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Merge branch 'for-4.17/dax' into libnvdimm-for-next

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This commit is contained in:
Dan Williams
2018-04-09 10:50:17 -07:00
parent 1ed41b5696 976431b02c
commit e13e75b86e
60 changed files with 1630 additions and 1291 deletions
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5
kernel/sched/Makefile
View File

@@ -17,8 +17,9 @@ CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer
endif
obj-y += core.o loadavg.o clock.o cputime.o
obj-y += idle_task.o fair.o rt.o deadline.o
obj-y += wait.o wait_bit.o swait.o completion.o idle.o
obj-y += idle.o fair.o rt.o deadline.o
obj-y += wait.o wait_bit.o swait.o completion.o
obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o topology.o stop_task.o
obj-$(CONFIG_SCHED_AUTOGROUP) += autogroup.o
obj-$(CONFIG_SCHEDSTATS) += stats.o

21
kernel/sched/autogroup.c
View File

@@ -1,10 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/utsname.h>
#include <linux/security.h>
#include <linux/export.h>
/*
* Auto-group scheduling implementation:
*/
#include "sched.h"
unsigned int __read_mostly sysctl_sched_autogroup_enabled = 1;
@@ -168,18 +165,19 @@ autogroup_move_group(struct task_struct *p, struct autogroup *ag)
autogroup_kref_put(prev);
}
/* Allocates GFP_KERNEL, cannot be called under any spinlock */
/* Allocates GFP_KERNEL, cannot be called under any spinlock: */
void sched_autogroup_create_attach(struct task_struct *p)
{
struct autogroup *ag = autogroup_create();
autogroup_move_group(p, ag);
/* drop extra reference added by autogroup_create() */
/* Drop extra reference added by autogroup_create(): */
autogroup_kref_put(ag);
}
EXPORT_SYMBOL(sched_autogroup_create_attach);
/* Cannot be called under siglock. Currently has no users */
/* Cannot be called under siglock. Currently has no users: */
void sched_autogroup_detach(struct task_struct *p)
{
autogroup_move_group(p, &autogroup_default);
@@ -202,7 +200,6 @@ static int __init setup_autogroup(char *str)
return 1;
}
__setup("noautogroup", setup_autogroup);
#ifdef CONFIG_PROC_FS
@@ -224,7 +221,7 @@ int proc_sched_autogroup_set_nice(struct task_struct *p, int nice)
if (nice < 0 && !can_nice(current, nice))
return -EPERM;
/* this is a heavy operation taking global locks.. */
/* This is a heavy operation, taking global locks.. */
if (!capable(CAP_SYS_ADMIN) && time_before(jiffies, next))
return -EAGAIN;
@@ -267,4 +264,4 @@ int autogroup_path(struct task_group *tg, char *buf, int buflen)
return snprintf(buf, buflen, "%s-%ld", "/autogroup", tg->autogroup->id);
}
#endif /* CONFIG_SCHED_DEBUG */
#endif

12
kernel/sched/autogroup.h
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@@ -1,15 +1,11 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifdef CONFIG_SCHED_AUTOGROUP
#include <linux/kref.h>
#include <linux/rwsem.h>
#include <linux/sched/autogroup.h>
struct autogroup {
/*
* reference doesn't mean how many thread attach to this
* autogroup now. It just stands for the number of task
* could use this autogroup.
* Reference doesn't mean how many threads attach to this
* autogroup now. It just stands for the number of tasks
* which could use this autogroup.
*/
struct kref kref;
struct task_group *tg;
@@ -56,11 +52,9 @@ autogroup_task_group(struct task_struct *p, struct task_group *tg)
return tg;
}
#ifdef CONFIG_SCHED_DEBUG
static inline int autogroup_path(struct task_group *tg, char *buf, int buflen)
{
return 0;
}
#endif
#endif /* CONFIG_SCHED_AUTOGROUP */

