struct dl_rq *dl_rq, struct sched_dl_entity *dl_se, + int flags) +{ + if (!schedstat_enabled()) + return; + + if (flags & ENQUEUE_WAKEUP) + update_stats_enqueue_sleeper_dl(dl_rq, dl_se); +} + +static inline void +update_stats_dequeue_dl(struct dl_rq *dl_rq, struct sched_dl_entity *dl_se, + int flags) +{ + struct task_struct *p = dl_task_of(dl_se); + + if (!schedstat_enabled()) + return; + + if ((flags & DEQUEUE_SLEEP)) { + unsigned int state; + + state = READ_ONCE(p->__state); + if (state & TASK_INTERRUPTIBLE) + __schedstat_set(p->stats.sleep_start, + rq_clock(rq_of_dl_rq(dl_rq))); + + if (state & TASK_UNINTERRUPTIBLE) + __schedstat_set(p->stats.block_start, + rq_clock(rq_of_dl_rq(dl_rq))); + } +} + static void __enqueue_dl_entity(struct sched_dl_entity *dl_se) { struct dl_rq *dl_rq = dl_rq_of_se(dl_se); @@ -1502,6 +1580,8 @@ enqueue_dl_entity(struct sched_dl_entity *dl_se, int flags) { BUG_ON(on_dl_rq(dl_se)); + update_stats_enqueue_dl(dl_rq_of_se(dl_se), dl_se, flags); + /* * If this is a wakeup or a new instance, the scheduling * parameters of the task might need updating. Otherwise, @@ -1598,6 +1678,9 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags) return; } + check_schedstat_required(); + update_stats_wait_start_dl(dl_rq_of_se(&p->dl), &p->dl); + enqueue_dl_entity(&p->dl, flags); if (!task_current(rq, p) && p->nr_cpus_allowed > 1) @@ -1606,6 +1689,7 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags) static void __dequeue_task_dl(struct rq *rq, struct task_struct *p, int flags) { + update_stats_dequeue_dl(&rq->dl, &p->dl, flags); dequeue_dl_entity(&p->dl); dequeue_pushable_dl_task(rq, p); } @@ -1825,7 +1909,12 @@ static void start_hrtick_dl(struct rq *rq, struct task_struct *p) static void set_next_task_dl(struct rq *rq, struct task_struct *p, bool first) { + struct sched_dl_entity *dl_se = &p->dl; + struct dl_rq *dl_rq = &rq->dl; + p->se.exec_start = rq_clock_task(rq); + if (on_dl_rq(&p->dl)) + update_stats_wait_end_dl(dl_rq, dl_se); /* You can't push away the running task */ dequeue_pushable_dl_task(rq, p); @@ -1882,6 +1971,12 @@ static struct task_struct *pick_next_task_dl(struct rq *rq) static void put_prev_task_dl(struct rq *rq, struct task_struct *p) { + struct sched_dl_entity *dl_se = &p->dl; + struct dl_rq *dl_rq = &rq->dl; + + if (on_dl_rq(&p->dl)) + update_stats_wait_start_dl(dl_rq, dl_se); + update_curr_dl(rq); update_dl_rq_load_avg(rq_clock_pelt(rq), rq, 1); diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 17a653b67006..7dcbaa31c5d9 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -311,6 +311,7 @@ static __init int sched_init_debug(void) debugfs_create_u32("latency_ns", 0644, debugfs_sched, &sysctl_sched_latency); debugfs_create_u32("min_granularity_ns", 0644, debugfs_sched, &sysctl_sched_min_granularity); + debugfs_create_u32("idle_min_granularity_ns", 0644, debugfs_sched, &sysctl_sched_idle_min_granularity); debugfs_create_u32("wakeup_granularity_ns", 0644, debugfs_sched, &sysctl_sched_wakeup_granularity); debugfs_create_u32("latency_warn_ms", 0644, debugfs_sched, &sysctl_resched_latency_warn_ms); @@ -448,9 +449,11 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group struct sched_entity *se = tg->se[cpu]; #define P(F) SEQ_printf(m, " .%-30s: %lld\n", #F, (long long)F) -#define P_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld\n", #F, (long long)schedstat_val(F)) +#define P_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld\n", \ + #F, (long long)schedstat_val(stats->F)) #define PN(F) SEQ_printf(m, " .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F)) -#define PN_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)schedstat_val(F))) +#define PN_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld.%06ld\n", \ + #F, SPLIT_NS((long long)schedstat_val(stats->F))) if (!se) return; @@ -460,16 +463,19 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group PN(se->sum_exec_runtime); if (schedstat_enabled()) { - PN_SCHEDSTAT(se->statistics.wait_start); - PN_SCHEDSTAT(se->statistics.sleep_start); - PN_SCHEDSTAT(se->statistics.block_start); - PN_SCHEDSTAT(se->statistics.sleep_max); - PN_SCHEDSTAT(se->statistics.block_max); - PN_SCHEDSTAT(se->statistics.exec_max); - PN_SCHEDSTAT(se->statistics.slice_max); - PN_SCHEDSTAT(se->statistics.wait_max); - PN_SCHEDSTAT(se->statistics.wait_sum); - P_SCHEDSTAT(se->statistics.wait_count); + struct sched_statistics *stats; + stats = __schedstats_from_se(se); + + PN_SCHEDSTAT(wait_start); + PN_SCHEDSTAT(sleep_start); + PN_SCHEDSTAT(block_start); + PN_SCHEDSTAT(sleep_max); + PN_SCHEDSTAT(block_max); + PN_SCHEDSTAT(exec_max); + PN_SCHEDSTAT(slice_max); + PN_SCHEDSTAT(wait_max); + PN_SCHEDSTAT(wait_sum); + P_SCHEDSTAT(wait_count); } P(se->load.weight); @@ -535,10 +541,11 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p) (long long)(p->nvcsw + p->nivcsw), p->prio); - SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld", - SPLIT_NS(schedstat_val_or_zero(p->se.statistics.wait_sum)), + SEQ_printf(m, "%9lld.%06ld %9lld.%06ld %9lld.%06ld %9lld.%06ld", + SPLIT_NS(schedstat_val_or_zero(p->stats.wait_sum)), SPLIT_NS(p->se.sum_exec_runtime), - SPLIT_NS(schedstat_val_or_zero(p->se.statistics.sum_sleep_runtime))); + SPLIT_NS(schedstat_val_or_zero(p->stats.sum_sleep_runtime)), + SPLIT_NS(schedstat_val_or_zero(p->stats.sum_block_runtime))); #ifdef CONFIG_NUMA_BALANCING SEQ_printf(m, " %d %d", task_node(p), task_numa_group_id(p)); @@ -614,6 +621,8 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) cfs_rq->nr_spread_over); SEQ_printf(m, " .%-30s: %d\n", "nr_running", cfs_rq->nr_running); SEQ_printf(m, " .%-30s: %d\n", "h_nr_running", cfs_rq->h_nr_running); + SEQ_printf(m, " .%-30s: %d\n", "idle_nr_running", + cfs_rq->idle_nr_running); SEQ_printf(m, " .%-30s: %d\n", "idle_h_nr_running", cfs_rq->idle_h_nr_running); SEQ_printf(m, " .%-30s: %ld\n", "load", cfs_rq->load.weight); @@ -810,6 +819,7 @@ static void sched_debug_header(struct seq_file *m) SEQ_printf(m, " .%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x)) PN(sysctl_sched_latency); PN(sysctl_sched_min_granularity); + PN(sysctl_sched_idle_min_granularity); PN(sysctl_sched_wakeup_granularity); P(sysctl_sched_child_runs_first); P(sysctl_sched_features); @@ -954,8 +964,8 @@ void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns, "---------------------------------------------------------" "----------\n"); -#define P_SCHEDSTAT(F) __PS(#F, schedstat_val(p->F)) -#define PN_SCHEDSTAT(F) __PSN(#F, schedstat_val(p->F)) +#define P_SCHEDSTAT(F) __PS(#F, schedstat_val(p->stats.F)) +#define PN_SCHEDSTAT(F) __PSN(#F, schedstat_val(p->stats.F)) PN(se.exec_start); PN(se.vruntime); @@ -968,33 +978,34 @@ void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns, if (schedstat_enabled()) { u64 