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authorLinus Torvalds2021-11-01 13:48:52 -0700
committerLinus Torvalds2021-11-01 13:48:52 -0700
commit9a7e0a90a454a7826ecbca055a6ec9271b70c686 (patch)
tree4e432bee81d5a7a480241db62edec2edc40069d5 /kernel
parent57a315cd7198907326e691cc909df2beebc2420d (diff)
parent8ea9183db4ad8afbcb7089a77c23eaf965b0cacd (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.preempt32
-rw-r--r--kernel/exit.c2
-rw-r--r--kernel/fork.c2
-rw-r--r--kernel/irq_work.c130
-rw-r--r--kernel/kprobes.c8
-rw-r--r--kernel/kthread.c16
-rw-r--r--kernel/livepatch/transition.c95
-rw-r--r--kernel/rcu/tasks.h12
-rw-r--r--kernel/rcu/tree_stall.h8
-rw-r--r--kernel/sched/Makefile4
-rw-r--r--kernel/sched/core.c392
-rw-r--r--kernel/sched/core_sched.c9
-rw-r--r--kernel/sched/deadline.c99
-rw-r--r--kernel/sched/debug.c101
-rw-r--r--kernel/sched/fair.c496
-rw-r--r--kernel/sched/features.h5
-rw-r--r--kernel/sched/rt.c130
-rw-r--r--kernel/sched/sched.h32
-rw-r--r--kernel/sched/stats.c104
-rw-r--r--kernel/sched/stats.h49
-rw-r--r--kernel/sched/stop_task.c4
-rw-r--r--kernel/sched/topology.c34
-rw-r--r--kernel/smp.c12
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, &param);
+ 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, &param);
- 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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-16 06:47:40 +0000