36
kernel/sched/clock.c
View File

@@ -1,5 +1,5 @@
/*
* sched_clock for unstable cpu clocks
* sched_clock() for unstable CPU clocks
*
* Copyright (C) 2008 Red Hat, Inc., Peter Zijlstra
*
@@ -11,7 +11,7 @@
* Guillaume Chazarain <guichaz@gmail.com>
*
*
* What:
* What this file implements:
*
* cpu_clock(i) provides a fast (execution time) high resolution
* clock with bounded drift between CPUs. The value of cpu_clock(i)
@@ -26,11 +26,11 @@
* at 0 on boot (but people really shouldn't rely on that).
*
* cpu_clock(i) -- can be used from any context, including NMI.
* local_clock() -- is cpu_clock() on the current cpu.
* local_clock() -- is cpu_clock() on the current CPU.
*
* sched_clock_cpu(i)
*
* How:
* How it is implemented:
*
* The implementation either uses sched_clock() when
* !CONFIG_HAVE_UNSTABLE_SCHED_CLOCK, which means in that case the
@@ -52,19 +52,7 @@
* that is otherwise invisible (TSC gets stopped).
*
*/
#include <linux/spinlock.h>
#include <linux/hardirq.h>
#include <linux/export.h>
#include <linux/percpu.h>
#include <linux/ktime.h>
#include <linux/sched.h>
#include <linux/nmi.h>
#include <linux/sched/clock.h>
#include <linux/static_key.h>
#include <linux/workqueue.h>
#include <linux/compiler.h>
#include <linux/tick.h>
#include <linux/init.h>
#include "sched.h"
/*
* Scheduler clock - returns current time in nanosec units.
@@ -302,21 +290,21 @@ again:
* cmpxchg64 below only protects one readout.
*
* We must reread via sched_clock_local() in the retry case on
* 32bit as an NMI could use sched_clock_local() via the
* 32-bit kernels as an NMI could use sched_clock_local() via the
* tracer and hit between the readout of
* the low32bit and the high 32bit portion.
* the low 32-bit and the high 32-bit portion.
*/
this_clock = sched_clock_local(my_scd);
/*
* We must enforce atomic readout on 32bit, otherwise the
* update on the remote cpu can hit inbetween the readout of
* the low32bit and the high 32bit portion.
* We must enforce atomic readout on 32-bit, otherwise the
* update on the remote CPU can hit inbetween the readout of
* the low 32-bit and the high 32-bit portion.
*/
remote_clock = cmpxchg64(&scd->clock, 0, 0);
#else
/*
* On 64bit the read of [my]scd->clock is atomic versus the
* update, so we can avoid the above 32bit dance.
* On 64-bit kernels the read of [my]scd->clock is atomic versus the
* update, so we can avoid the above 32-bit dance.
*/
sched_clock_local(my_scd);
again:

5
kernel/sched/completion.c
View File

@@ -11,10 +11,7 @@
* typically be used for exclusion which gives rise to priority inversion.
* Waiting for completion is a typically sync point, but not an exclusion point.
*/
#include <linux/sched/signal.h>
#include <linux/sched/debug.h>
#include <linux/completion.h>
#include "sched.h"
/**
* complete: - signals a single thread waiting on this completion