avg_atom, avg_per_cpu; - PN_SCHEDSTAT(se.statistics.sum_sleep_runtime); - PN_SCHEDSTAT(se.statistics.wait_start); - PN_SCHEDSTAT(se.statistics.sleep_start); - PN_SCHEDSTAT(se.statistics.block_start); - PN_SCHEDSTAT(se.statistics.sleep_max); - PN_SCHEDSTAT(se.statistics.block_max); - PN_SCHEDSTAT(se.statistics.exec_max); - PN_SCHEDSTAT(se.statistics.slice_max); - PN_SCHEDSTAT(se.statistics.wait_max); - PN_SCHEDSTAT(se.statistics.wait_sum); - P_SCHEDSTAT(se.statistics.wait_count); - PN_SCHEDSTAT(se.statistics.iowait_sum); - P_SCHEDSTAT(se.statistics.iowait_count); - P_SCHEDSTAT(se.statistics.nr_migrations_cold); - P_SCHEDSTAT(se.statistics.nr_failed_migrations_affine); - P_SCHEDSTAT(se.statistics.nr_failed_migrations_running); - P_SCHEDSTAT(se.statistics.nr_failed_migrations_hot); - P_SCHEDSTAT(se.statistics.nr_forced_migrations); - P_SCHEDSTAT(se.statistics.nr_wakeups); - P_SCHEDSTAT(se.statistics.nr_wakeups_sync); - P_SCHEDSTAT(se.statistics.nr_wakeups_migrate); - P_SCHEDSTAT(se.statistics.nr_wakeups_local); - P_SCHEDSTAT(se.statistics.nr_wakeups_remote); - P_SCHEDSTAT(se.statistics.nr_wakeups_affine); - P_SCHEDSTAT(se.statistics.nr_wakeups_affine_attempts); - P_SCHEDSTAT(se.statistics.nr_wakeups_passive); - P_SCHEDSTAT(se.statistics.nr_wakeups_idle); + PN_SCHEDSTAT(sum_sleep_runtime); + PN_SCHEDSTAT(sum_block_runtime); + PN_SCHEDSTAT(wait_start); + PN_SCHEDSTAT(sleep_start); + PN_SCHEDSTAT(block_start); + PN_SCHEDSTAT(sleep_max); + PN_SCHEDSTAT(block_max); + PN_SCHEDSTAT(exec_max); + PN_SCHEDSTAT(slice_max); + PN_SCHEDSTAT(wait_max); + PN_SCHEDSTAT(wait_sum); + P_SCHEDSTAT(wait_count); + PN_SCHEDSTAT(iowait_sum); + P_SCHEDSTAT(iowait_count); + P_SCHEDSTAT(nr_migrations_cold); + P_SCHEDSTAT(nr_failed_migrations_affine); + P_SCHEDSTAT(nr_failed_migrations_running); + P_SCHEDSTAT(nr_failed_migrations_hot); + P_SCHEDSTAT(nr_forced_migrations); + P_SCHEDSTAT(nr_wakeups); + P_SCHEDSTAT(nr_wakeups_sync); + P_SCHEDSTAT(nr_wakeups_migrate); + P_SCHEDSTAT(nr_wakeups_local); + P_SCHEDSTAT(nr_wakeups_remote); + P_SCHEDSTAT(nr_wakeups_affine); + P_SCHEDSTAT(nr_wakeups_affine_attempts); + P_SCHEDSTAT(nr_wakeups_passive); + P_SCHEDSTAT(nr_wakeups_idle); avg_atom = p->se.sum_exec_runtime; if (nr_switches) @@ -1060,7 +1071,7 @@ void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns, void proc_sched_set_task(struct task_struct *p) { #ifdef CONFIG_SCHEDSTATS - memset(&p->se.statistics, 0, sizeof(p->se.statistics)); + memset(&p->stats, 0, sizeof(p->stats)); #endif } diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index f6a05d9b5443..13950beb01a2 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -60,6 +60,14 @@ unsigned int sysctl_sched_min_granularity = 750000ULL; static unsigned int normalized_sysctl_sched_min_granularity = 750000ULL; /* + * Minimal preemption granularity for CPU-bound SCHED_IDLE tasks. + * Applies only when SCHED_IDLE tasks compete with normal tasks. + * + * (default: 0.75 msec) + */ +unsigned int sysctl_sched_idle_min_granularity = 750000ULL; + +/* * This value is kept at sysctl_sched_latency/sysctl_sched_min_granularity */ static unsigned int sched_nr_latency = 8; @@ -665,6 +673,8 @@ static u64 __sched_period(unsigned long nr_running) return sysctl_sched_latency; } +static bool sched_idle_cfs_rq(struct cfs_rq *cfs_rq); + /* * We calculate the wall-time slice from the period by taking a part * proportional to the weight. @@ -674,6 +684,8 @@ static u64 __sched_period(unsigned long nr_running) static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se) { unsigned int nr_running = cfs_rq->nr_running; + struct sched_entity *init_se = se; + unsigned int min_gran; u64 slice; if (sched_feat(ALT_PERIOD)) @@ -684,12 +696,13 @@ static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se) for_each_sched_entity(se) { struct load_weight *load; struct load_weight lw; + struct cfs_rq *qcfs_rq; - cfs_rq = cfs_rq_of(se); - load = &cfs_rq->load; + qcfs_rq = cfs_rq_of(se); + load = &qcfs_rq->load; if (unlikely(!se->on_rq)) { - lw = cfs_rq->load; + lw = qcfs_rq->load; update_load_add(&lw, se->load.weight); load = &lw; @@ -697,8 +710,14 @@ static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se) slice = __calc_delta(slice, se->load.weight, load); } - if (sched_feat(BASE_SLICE)) - slice = max(slice, (u64)sysctl_sched_min_granularity); + if (sched_feat(BASE_SLICE)) { + if (se_is_idle(init_se) && !sched_idle_cfs_rq(cfs_rq)) + min_gran = sysctl_sched_idle_min_granularity; + else + min_gran = sysctl_sched_min_granularity; + + slice = max_t(u64, slice, min_gran); + } return slice; } @@ -837,8 +856,13 @@ static void update_curr(struct cfs_rq *cfs_rq) curr->exec_start = now; - schedstat_set(curr->statistics.exec_max, - max(delta_exec, curr->statistics.exec_max)); + if (schedstat_enabled()) { + struct sched_statistics *stats; + + stats = __schedstats_from_se(curr); + __schedstat_set(stats->exec_max, + max(delta_exec, stats->exec_max)); + } curr->sum_exec_runtime += delta_exec; schedstat_add(cfs_rq->exec_clock, delta_exec); @@ -863,137 +887,70 @@ static void update_curr_fair(struct rq *rq) } static inline void -update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se) +update_stats_wait_start_fair(struct cfs_rq *cfs_rq, struct sched_entity *se) { - u64 wait_start, prev_wait_start; + struct sched_statistics *stats; + struct task_struct *p = NULL; if (!schedstat_enabled()) return; - wait_start = rq_clock(rq_of(cfs_rq)); - prev_wait_start = schedstat_val(se->statistics.wait_start); + stats = __schedstats_from_se(se); - if (entity_is_task(se) && task_on_rq_migrating(task_of(se)) && - likely(wait_start > prev_wait_start)) - wait_start -= prev_wait_start; + if (entity_is_task(se)) + p = task_of(se); - __schedstat_set(se->statistics.wait_start, wait_start); + __update_stats_wait_start(rq_of(cfs_rq), p, stats); } static inline void -update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se) +update_stats_wait_end_fair(struct cfs_rq *cfs_rq, struct sched_entity *se) { - struct task_struct *p; - u64 delta; + struct sched_statistics *stats; + struct task_struct *p = NULL; if (!schedstat_enabled()) return; + stats = __schedstats_from_se(se); + /* * When the sched_schedstat changes from 0 to 1, some sched se * maybe already in the runqueue, the se->statistics.wait_start * will be 0.So it will let the delta wrong. We need to avoid this * scenario. */ - if (unlikely(!schedstat_val(se->statistics.wait_start))) + if (unlikely(!schedstat_val(stats->wait_start))) return; - delta = rq_clock(rq_of(cfs_rq)) - schedstat_val(se->statistics.wait_start); - - if (entity_is_task(se)) { + if (entity_is_task(se)) p = task_of(se); - if (task_on_rq_migrating(p)) { - /* - * Preserve migrating task's wait time so wait_start - * time stamp can be adjusted to accumulate wait time - * prior to migration. - */ - __schedstat_set(se->statistics.wait_start, delta); - return; - } - trace_sched_stat_wait(p, delta); - } - __schedstat_set(se->statistics.wait_max, - max(schedstat_val(se->statistics.wait_max), delta)); - __schedstat_inc(se->statistics.wait_count); - __schedstat_add(se->statistics.wait_sum, delta); - __schedstat_set(se->statistics.wait_start, 0); + __update_stats_wait_end(rq_of(cfs_rq), p, stats); } static inline void -update_stats_enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) +update_stats_enqueue_sleeper_fair(struct cfs_rq *cfs_rq, struct sched_entity *se) { + struct sched_statistics *stats; struct task_struct *tsk = NULL; - u64 sleep_start, block_start; if (!schedstat_enabled()) return; - sleep_start = schedstat_val(se->statistics.sleep_start); - block_start = schedstat_val(se->statistics.block_start); + stats = __schedstats_from_se(se); if (entity_is_task(se)) tsk = task_of(se); - if (sleep_start) { - u64 delta = rq_clock(rq_of(cfs_rq)) - sleep_start; - - if ((s64)delta < 0) - delta = 0; - - if (unlikely(delta > schedstat_val(se->statistics.sleep_max))) - __schedstat_set(se->statistics.sleep_max, delta); - - __schedstat_set(se->statistics.sleep_start, 0); - __schedstat_add(se->statistics.sum_sleep_runtime, delta); - - if (tsk) { - account_scheduler_latency(tsk, delta >> 10, 1); - trace_sched_stat_sleep(tsk, delta); - } - } - if (block_start) { - u64 delta = rq_clock(rq_of(cfs_rq)) - block_start; - - if ((s64)delta < 0) - delta = 0; - - if (unlikely(delta > schedstat_val(se->statistics.block_max))) - __schedstat_set(se->statistics.block_max, delta); - - __schedstat_set(se->statistics.block_start, 0); - __schedstat_add(se->statistics.sum_sleep_runtime, delta); - - if (tsk) { - if (tsk->in_iowait) { - __schedstat_add(se->statistics.iowait_sum, delta); - __schedstat_inc(se->statistics.iowait_count); - trace_sched_stat_iowait(tsk, delta); - } - - trace_sched_stat_blocked(tsk, delta); - - /* - * Blocking time is in units of nanosecs, so shift by - * 20 to get a milliseconds-range estimation of the - * amount of time that the task spent sleeping: - */ - if (unlikely(prof_on == SLEEP_PROFILING)) { - profile_hits(SLEEP_PROFILING, - (void *)get_wchan(tsk), - delta >> 20); - } - account_scheduler_latency(tsk, delta >> 10, 0); - } - } + __update_stats_enqueue_sleeper(rq_of(cfs_rq), tsk, stats); } /* * Task is being enqueued - update stats: */ static inline void -update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) +update_stats_enqueue_fair(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) { if (!schedstat_enabled()) return; @@ -1003,14 +960,14 @@ update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) * a dequeue/enqueue event is a NOP) */ if (se != cfs_rq->curr) - update_stats_wait_start(cfs_rq, se); + update_stats_wait_start_fair(cfs_rq, se); if (flags & ENQUEUE_WAKEUP) - update_stats_enqueue_sleeper(cfs_rq, se); + update_stats_enqueue_sleeper_fair(cfs_rq, se); } static inline void -update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) +update_stats_dequeue_fair(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) { if (!schedstat_enabled()) @@ -1021,7 +978,7 @@ update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) * waiting task: */ if (se != cfs_rq->curr) - update_stats_wait_end(cfs_rq, se); + update_stats_wait_end_fair(cfs_rq, se); if ((flags & DEQUEUE_SLEEP) && entity_is_task(se)) { struct task_struct *tsk = task_of(se); @@ -1030,10 +987,10 @@ update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) /* XXX racy against TTWU */ state = READ_ONCE(tsk->__state); if (state & TASK_INTERRUPTIBLE) - __schedstat_set(se->statistics.sleep_start, + __schedstat_set(tsk->stats.sleep_start, rq_clock(rq_of(cfs_rq))); if (state & TASK_UNINTERRUPTIBLE) - __schedstat_set(se->statistics.block_start, + __schedstat_set(tsk->stats.block_start, rq_clock(rq_of(cfs_rq))); } } @@ -1081,11 +1038,12 @@ struct numa_group { unsigned long total_faults; unsigned long max_faults_cpu; /* + * faults[] array is split into two regions: faults_mem and faults_cpu. + * * Faults_cpu is used to decide whether memory should move * towards the CPU. As a consequence, these stats are weighted * more by CPU use than by memory faults. */ - unsigned long *faults_cpu; unsigned long faults[]; }; @@ -1259,8 +1217,8 @@ static inline unsigned long group_faults(struct task_struct *p, int nid) static inline unsigned long group_faults_cpu(struct numa_group *group, int nid) { - return group->faults_cpu[task_faults_idx(NUMA_MEM, nid, 0)] + - group->faults_cpu[task_faults_idx(NUMA_MEM, nid, 1)]; + return group->faults[task_faults_idx(NUMA_CPU, nid, 0)] + + group->faults[task_faults_idx(NUMA_CPU, nid, 1)]; } static inline unsigned long group_faults_priv(struct numa_group *ng) @@ -2116,7 +2074,7 @@ static void numa_migrate_preferred(struct task_struct *p) } /* - * Find out how many nodes on the workload is actively running on. Do this by + * Find out how many nodes the workload is actively running on. Do this by * tracking the nodes from which NUMA hinting faults are triggered. This can * be different from the set of nodes where the workload's memory is currently * located. @@ -2170,7 +2128,7 @@ static void update_task_scan_period(struct task_struct *p, /* * If there were no record hinting faults then either the task is - * completely idle or all activity is areas that are not of interest + * completely idle or all activity is in areas that are not of interest * to automatic numa balancing. Related to that, if there were failed * migration then it implies we are migrating too quickly or the local * node is overloaded. In either case, scan slower @@ -2427,7 +2385,7 @@ static void task_numa_placement(struct task_struct *p) * is at the beginning of the numa_faults array. */ ng->faults[mem_idx] += diff; - ng->faults_cpu[mem_idx] += f_diff; + ng->faults[cpu_idx] += f_diff; ng->total_faults += diff; group_faults += ng->faults[mem_idx]; } @@ -2481,7 +2439,8 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags, if (unlikely(!deref_curr_numa_group(p))) { unsigned int size = sizeof(struct numa_group) + - 4*nr_node_ids*sizeof(unsigned long); + NR_NUMA_HINT_FAULT_STATS * + nr_node_ids * sizeof(unsigned long); grp = kzalloc(size, GFP_KERNEL | __GFP_NOWARN); if (!grp) @@ -2492,9 +2451,6 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags, grp->max_faults_cpu = 0; spin_lock_init(&grp->lock); grp->gid = p->pid; - /* Second half of the array tracks nids where faults happen */ - grp->faults_cpu = grp->faults + NR_NUMA_HINT_FAULT_TYPES * - nr_node_ids; for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++) grp->faults[i] = p->numa_faults[i]; @@ -2995,6 +2951,8 @@ account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se) } #endif cfs_rq->nr_running++; + if (se_is_idle(se)) + cfs_rq->idle_nr_running++; } static void @@ -3008,6 +2966,8 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se) } #endif cfs_rq->nr_running--; + if (se_is_idle(se)) + cfs_rq->idle_nr_running--; } /* @@ -4207,7 +4167,12 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) /* sleeps up to a single latency don't count. */ if (!initial) { - unsigned long thresh = sysctl_sched_latency; + unsigned long thresh; + + if (se_is_idle(se)) + thresh = sysctl_sched_min_granularity; + else + thresh = sysctl_sched_latency; /* * Halve their sleep time's effect, to allow @@ -4225,26 +4190,6 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) static void check_enqueue_throttle(struct cfs_rq *cfs_rq); -static inline void check_schedstat_required(void) -{ -#ifdef CONFIG_SCHEDSTATS - if (schedstat_enabled()) - return; - - /* Force schedstat enabled if a dependent tracepoint is active */ - if (trace_sched_stat_wait_enabled() || - trace_sched_stat_sleep_enabled() || - trace_sched_stat_iowait_enabled() || - trace_sched_stat_blocked_enabled() || - trace_sched_stat_runtime_enabled()) { - printk_deferred_once("Scheduler tracepoints stat_sleep, stat_iowait, " - "stat_blocked and stat_runtime require the " - "kernel parameter schedstats=enable or " - "kernel.sched_schedstats=1\n"); - } -#endif -} - static inline bool cfs_bandwidth_used(void); /* @@ -4318,7 +4263,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) place_entity(cfs_rq, se, 0); check_schedstat_required(); - update_stats_enqueue(cfs_rq, se, flags); + update_stats_enqueue_fair(cfs_rq, se, flags); check_spread(cfs_rq, se); if (!curr) __enqueue_entity(cfs_rq, se); @@ -4402,7 +4347,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) update_load_avg(cfs_rq, se, UPDATE_TG); se_update_runnable(se); - update_stats_dequeue(cfs_rq, se, flags); + update_stats_dequeue_fair(cfs_rq, se, flags); clear_buddies(cfs_rq, se); @@ -4487,7 +4432,7 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) * a CPU. So account for the time it spent waiting on the * runqueue. */ - update_stats_wait_end(cfs_rq, se); + update_stats_wait_end_fair(cfs_rq, se); __dequeue_entity(cfs_rq, se); update_load_avg(cfs_rq, se, UPDATE_TG); } @@ -4502,9 +4447,12 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) */ if (schedstat_enabled() && rq_of(cfs_rq)->cfs.load.weight >= 2*se->load.weight) { - schedstat_set(se->statistics.slice_max, - max((u64)schedstat_val(se->statistics.slice_max), - se->sum_exec_runtime - se->prev_sum_exec_runtime)); + struct sched_statistics *stats; + + stats = __schedstats_from_se(se); + __schedstat_set(stats->slice_max, + max((u64)stats->slice_max, + se->sum_exec_runtime - se->prev_sum_exec_runtime)); } se->prev_sum_exec_runtime = se->sum_exec_runtime; @@ -4586,7 +4534,7 @@ static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev) check_spread(cfs_rq, prev); if (prev->on_rq) { - update_stats_wait_start(cfs_rq, prev); + update_stats_wait_start_fair(cfs_rq, prev); /* Put 'current' back into the tree. */ __enqueue_entity(cfs_rq, prev); /* in !on_rq case, update occurred at dequeue */ @@ -4687,11 +4635,20 @@ static inline u64 sched_cfs_bandwidth_slice(void) */ void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b) { + s64 runtime; + if (unlikely(cfs_b->quota == RUNTIME_INF)) return; cfs_b->runtime += cfs_b->quota; + runtime = cfs_b->runtime_snap - cfs_b->runtime; + if (runtime > 0) { + cfs_b->burst_time += runtime; + cfs_b->nr_burst++; + } + cfs_b->runtime = min(cfs_b->runtime, cfs_b->quota + cfs_b->burst); + cfs_b->runtime_snap = cfs_b->runtime; } static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg) @@ -5577,6 +5534,17 @@ static int sched_idle_rq(struct rq *rq) rq->nr_running); } +/* + * Returns true if cfs_rq only has SCHED_IDLE entities enqueued. Note the use + * of idle_nr_running, which does not consider idle descendants of normal + * entities. + */ +static bool sched_idle_cfs_rq(struct cfs_rq *cfs_rq) +{ + return cfs_rq->nr_running && + cfs_rq->nr_running == cfs_rq->idle_nr_running; +} + #ifdef CONFIG_SMP static int sched_idle_cpu(int cpu) { @@ -5787,6 +5755,7 @@ static struct { cpumask_var_t idle_cpus_mask; atomic_t nr_cpus; int has_blocked; /* Idle CPUS has blocked load */ + int needs_update; /* Newly idle CPUs need their next_balance collated */ unsigned long next_balance; /* in jiffy units */ unsigned long next_blocked; /* Next update of blocked load in jiffies */ } nohz ____cacheline_aligned; @@ -5997,12 +5966,12 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, if (sched_feat(WA_WEIGHT) && target == nr_cpumask_bits) target = wake_affine_weight(sd, p, this_cpu, prev_cpu, sync); - schedstat_inc(p->se.statistics.nr_wakeups_affine_attempts); + schedstat_inc(p->stats.nr_wakeups_affine_attempts); if (target == nr_cpumask_bits) return prev_cpu; schedstat_inc(sd->ttwu_move_affine); - schedstat_inc(p->se.statistics.nr_wakeups_affine); + schedstat_inc(p->stats.nr_wakeups_affine); return target; } @@ -6443,11 +6412,6 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target) (available_idle_cpu(recent_used_cpu) || sched_idle_cpu(recent_used_cpu)) && cpumask_test_cpu(p->recent_used_cpu, p->cpus_ptr) && asym_fits_capacity(task_util, recent_used_cpu)) { - /* - * Replace recent_used_cpu with prev as it is a potential - * candidate for the next wake: - */ - p->recent_used_cpu = prev; return recent_used_cpu; } @@ -7806,7 +7770,7 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env) if (!cpumask_test_cpu(env->dst_cpu, p->cpus_ptr)) { int cpu; - schedstat_inc(p->se.statistics.nr_failed_migrations_affine); + schedstat_inc(p->stats.nr_failed_migrations_affine); env->flags |= LBF_SOME_PINNED; @@ -7840,7 +7804,7 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env) env->flags &= ~LBF_ALL_PINNED; if (task_running(env->src_rq, p)) { - schedstat_inc(p->se.statistics.nr_failed_migrations_running); + schedstat_inc(p->stats.nr_failed_migrations_running); return 0; } @@ -7862,12 +7826,12 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env) env->sd->nr_balance_failed > env->sd->cache_nice_tries) { if (tsk_cache_hot == 1) { schedstat_inc(env->sd->lb_hot_gained[env->idle]); - schedstat_inc(p->se.statistics.nr_forced_migrations); + schedstat_inc(p->stats.nr_forced_migrations); } return 1; } - schedstat_inc(p->se.statistics.nr_failed_migrations_hot); + schedstat_inc(p->stats.nr_failed_migrations_hot); return 0; } @@ -8602,6 +8566,99 @@ group_type group_classify(unsigned int imbalance_pct, } /** + * asym_smt_can_pull_tasks - Check whether the load balancing CPU can pull tasks + * @dst_cpu: Destination CPU of the load balancing + * @sds: Load-balancing data with statistics of the local group + * @sgs: Load-balancing statistics of the candidate busiest group + * @sg: The candidate busiest group + * + * Check the state of the SMT siblings of both @sds::local and @sg and decide + * if @dst_cpu can pull tasks. + * + * If @dst_cpu does not have SMT siblings, it can pull tasks if two or more of + * the SMT siblings of @sg are busy. If only one CPU in @sg is busy, pull tasks + * only if @dst_cpu has higher priority. + * + * If both @dst_cpu and @sg have SMT siblings, and @sg has exactly one more + * busy CPU than @sds::local, let @dst_cpu pull tasks if it has higher priority. + * Bigger imbalances in the number of busy CPUs will be dealt with in + * update_sd_pick_busiest(). + * + * If @sg does not have SMT siblings, only pull tasks if all of the SMT siblings + * of @dst_cpu are idle and @sg has lower priority. + */ +static bool asym_smt_can_pull_tasks(int dst_cpu, struct sd_lb_stats *sds, + struct sg_lb_stats *sgs, + struct sched_group *sg) +{ +#ifdef CONFIG_SCHED_SMT + bool local_is_smt, sg_is_smt; + int sg_busy_cpus; + + local_is_smt = sds->local->flags & SD_SHARE_CPUCAPACITY; + sg_is_smt = sg->flags & SD_SHARE_CPUCAPACITY; + + sg_busy_cpus = sgs->group_weight - sgs->idle_cpus; + + if (!local_is_smt) { + /* + * If we are here, @dst_cpu is idle and does not have SMT + * siblings. Pull tasks if candidate group has two or more + * busy CPUs. + */ + if (sg_busy_cpus >= 2) /* implies sg_is_smt */ + return true; + + /* + * @dst_cpu does not have SMT siblings. @sg may have SMT + * siblings and only one is busy. In such case, @dst_cpu + * can help if it has higher priority and is idle (i.e., + * it has no running tasks). + */ + return