165
kernel/sched/core.c
View File

@@ -5,37 +5,11 @@
*
* Copyright (C) 1991-2002 Linus Torvalds
*/
#include <linux/sched.h>
#include <linux/sched/clock.h>
#include <uapi/linux/sched/types.h>
#include <linux/sched/loadavg.h>
#include <linux/sched/hotplug.h>
#include <linux/wait_bit.h>
#include <linux/cpuset.h>
#include <linux/delayacct.h>
#include <linux/init_task.h>
#include <linux/context_tracking.h>
#include <linux/rcupdate_wait.h>
#include <linux/compat.h>
#include <linux/blkdev.h>
#include <linux/kprobes.h>
#include <linux/mmu_context.h>
#include <linux/module.h>
#include <linux/nmi.h>
#include <linux/prefetch.h>
#include <linux/profile.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/sched/isolation.h>
#include "sched.h"
#include <asm/switch_to.h>
#include <asm/tlb.h>
#ifdef CONFIG_PARAVIRT
#include <asm/paravirt.h>
#endif
#include "sched.h"
#include "../workqueue_internal.h"
#include "../smpboot.h"
@@ -135,7 +109,7 @@ struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf)
* [L] ->on_rq
* RELEASE (rq->lock)
*
* If we observe the old cpu in task_rq_lock, the acquire of
* If we observe the old CPU in task_rq_lock, the acquire of
* the old rq->lock will fully serialize against the stores.
*
* If we observe the new CPU in task_rq_lock, the acquire will
@@ -333,7 +307,7 @@ void hrtick_start(struct rq *rq, u64 delay)
}
#endif /* CONFIG_SMP */
static void init_rq_hrtick(struct rq *rq)
static void hrtick_rq_init(struct rq *rq)
{
#ifdef CONFIG_SMP
rq->hrtick_csd_pending = 0;
@@ -351,7 +325,7 @@ static inline void hrtick_clear(struct rq *rq)
{
}
static inline void init_rq_hrtick(struct rq *rq)
static inline void hrtick_rq_init(struct rq *rq)
{
}
#endif /* CONFIG_SCHED_HRTICK */
@@ -1457,7 +1431,7 @@ EXPORT_SYMBOL_GPL(kick_process);
*
* - cpu_active must be a subset of cpu_online
*
* - on cpu-up we allow per-cpu kthreads on the online && !active cpu,
* - on CPU-up we allow per-CPU kthreads on the online && !active CPU,
* see __set_cpus_allowed_ptr(). At this point the newly online
* CPU isn't yet part of the sched domains, and balancing will not
* see it.
@@ -2629,6 +2603,18 @@ static inline void finish_lock_switch(struct rq *rq)
raw_spin_unlock_irq(&rq->lock);
}
/*
* NOP if the arch has not defined these:
*/
#ifndef prepare_arch_switch
# define prepare_arch_switch(next) do { } while (0)
#endif
#ifndef finish_arch_post_lock_switch
# define finish_arch_post_lock_switch() do { } while (0)
#endif
/**
* prepare_task_switch - prepare to switch tasks
* @rq: the runqueue preparing to switch
@@ -3037,7 +3023,7 @@ unsigned long long task_sched_runtime(struct task_struct *p)
#if defined(CONFIG_64BIT) && defined(CONFIG_SMP)
/*
* 64-bit doesn't need locks to atomically read a 64bit value.
* 64-bit doesn't need locks to atomically read a 64-bit value.
* So we have a optimization chance when the task's delta_exec is 0.
* Reading ->on_cpu is racy, but this is ok.
*
@@ -3096,35 +3082,99 @@ void scheduler_tick(void)
rq->idle_balance = idle_cpu(cpu);
trigger_load_balance(rq);
#endif
rq_last_tick_reset(rq);
}
#ifdef CONFIG_NO_HZ_FULL
/**
* scheduler_tick_max_deferment
*
* Keep at least one tick per second when a single
* active task is running because the scheduler doesn't
* yet completely support full dynticks environment.
*
* This makes sure that uptime, CFS vruntime, load
* balancing, etc... continue to move forward, even
* with a very low granularity.
*
* Return: Maximum deferment in nanoseconds.
*/
u64 scheduler_tick_max_deferment(void)
struct tick_work {
int cpu;
struct delayed_work work;
};
static struct tick_work __percpu *tick_work_cpu;
static void sched_tick_remote(struct work_struct *work)
{
struct rq *rq = this_rq();
unsigned long next, now = READ_ONCE(jiffies);
struct delayed_work *dwork = to_delayed_work(work);
struct tick_work *twork = container_of(dwork, struct tick_work, work);
int cpu = twork->cpu;
struct rq *rq = cpu_rq(cpu);
struct rq_flags rf;
next = rq->last_sched_tick + HZ;
/*
* Handle the tick only if it appears the remote CPU is running in full
* dynticks mode. The check is racy by nature, but missing a tick or
* having one too much is no big deal because the scheduler tick updates
* statistics and checks timeslices in a time-independent way, regardless
* of when exactly it is running.
*/
if (!idle_cpu(cpu) && tick_nohz_tick_stopped_cpu(cpu)) {
struct task_struct *curr;
u64 delta;
if (time_before_eq(next, now))
return 0;
rq_lock_irq(rq, &rf);
update_rq_clock(rq);
curr = rq->curr;
delta = rq_clock_task(rq) - curr->se.exec_start;
return jiffies_to_nsecs(next - now);
/*
* Make sure the next tick runs within a reasonable
* amount of time.
*/
WARN_ON_ONCE(delta > (u64)NSEC_PER_SEC * 3);
curr->sched_class->task_tick(rq, curr, 0);
rq_unlock_irq(rq, &rf);
}
/*
* Run the remote tick once per second (1Hz). This arbitrary
* frequency is large enough to avoid overload but short enough
* to keep scheduler internal stats reasonably up to date.
*/
queue_delayed_work(system_unbound_wq, dwork, HZ);
}
static void sched_tick_start(int cpu)
{
struct tick_work *twork;
if (housekeeping_cpu(cpu, HK_FLAG_TICK))
return;
WARN_ON_ONCE(!tick_work_cpu);
twork = per_cpu_ptr(tick_work_cpu, cpu);
twork->cpu = cpu;
INIT_DELAYED_WORK(&twork->work, sched_tick_remote);
queue_delayed_work(system_unbound_wq, &twork->work, HZ);
}
#ifdef CONFIG_HOTPLUG_CPU
static void sched_tick_stop(int cpu)
{
struct tick_work *twork;
if (housekeeping_cpu(cpu, HK_FLAG_TICK))
return;
WARN_ON_ONCE(!tick_work_cpu);
twork = per_cpu_ptr(tick_work_cpu, cpu);
cancel_delayed_work_sync(&twork->work);
}
#endif /* CONFIG_HOTPLUG_CPU */
int __init sched_tick_offload_init(void)
{
tick_work_cpu = alloc_percpu(struct tick_work);
BUG_ON(!tick_work_cpu);
return 0;
}
#else /* !CONFIG_NO_HZ_FULL */
static inline void sched_tick_start(int cpu) { }
static inline void sched_tick_stop(int cpu) { }
#endif
#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
@@ -5786,6 +5836,7 @@ int sched_cpu_starting(unsigned int cpu)
{
set_cpu_rq_start_time(cpu);
sched_rq_cpu_starting(cpu);
sched_tick_start(cpu);
return 0;
}
@@ -5797,6 +5848,7 @@ int sched_cpu_dying(unsigned int cpu)
/* Handle pending wakeups and then migrate everything off */
sched_ttwu_pending();
sched_tick_stop(cpu);
rq_lock_irqsave(rq, &rf);
if (rq->rd) {
@@ -6024,11 +6076,8 @@ void __init sched_init(void)
rq->last_load_update_tick = jiffies;
rq->nohz_flags = 0;
#endif
#ifdef CONFIG_NO_HZ_FULL
rq->last_sched_tick = 0;
#endif
#endif /* CONFIG_SMP */
init_rq_hrtick(rq);
hrtick_rq_init(rq);
atomic_set(&rq->nr_iowait, 0);
}
@@ -7027,3 +7076,5 @@ const u32 sched_prio_to_wmult[40] = {
/* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717,
/* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
};
#undef CREATE_TRACE_POINTS

33
kernel/sched/cpuacct.c
View File

@@ -1,24 +1,13 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/cgroup.h>
#include <linux/slab.h>
#include <linux/percpu.h>
#include <linux/spinlock.h>
#include <linux/cpumask.h>
#include <linux/seq_file.h>
#include <linux/rcupdate.h>
#include <linux/kernel_stat.h>
#include <linux/err.h>
#include "sched.h"
/*
* CPU accounting code for task groups.
*
* Based on the work by Paul Menage (menage@google.com) and Balbir Singh
* (balbir@in.ibm.com).
*/
#include "sched.h"
/* Time spent by the tasks of the cpu accounting group executing in ... */
/* Time spent by the tasks of the CPU accounting group executing in ... */
enum cpuacct_stat_index {
CPUACCT_STAT_USER, /* ... user mode */
CPUACCT_STAT_SYSTEM, /* ... kernel mode */
@@ -35,12 +24,12 @@ struct cpuacct_usage {
u64 usages[CPUACCT_STAT_NSTATS];
};
/* track cpu usage of a group of tasks and its child groups */
/* track CPU usage of a group of tasks and its child groups */
struct cpuacct {
struct cgroup_subsys_state css;
/* cpuusage holds pointer to a u64-type object on every cpu */
struct cpuacct_usage __percpu *cpuusage;
struct kernel_cpustat __percpu *cpustat;
struct cgroup_subsys_state css;
/* cpuusage holds pointer to a u64-type object on every CPU */
struct cpuacct_usage __percpu *cpuusage;
struct kernel_cpustat __percpu *cpustat;
};
static inline struct cpuacct *css_ca(struct cgroup_subsys_state *css)
@@ -48,7 +37,7 @@ static inline struct cpuacct *css_ca(struct cgroup_subsys_state *css)
return css ? container_of(css, struct cpuacct, css) : NULL;
}
/* return cpu accounting group to which this task belongs */
/* Return CPU accounting group to which this task belongs */
static inline struct cpuacct *task_ca(struct task_struct *tsk)
{
return css_ca(task_css(tsk, cpuacct_cgrp_id));
@@ -65,7 +54,7 @@ static struct cpuacct root_cpuacct = {
.cpuusage = &root_cpuacct_cpuusage,
};
/* create a new cpu accounting group */
/* Create a new CPU accounting group */
static struct cgroup_subsys_state *
cpuacct_css_alloc(struct cgroup_subsys_state *parent_css)
{
@@ -96,7 +85,7 @@ out:
return ERR_PTR(-ENOMEM);
}
/* destroy an existing cpu accounting group */
/* Destroy an existing CPU accounting group */
static void cpuacct_css_free(struct cgroup_subsys_state *css)
{
struct cpuacct *ca = css_ca(css);
@@ -162,7 +151,7 @@ static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
#endif
}
/* return total cpu usage (in nanoseconds) of a group */
/* Return total CPU usage (in nanoseconds) of a group */
static u64 __cpuusage_read(struct cgroup_subsys_state *css,
enum cpuacct_stat_index index)
{