sched_asym_prefer(dst_cpu, sg->asym_prefer_cpu); + } + + /* @dst_cpu has SMT siblings. */ + + if (sg_is_smt) { + int local_busy_cpus = sds->local->group_weight - + sds->local_stat.idle_cpus; + int busy_cpus_delta = sg_busy_cpus - local_busy_cpus; + + if (busy_cpus_delta == 1) + return sched_asym_prefer(dst_cpu, sg->asym_prefer_cpu); + + return false; + } + + /* + * @sg does not have SMT siblings. Ensure that @sds::local does not end + * up with more than one busy SMT sibling and only pull tasks if there + * are not busy CPUs (i.e., no CPU has running tasks). + */ + if (!sds->local_stat.sum_nr_running) + return sched_asym_prefer(dst_cpu, sg->asym_prefer_cpu); + + return false; +#else + /* Always return false so that callers deal with non-SMT cases. */ + return false; +#endif +} + +static inline bool +sched_asym(struct lb_env *env, struct sd_lb_stats *sds, struct sg_lb_stats *sgs, + struct sched_group *group) +{ + /* Only do SMT checks if either local or candidate have SMT siblings */ + if ((sds->local->flags & SD_SHARE_CPUCAPACITY) || + (group->flags & SD_SHARE_CPUCAPACITY)) + return asym_smt_can_pull_tasks(env->dst_cpu, sds, sgs, group); + + return sched_asym_prefer(env->dst_cpu, group->asym_prefer_cpu); +} + +/** * update_sg_lb_stats - Update sched_group's statistics for load balancing. * @env: The load balancing environment. * @group: sched_group whose statistics are to be updated. @@ -8609,6 +8666,7 @@ group_type group_classify(unsigned int imbalance_pct, * @sg_status: Holds flag indicating the status of the sched_group */ static inline void update_sg_lb_stats(struct lb_env *env, + struct sd_lb_stats *sds, struct sched_group *group, struct sg_lb_stats *sgs, int *sg_status) @@ -8617,7 +8675,7 @@ static inline void update_sg_lb_stats(struct lb_env *env, memset(sgs, 0, sizeof(*sgs)); - local_group = cpumask_test_cpu(env->dst_cpu, sched_group_span(group)); + local_group = group == sds->local; for_each_cpu_and(i, sched_group_span(group), env->cpus) { struct rq *rq = cpu_rq(i); @@ -8660,18 +8718,17 @@ static inline void update_sg_lb_stats(struct lb_env *env, } } - /* Check if dst CPU is idle and preferred to this group */ - if (env->sd->flags & SD_ASYM_PACKING && - env->idle != CPU_NOT_IDLE && - sgs->sum_h_nr_running && - sched_asym_prefer(env->dst_cpu, group->asym_prefer_cpu)) { - sgs->group_asym_packing = 1; - } - sgs->group_capacity = group->sgc->capacity; sgs->group_weight = group->group_weight; + /* Check if dst CPU is idle and preferred to this group */ + if (!local_group && env->sd->flags & SD_ASYM_PACKING && + env->idle != CPU_NOT_IDLE && sgs->sum_h_nr_running && + sched_asym(env, sds, sgs, group)) { + sgs->group_asym_packing = 1; + } + sgs->group_type = group_classify(env->sd->imbalance_pct, group, sgs); /* Computing avg_load makes sense only when group is overloaded */ @@ -9180,7 +9237,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd update_group_capacity(env->sd, env->dst_cpu); } - update_sg_lb_stats(env, sg, sgs, &sg_status); + update_sg_lb_stats(env, sds, sg, sgs, &sg_status); if (local_group) goto next_group; @@ -9603,6 +9660,12 @@ static struct rq *find_busiest_queue(struct lb_env *env, nr_running == 1) continue; + /* Make sure we only pull tasks from a CPU of lower priority */ + if ((env->sd->flags & SD_ASYM_PACKING) && + sched_asym_prefer(i, env->dst_cpu) && + nr_running == 1) + continue; + switch (env->migration_type) { case migrate_load: /* @@ -10176,6 +10239,30 @@ void update_max_interval(void) max_load_balance_interval = HZ*num_online_cpus()/10; } +static inline bool update_newidle_cost(struct sched_domain *sd, u64 cost) +{ + if (cost > sd->max_newidle_lb_cost) { + /* + * Track max cost of a domain to make sure to not delay the + * next wakeup on the CPU. + */ + sd->max_newidle_lb_cost = cost; + sd->last_decay_max_lb_cost = jiffies; + } else if (time_after(jiffies, sd->last_decay_max_lb_cost + HZ)) { + /* + * Decay the newidle max times by ~1% per second to ensure that + * it is not outdated and the current max cost is actually + * shorter. + */ + sd->max_newidle_lb_cost = (sd->max_newidle_lb_cost * 253) / 256; + sd->last_decay_max_lb_cost = jiffies; + + return true; + } + + return false; +} + /* * It checks each scheduling domain to see if it is due to be balanced, * and initiates a balancing operation if so. @@ -10199,14 +10286,9 @@ static void rebalance_domains(struct rq *rq, enum cpu_idle_type idle) for_each_domain(cpu, sd) { /* * Decay the newidle max times here because this is a regular - * visit to all the domains. Decay ~1% per second. + * visit to all the domains. */ - if (time_after(jiffies, sd->next_decay_max_lb_cost)) { - sd->max_newidle_lb_cost = - (sd->max_newidle_lb_cost * 253) / 256; - sd->next_decay_max_lb_cost = jiffies + HZ; - need_decay = 1; - } + need_decay = update_newidle_cost(sd, 0); max_cost += sd->max_newidle_lb_cost; /* @@ -10375,7 +10457,7 @@ static void nohz_balancer_kick(struct rq *rq) goto out; if (rq->nr_running >= 2) { - flags = NOHZ_KICK_MASK; + flags = NOHZ_STATS_KICK | NOHZ_BALANCE_KICK; goto out; } @@ -10389,7 +10471,7 @@ static void nohz_balancer_kick(struct rq *rq) * on. */ if (rq->cfs.h_nr_running >= 1 && check_cpu_capacity(rq, sd)) { - flags = NOHZ_KICK_MASK; + flags = NOHZ_STATS_KICK | NOHZ_BALANCE_KICK; goto unlock; } } @@ -10403,7 +10485,7 @@ static void nohz_balancer_kick(struct rq *rq) */ for_each_cpu_and(i, sched_domain_span(sd), nohz.idle_cpus_mask) { if (sched_asym_prefer(i, cpu)) { - flags = NOHZ_KICK_MASK; + flags = NOHZ_STATS_KICK | NOHZ_BALANCE_KICK; goto unlock; } } @@ -10416,7 +10498,7 @@ static void nohz_balancer_kick(struct rq *rq) * to run the misfit task on. */ if (check_misfit_status(rq, sd)) { - flags = NOHZ_KICK_MASK; + flags = NOHZ_STATS_KICK | NOHZ_BALANCE_KICK; goto unlock; } @@ -10443,13 +10525,16 @@ static void nohz_balancer_kick(struct rq *rq) */ nr_busy = atomic_read(&sds->nr_busy_cpus); if (nr_busy > 1) { - flags = NOHZ_KICK_MASK; + flags = NOHZ_STATS_KICK | NOHZ_BALANCE_KICK; goto unlock; } } unlock: rcu_read_unlock(); out: + if (READ_ONCE(nohz.needs_update)) + flags |= NOHZ_NEXT_KICK; + if (flags) kick_ilb(flags); } @@ -10546,12 +10631,13 @@ void nohz_balance_enter_idle(int cpu) /* * Ensures that if nohz_idle_balance() fails to observe our * @idle_cpus_mask store, it must observe the @has_blocked - * store. + * and @needs_update stores. */ smp_mb__after_atomic(); set_cpu_sd_state_idle(cpu); + WRITE_ONCE(nohz.needs_update, 1); out: /* * Each time a cpu enter idle, we assume that it has blocked load and @@ -10600,12 +10686,17 @@ static void _nohz_idle_balance(struct rq *this_rq, unsigned int flags, /* * We assume there will be no idle load after this update and clear * the has_blocked flag. If a cpu enters idle in the mean time, it will - * set the has_blocked flag and trig another update of idle load. + * set the has_blocked flag and trigger another update of idle load. * Because a cpu that becomes idle, is added to idle_cpus_mask before * setting the flag, we are sure to not clear the state and not * check the load of an idle cpu. + * + * Same applies to idle_cpus_mask vs needs_update. */ - WRITE_ONCE(nohz.has_blocked, 0); + if (flags & NOHZ_STATS_KICK) + WRITE_ONCE(nohz.has_blocked, 