23
kernel/sched/cpudeadline.c
View File

@@ -10,11 +10,7 @@
* as published by the Free Software Foundation; version 2
* of the License.
*/
#include <linux/gfp.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include "cpudeadline.h"
#include "sched.h"
static inline int parent(int i)
{
@@ -42,8 +38,9 @@ static void cpudl_heapify_down(struct cpudl *cp, int idx)
return;
/* adapted from lib/prio_heap.c */
while(1) {
while (1) {
u64 largest_dl;
l = left_child(idx);
r = right_child(idx);
largest = idx;
@@ -131,6 +128,7 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p,
return 1;
} else {
int best_cpu = cpudl_maximum(cp);
WARN_ON(best_cpu != -1 && !cpu_present(best_cpu));
if (cpumask_test_cpu(best_cpu, &p->cpus_allowed) &&
@@ -145,9 +143,9 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p,
}
/*
* cpudl_clear - remove a cpu from the cpudl max-heap
* cpudl_clear - remove a CPU from the cpudl max-heap
* @cp: the cpudl max-heap context
* @cpu: the target cpu
* @cpu: the target CPU
*
* Notes: assumes cpu_rq(cpu)->lock is locked
*
@@ -186,8 +184,8 @@ void cpudl_clear(struct cpudl *cp, int cpu)
/*
* cpudl_set - update the cpudl max-heap
* @cp: the cpudl max-heap context
* @cpu: the target cpu
* @dl: the new earliest deadline for this cpu
* @cpu: the target CPU
* @dl: the new earliest deadline for this CPU
*
* Notes: assumes cpu_rq(cpu)->lock is locked
*
@@ -205,6 +203,7 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl)
old_idx = cp->elements[cpu].idx;
if (old_idx == IDX_INVALID) {
int new_idx = cp->size++;
cp->elements[new_idx].dl = dl;
cp->elements[new_idx].cpu = cpu;
cp->elements[cpu].idx = new_idx;
@@ -221,7 +220,7 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl)
/*
* cpudl_set_freecpu - Set the cpudl.free_cpus
* @cp: the cpudl max-heap context
* @cpu: rd attached cpu
* @cpu: rd attached CPU
*/
void cpudl_set_freecpu(struct cpudl *cp, int cpu)
{
@@ -231,7 +230,7 @@ void cpudl_set_freecpu(struct cpudl *cp, int cpu)
/*
* cpudl_clear_freecpu - Clear the cpudl.free_cpus
* @cp: the cpudl max-heap context
* @cpu: rd attached cpu
* @cpu: rd attached CPU
*/
void cpudl_clear_freecpu(struct cpudl *cp, int cpu)
{

29
kernel/sched/cpudeadline.h
View File

@@ -1,35 +1,26 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_CPUDL_H
#define _LINUX_CPUDL_H
#include <linux/sched.h>
#include <linux/sched/deadline.h>
#define IDX_INVALID -1
#define IDX_INVALID -1
struct cpudl_item {
u64 dl;
int cpu;
int idx;
u64 dl;
int cpu;
int idx;
};
struct cpudl {
raw_spinlock_t lock;
int size;
cpumask_var_t free_cpus;
struct cpudl_item *elements;
raw_spinlock_t lock;
int size;
cpumask_var_t free_cpus;
struct cpudl_item *elements;
};
#ifdef CONFIG_SMP
int cpudl_find(struct cpudl *cp, struct task_struct *p,
struct cpumask *later_mask);
int cpudl_find(struct cpudl *cp, struct task_struct *p, struct cpumask *later_mask);
void cpudl_set(struct cpudl *cp, int cpu, u64 dl);
void cpudl_clear(struct cpudl *cp, int cpu);
int cpudl_init(struct cpudl *cp);
int cpudl_init(struct cpudl *cp);
void cpudl_set_freecpu(struct cpudl *cp, int cpu);
void cpudl_clear_freecpu(struct cpudl *cp, int cpu);
void cpudl_cleanup(struct cpudl *cp);
#endif /* CONFIG_SMP */
#endif /* _LINUX_CPUDL_H */