0); + if (flags & NOHZ_NEXT_KICK) + WRITE_ONCE(nohz.needs_update, 0); /* * Ensures that if we miss the CPU, we must see the has_blocked @@ -10627,13 +10718,17 @@ static void _nohz_idle_balance(struct rq *this_rq, unsigned int flags, * balancing owner will pick it up. */ if (need_resched()) { - has_blocked_load = true; + if (flags & NOHZ_STATS_KICK) + has_blocked_load = true; + if (flags & NOHZ_NEXT_KICK) + WRITE_ONCE(nohz.needs_update, 1); goto abort; } rq = cpu_rq(balance_cpu); - has_blocked_load |= update_nohz_stats(rq); + if (flags & NOHZ_STATS_KICK) + has_blocked_load |= update_nohz_stats(rq); /* * If time for next balance is due, @@ -10664,8 +10759,9 @@ static void _nohz_idle_balance(struct rq *this_rq, unsigned int flags, if (likely(update_next_balance)) nohz.next_balance = next_balance; - WRITE_ONCE(nohz.next_blocked, - now + msecs_to_jiffies(LOAD_AVG_PERIOD)); + if (flags & NOHZ_STATS_KICK) + WRITE_ONCE(nohz.next_blocked, + now + msecs_to_jiffies(LOAD_AVG_PERIOD)); abort: /* There is still blocked load, enable periodic update */ @@ -10763,9 +10859,9 @@ static int newidle_balance(struct rq *this_rq, struct rq_flags *rf) { unsigned long next_balance = jiffies + HZ; int this_cpu = this_rq->cpu; + u64 t0, t1, curr_cost = 0; struct sched_domain *sd; int pulled_task = 0; - u64 curr_cost = 0; update_misfit_status(NULL, this_rq); @@ -10796,47 +10892,49 @@ static int newidle_balance(struct rq *this_rq, struct rq_flags *rf) */ rq_unpin_lock(this_rq, rf); - if (this_rq->avg_idle < sysctl_sched_migration_cost || - !READ_ONCE(this_rq->rd->overload)) { + rcu_read_lock(); + sd = rcu_dereference_check_sched_domain(this_rq->sd); + + if (!READ_ONCE(this_rq->rd->overload) || + (sd && this_rq->avg_idle < sd->max_newidle_lb_cost)) { - rcu_read_lock(); - sd = rcu_dereference_check_sched_domain(this_rq->sd); if (sd) update_next_balance(sd, &next_balance); rcu_read_unlock(); goto out; } + rcu_read_unlock(); raw_spin_rq_unlock(this_rq); + t0 = sched_clock_cpu(this_cpu); update_blocked_averages(this_cpu); + rcu_read_lock(); for_each_domain(this_cpu, sd) { int continue_balancing = 1; - u64 t0, domain_cost; + u64 domain_cost; - if (this_rq->avg_idle < curr_cost + sd->max_newidle_lb_cost) { - update_next_balance(sd, &next_balance); + update_next_balance(sd, &next_balance); + + if (this_rq->avg_idle < curr_cost + sd->max_newidle_lb_cost) break; - } if (sd->flags & SD_BALANCE_NEWIDLE) { - t0 = sched_clock_cpu(this_cpu); pulled_task = load_balance(this_cpu, this_rq, sd, CPU_NEWLY_IDLE, &continue_balancing); - domain_cost = sched_clock_cpu(this_cpu) - t0; - if (domain_cost > sd->max_newidle_lb_cost) - sd->max_newidle_lb_cost = domain_cost; + t1 = sched_clock_cpu(this_cpu); + domain_cost = t1 - t0; + update_newidle_cost(sd, domain_cost); curr_cost += domain_cost; + t0 = t1; } - update_next_balance(sd, &next_balance); - /* * Stop searching for tasks to pull if there are * now runnable tasks on this rq. @@ -11394,7 +11492,7 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) if (!cfs_rq) goto err; - se = kzalloc_node(sizeof(struct sched_entity), + se = kzalloc_node(sizeof(struct sched_entity_stats), GFP_KERNEL, cpu_to_node(i)); if (!se) goto err_free_rq; @@ -11560,7 +11658,7 @@ int sched_group_set_idle(struct task_group *tg, long idle) for_each_possible_cpu(i) { struct rq *rq = cpu_rq(i); struct sched_entity *se = tg->se[i]; - struct cfs_rq *grp_cfs_rq = tg->cfs_rq[i]; + struct cfs_rq *parent_cfs_rq, *grp_cfs_rq = tg->cfs_rq[i]; bool was_idle = cfs_rq_is_idle(grp_cfs_rq); long idle_task_delta; struct rq_flags rf; @@ -11571,6 +11669,14 @@ int sched_group_set_idle(struct task_group *tg, long idle) if (WARN_ON_ONCE(was_idle == cfs_rq_is_idle(grp_cfs_rq))) goto next_cpu; + if (se->on_rq) { + parent_cfs_rq = cfs_rq_of(se); + if (cfs_rq_is_idle(grp_cfs_rq)) + parent_cfs_rq->idle_nr_running++; + else + parent_cfs_rq->idle_nr_running--; + } + idle_task_delta = grp_cfs_rq->h_nr_running - grp_cfs_rq->idle_h_nr_running; if (!cfs_rq_is_idle(grp_cfs_rq)) diff --git a/kernel/sched/features.h b/kernel/sched/features.h index 7f8dace0964c..1cf435bbcd9c 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -46,11 +46,16 @@ SCHED_FEAT(DOUBLE_TICK, false) */ SCHED_FEAT(NONTASK_CAPACITY, true) +#ifdef CONFIG_PREEMPT_RT +SCHED_FEAT(TTWU_QUEUE, false) +#else + /* * Queue remote wakeups on the target CPU and process them * using the scheduler IPI. Reduces rq->lock contention/bounces. */ SCHED_FEAT(TTWU_QUEUE, true) +#endif /* * When doing wakeups, attempt to limit superfluous scans of the LLC domain. diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 3daf42a0f462..bb945f8faeca 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1009,8 +1009,10 @@ static void update_curr_rt(struct rq *rq) if (unlikely((s64)delta_exec <= 0)) return; - schedstat_set(curr->se.statistics.exec_max, - max(curr->se.statistics.exec_max, delta_exec)); + schedstat_set(curr->stats.exec_max, + max(curr->stats.exec_max, delta_exec)); + + trace_sched_stat_runtime(curr, delta_exec, 0); curr->se.sum_exec_runtime += delta_exec; account_group_exec_runtime(curr, delta_exec); @@ -1271,6 +1273,112 @@ static void __delist_rt_entity(struct sched_rt_entity *rt_se, struct rt_prio_arr rt_se->on_list = 0; } +static inline struct sched_statistics * +__schedstats_from_rt_se(struct sched_rt_entity *rt_se) +{ +#ifdef CONFIG_RT_GROUP_SCHED + /* schedstats is not supported for rt group. */ + if (!rt_entity_is_task(rt_se)) + return NULL; +#endif + + return &rt_task_of(rt_se)->stats; +} + +static inline void +update_stats_wait_start_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se) +{ + struct sched_statistics *stats; + struct task_struct *p = NULL; + + if (!schedstat_enabled()) + return; + + if (rt_entity_is_task(rt_se)) + p = rt_task_of(rt_se); + + stats = __schedstats_from_rt_se(rt_se); + if (!stats) + return; + + __update_stats_wait_start(rq_of_rt_rq(rt_rq), p, stats); +} + +static inline void +update_stats_enqueue_sleeper_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se) +{ + struct sched_statistics *stats; + struct task_struct *p = NULL; + + if (!schedstat_enabled()) + return; + + if (rt_entity_is_task(rt_se)) + p = rt_task_of(rt_se); + + stats = __schedstats_from_rt_se(rt_se); + if (!stats) + return; + + __update_stats_enqueue_sleeper(rq_of_rt_rq(rt_rq), p, stats); +} + +static inline void +update_stats_enqueue_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, + int flags) +{ + if (!schedstat_enabled()) + return; + + if (flags & ENQUEUE_WAKEUP) + update_stats_enqueue_sleeper_rt(rt_rq, rt_se); +} + +static inline void +update_stats_wait_end_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se) +{ + struct sched_statistics *stats; + struct task_struct *p = NULL; + + if (!schedstat_enabled()) + return; + + if (rt_entity_is_task(rt_se)) + p = rt_task_of(rt_se); + + stats = __schedstats_from_rt_se(rt_se); + if (!stats) + return; + + __update_stats_wait_end(rq_of_rt_rq(rt_rq), p, stats); +} + +static inline void +update_stats_dequeue_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, + int flags) +{ + struct task_struct *p = NULL; + + if (!schedstat_enabled()) + return; + + if (rt_entity_is_task(rt_se)) + p = rt_task_of(rt_se); + + if ((flags & DEQUEUE_SLEEP) && p) { + unsigned int state; + + state = READ_ONCE(p->__state); + if (state & TASK_INTERRUPTIBLE) + __schedstat_set(p->stats.sleep_start, + rq_clock(rq_of_rt_rq(rt_rq))); + + if (state & TASK_UNINTERRUPTIBLE) + __schedstat_set(p->stats.block_start, + rq_clock(rq_of_rt_rq(rt_rq))); + } +} + static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) { struct rt_rq *rt_rq = rt_rq_of_se(rt_se); @@ -1344,6 +1452,8 @@ static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) { struct rq *rq = rq_of_rt_se(rt_se); + update_stats_enqueue_rt(rt_rq_of_se(rt_se), rt_se, flags); + dequeue_rt_stack(rt_se, flags); for_each_sched_rt_entity(rt_se) __enqueue_rt_entity(rt_se, flags); @@ -1354,6 +1464,8 @@ static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) { struct rq *rq = rq_of_rt_se(rt_se); + update_stats_dequeue_rt(rt_rq_of_se(rt_se), rt_se, flags); + dequeue_rt_stack(rt_se, flags); for_each_sched_rt_entity(rt_se) { @@ -1376,6 +1488,9 @@ enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags) if (flags & ENQUEUE_WAKEUP) rt_se->timeout = 0; + check_schedstat_required(); + update_stats_wait_start_rt(rt_rq_of_se(rt_se), rt_se); + enqueue_rt_entity(rt_se, flags); if (!task_current(rq, p) && p->nr_cpus_allowed > 1) @@ -1576,7 +1691,12 @@ static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flag static inline void set_next_task_rt(struct rq *rq, struct task_struct *p, bool first) { + struct sched_rt_entity *rt_se = &p->rt; + struct rt_rq *rt_rq = &rq->rt; + p->se.exec_start = rq_clock_task(rq); + if (on_rt_rq(&p->rt)) + update_stats_wait_end_rt(rt_rq, rt_se); /* The running task is never eligible for pushing */ dequeue_pushable_task(rq, p); @@ -1650,6 +1770,12 @@ static struct task_struct *pick_next_task_rt(struct rq *rq) static void put_prev_task_rt(struct rq *rq, struct task_struct *p) { + struct sched_rt_entity *rt_se = &p->rt; + struct rt_rq *rt_rq = &rq->rt; + + if (on_rt_rq(&p->rt)) + update_stats_wait_start_rt(rt_rq, rt_se); + update_curr_rt(rq); update_rt_rq_load_avg(rq_clock_pelt(rq), rq, 1); diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 66128dfc05fb..56ff343d4119 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -368,6 +368,7 @@ struct cfs_bandwidth { u64 quota; u64 runtime; u64 burst; + u64 runtime_snap; s64 hierarchical_quota; u8 idle; @@ -380,7 +381,9 @@ struct cfs_bandwidth { /* Statistics: */ int nr_periods; int nr_throttled; + int nr_burst; u64 throttled_time; + u64 burst_time; #endif }; @@ -529,6 +532,7 @@ struct cfs_rq { struct load_weight load; unsigned int nr_running; unsigned int h_nr_running; /* SCHED_{NORMAL,BATCH,IDLE} */ + unsigned int idle_nr_running; /* SCHED_IDLE */ unsigned int idle_h_nr_running; /* SCHED_IDLE */ u64 exec_clock; @@ -1253,11 +1257,6 @@ extern void sched_core_dequeue(struct rq *rq, struct task_struct *p); extern void sched_core_get(void); extern void sched_core_put(void); -extern unsigned long sched_core_alloc_cookie(void); -extern void sched_core_put_cookie(unsigned long cookie); -extern unsigned long sched_core_get_cookie(unsigned long cookie); -extern unsigned long sched_core_update_cookie(struct task_struct *p, unsigned long cookie); - #else /* !CONFIG_SCHED_CORE */ static inline bool sched_core_enabled(struct rq *rq) @@ -1421,11 +1420,6 @@ static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) extern void update_rq_clock(struct rq *rq); -static inline u64 __rq_clock_broken(struct rq *rq) -{ - return READ_ONCE(rq->clock); -} - /* * rq::clock_update_flags bits * @@ -1621,14 +1615,6 @@ rq_lock(struct rq *rq, struct rq_flags *rf) } static inline void -rq_relock(struct rq *rq, struct rq_flags *rf) - __acquires(rq->lock) -{ - raw_spin_rq_lock(rq); - rq_repin_lock(rq, rf); -} - -static inline void rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf) __releases(rq->lock) { @@ -1808,6 +1794,7 @@ struct sched_group { unsigned int group_weight; struct sched_group_capacity *sgc; int asym_prefer_cpu; /* CPU of highest priority in group */ + int flags; /* * The CPUs this group covers. @@ -2401,6 +2388,7 @@ extern const_debug unsigned int sysctl_sched_migration_cost; #ifdef CONFIG_SCHED_DEBUG extern unsigned int sysctl_sched_latency; extern unsigned int sysctl_sched_min_granularity; +extern unsigned int sysctl_sched_idle_min_granularity; extern unsigned int sysctl_sched_wakeup_granularity; extern int sysctl_resched_latency_warn_ms; extern int sysctl_resched_latency_warn_once; @@ -2708,12 +2696,18 @@ extern void cfs_bandwidth_usage_dec(void); #define NOHZ_BALANCE_KICK_BIT 0 #define NOHZ_STATS_KICK_BIT 1 #define NOHZ_NEWILB_KICK_BIT 2 +#define NOHZ_NEXT_KICK_BIT 3 +/* Run rebalance_domains() */ #define NOHZ_BALANCE_KICK BIT(NOHZ_BALANCE_KICK_BIT) +/* Update blocked load */ #define NOHZ_STATS_KICK BIT(NOHZ_STATS_KICK_BIT) +/* Update blocked load when entering idle */ #define NOHZ_NEWILB_KICK BIT(NOHZ_NEWILB_KICK_BIT) +/* Update nohz.next_balance */ +#define NOHZ_NEXT_KICK BIT(NOHZ_NEXT_KICK_BIT) -#define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK) +#define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK | NOHZ_NEXT_KICK) #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c index 3f93fc3b5648..07dde2928c79 100644 --- a/kernel/sched/stats.c +++ b/kernel/sched/stats.c @@ -4,6 +4,110 @@ */ #include "sched.h" +void __update_stats_wait_start(struct rq *rq, struct task_struct *p, + struct sched_statistics *stats) +{ + u64 wait_start, prev_wait_start; + + wait_start = rq_clock(rq); + prev_wait_start = schedstat_val(stats->wait_start); + + if (p && likely(wait_start > prev_wait_start)) + wait_start -= prev_wait_start; + + __schedstat_set(stats->wait_start, wait_start); +} + +void __update_stats_wait_end(struct rq *rq, struct task_struct *p, + struct sched_statistics *stats) +{ + u64 delta = rq_clock(rq) - schedstat_val(stats->wait_start); + + if (p) { + if (task_on_rq_migrating(p)) { + /* + * Preserve migrating task's wait time so wait_start + * time stamp can be adjusted to accumulate wait time + * prior to migration. + */ + __schedstat_set(stats->wait_start, delta); + + return; + } + + trace_sched_stat_wait(p, delta); + } + + __schedstat_set(stats->wait_max, + max(schedstat_val(stats->wait_max), delta)); + __schedstat_inc(stats->wait_count); + __schedstat_add(stats->wait_sum, delta); + __schedstat_set(stats->wait_start, 0); +} + +void __update_stats_enqueue_sleeper(struct rq *rq, struct task_struct *p, + struct sched_statistics *stats) +{ + u64 sleep_start, block_start; + + sleep_start = schedstat_val(stats->sleep_start); + block_start = schedstat_val(stats->block_start); + + if (sleep_start) { + u64 delta = rq_clock(rq) - sleep_start; + + if ((s64)delta < 0) + delta = 0; + + if (unlikely(delta > schedstat_val(stats->sleep_max))) + __schedstat_set(stats->sleep_max, delta); + + __schedstat_set(stats->sleep_start, 0); + __schedstat_add(stats->sum_sleep_runtime, delta); + + if (p) { + account_scheduler_latency(p, delta >> 10, 1); + trace_sched_stat_sleep(p, delta); + } + } + + if (block_start) { + u64 delta = rq_clock(rq) - block_start; + + if ((s64)delta < 0) + delta = 0; + + if (unlikely(delta > schedstat_val(stats->block_max))) + __schedstat_set(stats->block_max, delta); + + __schedstat_set(stats->block_start, 0); + __schedstat_add(stats->sum_sleep_runtime, delta); + __schedstat_add(stats->sum_block_runtime, delta); + + if (p) { + if (p->in_iowait) { + __schedstat_add(stats->iowait_sum, delta); + __schedstat_inc(stats->iowait_count); + trace_sched_stat_iowait(p, delta); + } + + trace_sched_stat_blocked(p, delta); + + /* + * Blocking time is in units of nanosecs, so shift by + * 20 to get a milliseconds-range estimation of the + * amount of time that the task spent sleeping: + */ + if (unlikely(prof_on == SLEEP_PROFILING)) { + profile_hits(SLEEP_PROFILING, + (void *)get_wchan(p), + delta >> 20); + } + account_scheduler_latency(p, delta >> 10, 0); + } + } +} + /* * Current schedstat API version. * diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h index d8f8eb0c655b..cfb0893a83d4 100644 --- a/kernel/sched/stats.h +++ b/kernel/sched/stats.h @@ -2,6 +2,8 @@ #ifdef CONFIG_SCHEDSTATS +extern struct static_key_false sched_schedstats; + /* * Expects runqueue lock to be held for atomicity of update */ @@ -40,7 +42,31 @@ rq_sched_info_dequeue(struct rq *rq, unsigned long long delta) #define schedstat_val(var) (var) #define schedstat_val_or_zero(var) ((schedstat_enabled()) ? (var) : 0) +void __update_stats_wait_start(struct rq *rq, struct task_struct *p, + struct sched_statistics *stats); + +void __update_stats_wait_end(struct rq *rq, struct task_struct *p, + struct sched_statistics *stats); +void __update_stats_enqueue_sleeper(struct rq *rq, struct task_struct *p, + struct sched_statistics *stats); + +static inline void +check_schedstat_required(void) +{ + if (schedstat_enabled()) + return; + + /* Force schedstat enabled if a dependent tracepoint is active */ + if (trace_sched_stat_wait_enabled() || + trace_sched_stat_sleep_enabled() || + trace_sched_stat_iowait_enabled() || + trace_sched_stat_blocked_enabled() || + trace_sched_stat_runtime_enabled()) + printk_deferred_once("Scheduler tracepoints stat_sleep, stat_iowait, stat_blocked and stat_runtime require the kernel parameter schedstats=enable or kernel.sched_schedstats=1\n"); +} + #else /* !CONFIG_SCHEDSTATS: */ + static inline void rq_sched_info_arrive (struct rq *rq, unsigned long long delta) { } static inline void rq_sched_info_dequeue(struct rq *rq, unsigned long long delta) { } static inline void rq_sched_info_depart (struct rq *rq, unsigned long long delta) { } @@ -53,8 +79,31 @@ static inline void rq_sched_info_depart (struct rq *rq, unsigned long long delt # define schedstat_set(var, val) do { } while (0) # define schedstat_val(var) 0 # define schedstat_val_or_zero(var) 0 + +# define __update_stats_wait_start(rq, p, stats) do { } while (0) +# define __update_stats_wait_end(rq, p, stats) do { } while (0) +# define __update_stats_enqueue_sleeper(rq, p, stats) do { } while (0) +# define check_schedstat_required() do { } while (0) + #endif /* CONFIG_SCHEDSTATS */ +#ifdef CONFIG_FAIR_GROUP_SCHED +struct sched_entity_stats { + struct sched_entity se; + struct sched_statistics stats; +} __no_randomize_layout; +#endif + +static inline struct sched_statistics * +__schedstats_from_se(struct sched_entity *se) +{ +#ifdef CONFIG_FAIR_GROUP_SCHED + if (!entity_is_task(se)) + return &container_of(se, struct sched_entity_stats, se)->stats; +#endif + return &task_of(se)->stats; +} + #ifdef CONFIG_PSI /* * PSI tracks state that persists across sleeps, such as iowaits and diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c index f988ebe3febb..0b165a25f22f 100644 --- a/kernel/sched/stop_task.c +++ b/kernel/sched/stop_task.c @@ -78,8 +78,8 @@ static void put_prev_task_stop(struct rq *rq, struct task_struct *prev) if (unlikely((s64)delta_exec < 0)) delta_exec = 0; - schedstat_set(curr->se.statistics.exec_max, - max(curr->se.statistics.exec_max, delta_exec)); + schedstat_set(curr->stats.exec_max, + max(curr->stats.exec_max, delta_exec)); curr->se.sum_exec_runtime += delta_exec; account_group_exec_runtime(curr, delta_exec); diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 4e8698e62f07..30169c7685b6 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -526,7 +526,7 @@ static int init_rootdomain(struct root_domain *rd) #ifdef HAVE_RT_PUSH_IPI rd->rto_cpu = -1; raw_spin_lock_init(&rd->rto_lock); - init_irq_work(&rd->rto_push_work, rto_push_irq_work_func); + rd->rto_push_work = IRQ_WORK_INIT_HARD(rto_push_irq_work_func); #endif rd->visit_gen = 0; @@ -688,7 +688,6 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) { struct rq *rq = cpu_rq(cpu); struct sched_domain *tmp; - int numa_distance = 0; /* Remove the sched domains which do not contribute to scheduling. */ for (tmp = sd; tmp; ) { @@ -716,13 +715,22 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) tmp = sd; sd = sd->parent; destroy_sched_domain(tmp); - if (sd) + if (sd) { + struct sched_group *sg = sd->groups; + + /* + * sched groups hold the flags of the child sched + * domain for convenience. Clear such flags since + * the child is being destroyed. + */ + do { + sg->flags = 0; + } while (sg != sd->groups); + sd->child = NULL; + } } - for (tmp = sd; tmp; tmp = tmp->parent) - numa_distance += !!(tmp->flags & SD_NUMA); - sched_domain_debug(sd, cpu); rq_attach_root(rq, rd); @@ -916,10 +924,12 @@ build_group_from_child_sched_domain(struct sched_domain *sd, int cpu) return NULL; sg_span = sched_group_span(sg); - if (sd->child) + if (sd->child) { cpumask_copy(sg_span, sched_domain_span(sd->child)); - else + sg->flags = sd->child->flags; + } else { cpumask_copy(sg_span, sched_domain_span(sd)); + } atomic_inc(&sg->ref); return sg; @@ -1169,6 +1179,7 @@ static struct sched_group *get_group(int cpu, struct sd_data *sdd) if (child) { cpumask_copy(sched_group_span(sg), sched_domain_span(child)); cpumask_copy(group_balance_mask(sg), sched_group_span(sg)); + sg->flags = child->flags; } else { cpumask_set_cpu(cpu, sched_group_span(sg)); cpumask_set_cpu(cpu, group_balance_mask(sg)); @@ -1557,7 +1568,7 @@ sd_init(struct sched_domain_topology_level *tl, .last_balance = jiffies, .balance_interval = sd_weight, .max_newidle_lb_cost = 0, - .next_decay_max_lb_cost = jiffies, + .last_decay_max_lb_cost = jiffies, .child = child, #ifdef CONFIG_SCHED_DEBUG .name = tl->name, @@ -1627,6 +1638,11 @@ static struct sched_domain_topology_level default_topology[] = { #ifdef CONFIG_SCHED_SMT { cpu_smt_mask, cpu_smt_flags, SD_INIT_NAME(SMT) }, #endif + +#ifdef CONFIG_SCHED_CLUSTER + { cpu_clustergroup_mask, cpu_cluster_flags, SD_INIT_NAME(CLS) }, +#endif + #ifdef CONFIG_SCHED_MC { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) }, #endif diff --git a/kernel/smp.c b/kernel/smp.c index f43ede0ab183..01a7c1706a58 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -1170,14 +1170,12 @@ void wake_up_all_idle_cpus(void) { int cpu; - preempt_disable(); - for_each_online_cpu(cpu) { - if (cpu == smp_processor_id()) - continue; - - wake_up_if_idle(cpu); + for_each_possible_cpu(cpu) { + preempt_disable(); + if (cpu != smp_processor_id() && cpu_online(cpu)) + wake_up_if_idle(cpu); + preempt_enable(); } - preempt_enable(); } EXPORT_SYMBOL_GPL(wake_up_all_idle_cpus); |