1
kernel/sched/cpufreq.c
View File

@@ -8,7 +8,6 @@
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include "sched.h"
DEFINE_PER_CPU(struct update_util_data *, cpufreq_update_util_data);

129
kernel/sched/cpufreq_schedutil.c
View File

@@ -11,61 +11,57 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/cpufreq.h>
#include <linux/kthread.h>
#include <uapi/linux/sched/types.h>
#include <linux/slab.h>
#include <trace/events/power.h>
#include "sched.h"
#include <trace/events/power.h>
struct sugov_tunables {
struct gov_attr_set attr_set;
unsigned int rate_limit_us;
struct gov_attr_set attr_set;
unsigned int rate_limit_us;
};
struct sugov_policy {
struct cpufreq_policy *policy;
struct cpufreq_policy *policy;
struct sugov_tunables *tunables;
struct list_head tunables_hook;
struct sugov_tunables *tunables;
struct list_head tunables_hook;
raw_spinlock_t update_lock; /* For shared policies */
u64 last_freq_update_time;
s64 freq_update_delay_ns;
unsigned int next_freq;
unsigned int cached_raw_freq;
raw_spinlock_t update_lock; /* For shared policies */
u64 last_freq_update_time;
s64 freq_update_delay_ns;
unsigned int next_freq;
unsigned int cached_raw_freq;
/* The next fields are only needed if fast switch cannot be used. */
struct irq_work irq_work;
struct kthread_work work;
struct mutex work_lock;
struct kthread_worker worker;
struct task_struct *thread;
bool work_in_progress;
/* The next fields are only needed if fast switch cannot be used: */
struct irq_work irq_work;
struct kthread_work work;
struct mutex work_lock;
struct kthread_worker worker;
struct task_struct *thread;
bool work_in_progress;
bool need_freq_update;
bool need_freq_update;
};
struct sugov_cpu {
struct update_util_data update_util;
struct sugov_policy *sg_policy;
unsigned int cpu;
struct update_util_data update_util;
struct sugov_policy *sg_policy;
unsigned int cpu;
bool iowait_boost_pending;
unsigned int iowait_boost;
unsigned int iowait_boost_max;
bool iowait_boost_pending;
unsigned int iowait_boost;
unsigned int iowait_boost_max;
u64 last_update;
/* The fields below are only needed when sharing a policy. */
unsigned long util_cfs;
unsigned long util_dl;
unsigned long max;
unsigned int flags;
/* The fields below are only needed when sharing a policy: */
unsigned long util_cfs;
unsigned long util_dl;
unsigned long max;
unsigned int flags;
/* The field below is for single-CPU policies only. */
/* The field below is for single-CPU policies only: */
#ifdef CONFIG_NO_HZ_COMMON
unsigned long saved_idle_calls;
unsigned long saved_idle_calls;
#endif
};
@@ -79,9 +75,9 @@ static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time)
/*
* Since cpufreq_update_util() is called with rq->lock held for
* the @target_cpu, our per-cpu data is fully serialized.
* the @target_cpu, our per-CPU data is fully serialized.
*
* However, drivers cannot in general deal with cross-cpu
* However, drivers cannot in general deal with cross-CPU
* requests, so while get_next_freq() will work, our
* sugov_update_commit() call may not for the fast switching platforms.
*
@@ -111,6 +107,7 @@ static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time)
}
delta_ns = time - sg_policy->last_freq_update_time;
return delta_ns >= sg_policy->freq_update_delay_ns;
}
@@ -345,8 +342,8 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time)
return get_next_freq(sg_policy, util, max);
}
static void sugov_update_shared(struct update_util_data *hook, u64 time,
unsigned int flags)
static void
sugov_update_shared(struct update_util_data *hook, u64 time, unsigned int flags)
{
struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util);
struct sugov_policy *sg_policy = sg_cpu->sg_policy;
@@ -423,8 +420,8 @@ static ssize_t rate_limit_us_show(struct gov_attr_set *attr_set, char *buf)
return sprintf(buf, "%u\n", tunables->rate_limit_us);
}
static ssize_t rate_limit_us_store(struct gov_attr_set *attr_set, const char *buf,
size_t count)
static ssize_t
rate_limit_us_store(struct gov_attr_set *attr_set, const char *buf, size_t count)
{
struct sugov_tunables *tunables = to_sugov_tunables(attr_set);
struct sugov_policy *sg_policy;
@@ -479,11 +476,11 @@ static int sugov_kthread_create(struct sugov_policy *sg_policy)
{
struct task_struct *thread;
struct sched_attr attr = {
.size = sizeof(struct sched_attr),
.sched_policy = SCHED_DEADLINE,
.sched_flags = SCHED_FLAG_SUGOV,
.sched_nice = 0,
.sched_priority = 0,
.size = sizeof(struct sched_attr),
.sched_policy = SCHED_DEADLINE,
.sched_flags = SCHED_FLAG_SUGOV,
.sched_nice = 0,
.sched_priority = 0,
/*
* Fake (unused) bandwidth; workaround to "fix"
* priority inheritance.
@@ -663,21 +660,21 @@ static int sugov_start(struct cpufreq_policy *policy)
struct sugov_policy *sg_policy = policy->governor_data;
unsigned int cpu;
sg_policy->freq_update_delay_ns = sg_policy->tunables->rate_limit_us * NSEC_PER_USEC;
sg_policy->last_freq_update_time = 0;
sg_policy->next_freq = UINT_MAX;
sg_policy->work_in_progress = false;
sg_policy->need_freq_update = false;
sg_policy->cached_raw_freq = 0;
sg_policy->freq_update_delay_ns = sg_policy->tunables->rate_limit_us * NSEC_PER_USEC;
sg_policy->last_freq_update_time = 0;
sg_policy->next_freq = UINT_MAX;
sg_policy->work_in_progress = false;
sg_policy->need_freq_update = false;
sg_policy->cached_raw_freq = 0;
for_each_cpu(cpu, policy->cpus) {
struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu);
memset(sg_cpu, 0, sizeof(*sg_cpu));
sg_cpu->cpu = cpu;
sg_cpu->sg_policy = sg_policy;
sg_cpu->flags = 0;
sg_cpu->iowait_boost_max = policy->cpuinfo.max_freq;
sg_cpu->cpu = cpu;
sg_cpu->sg_policy = sg_policy;
sg_cpu->flags = 0;
sg_cpu->iowait_boost_max = policy->cpuinfo.max_freq;
}
for_each_cpu(cpu, policy->cpus) {
@@ -721,14 +718,14 @@ static void sugov_limits(struct cpufreq_policy *policy)
}
static struct cpufreq_governor schedutil_gov = {
.name = "schedutil",
.owner = THIS_MODULE,
.dynamic_switching = true,
.init = sugov_init,
.exit = sugov_exit,
.start = sugov_start,
.stop = sugov_stop,
.limits = sugov_limits,
.name = "schedutil",
.owner = THIS_MODULE,
.dynamic_switching = true,
.init = sugov_init,
.exit = sugov_exit,
.start = sugov_start,
.stop = sugov_stop,
.limits = sugov_limits,
};
#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL

15
kernel/sched/cpupri.c
View File

@@ -14,7 +14,7 @@
*
* going from the lowest priority to the highest. CPUs in the INVALID state
* are not eligible for routing. The system maintains this state with
* a 2 dimensional bitmap (the first for priority class, the second for cpus
* a 2 dimensional bitmap (the first for priority class, the second for CPUs
* in that class). Therefore a typical application without affinity
* restrictions can find a suitable CPU with O(1) complexity (e.g. two bit
* searches). For tasks with affinity restrictions, the algorithm has a
@@ -26,12 +26,7 @@
* as published by the Free Software Foundation; version 2
* of the License.
*/
#include <linux/gfp.h>
#include <linux/sched.h>
#include <linux/sched/rt.h>
#include <linux/slab.h>
#include "cpupri.h"
#include "sched.h"
/* Convert between a 140 based task->prio, and our 102 based cpupri */
static int convert_prio(int prio)
@@ -128,9 +123,9 @@ int cpupri_find(struct cpupri *cp, struct task_struct *p,
}
/**
* cpupri_set - update the cpu priority setting
* cpupri_set - update the CPU priority setting
* @cp: The cpupri context
* @cpu: The target cpu
* @cpu: The target CPU
* @newpri: The priority (INVALID-RT99) to assign to this CPU
*
* Note: Assumes cpu_rq(cpu)->lock is locked
@@ -151,7 +146,7 @@ void cpupri_set(struct cpupri *cp, int cpu, int newpri)
return;
/*
* If the cpu was currently mapped to a different value, we
* If the CPU was currently mapped to a different value, we
* need to map it to the new value then remove the old value.
* Note, we must add the new value first, otherwise we risk the
* cpu being missed by the priority loop in cpupri_find.

25
kernel/sched/cpupri.h
View File

@@ -1,32 +1,25 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_CPUPRI_H
#define _LINUX_CPUPRI_H
#include <linux/sched.h>
#define CPUPRI_NR_PRIORITIES (MAX_RT_PRIO + 2)
#define CPUPRI_INVALID -1
#define CPUPRI_IDLE 0
#define CPUPRI_NORMAL 1
#define CPUPRI_INVALID -1
#define CPUPRI_IDLE 0
#define CPUPRI_NORMAL 1
/* values 2-101 are RT priorities 0-99 */
struct cpupri_vec {
atomic_t count;
cpumask_var_t mask;
atomic_t count;
cpumask_var_t mask;
};
struct cpupri {
struct cpupri_vec pri_to_cpu[CPUPRI_NR_PRIORITIES];
int *cpu_to_pri;
struct cpupri_vec pri_to_cpu[CPUPRI_NR_PRIORITIES];
int *cpu_to_pri;
};
#ifdef CONFIG_SMP
int cpupri_find(struct cpupri *cp,
struct task_struct *p, struct cpumask *lowest_mask);
int cpupri_find(struct cpupri *cp, struct task_struct *p, struct cpumask *lowest_mask);
void cpupri_set(struct cpupri *cp, int cpu, int pri);
int cpupri_init(struct cpupri *cp);
int cpupri_init(struct cpupri *cp);
void cpupri_cleanup(struct cpupri *cp);
#endif
#endif /* _LINUX_CPUPRI_H */

58
kernel/sched/cputime.c
View File

@@ -1,10 +1,6 @@
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/tsacct_kern.h>
#include <linux/kernel_stat.h>
#include <linux/static_key.h>
#include <linux/context_tracking.h>
#include <linux/sched/cputime.h>
/*
* Simple CPU accounting cgroup controller
*/
#include "sched.h"
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
@@ -113,9 +109,9 @@ static inline void task_group_account_field(struct task_struct *p, int index,
}
/*
* Account user cpu time to a process.
* @p: the process that the cpu time gets accounted to
* @cputime: the cpu time spent in user space since the last update
* Account user CPU time to a process.
* @p: the process that the CPU time gets accounted to
* @cputime: the CPU time spent in user space since the last update
*/
void account_user_time(struct task_struct *p, u64 cputime)
{
@@ -135,9 +131,9 @@ void account_user_time(struct task_struct *p, u64 cputime)
}
/*
* Account guest cpu time to a process.
* @p: the process that the cpu time gets accounted to
* @cputime: the cpu time spent in virtual machine since the last update
* Account guest CPU time to a process.
* @p: the process that the CPU time gets accounted to
* @cputime: the CPU time spent in virtual machine since the last update
*/
void account_guest_time(struct task_struct *p, u64 cputime)
{
@@ -159,9 +155,9 @@ void account_guest_time(struct task_struct *p, u64 cputime)
}
/*
* Account system cpu time to a process and desired cpustat field
* @p: the process that the cpu time gets accounted to
* @cputime: the cpu time spent in kernel space since the last update
* Account system CPU time to a process and desired cpustat field
* @p: the process that the CPU time gets accounted to
* @cputime: the CPU time spent in kernel space since the last update
* @index: pointer to cpustat field that has to be updated
*/
void account_system_index_time(struct task_struct *p,
@@ -179,10 +175,10 @@ void account_system_index_time(struct task_struct *p,
}
/*
* Account system cpu time to a process.
* @p: the process that the cpu time gets accounted to
* Account system CPU time to a process.
* @p: the process that the CPU time gets accounted to
* @hardirq_offset: the offset to subtract from hardirq_count()
* @cputime: the cpu time spent in kernel space since the last update
* @cputime: the CPU time spent in kernel space since the last update
*/
void account_system_time(struct task_struct *p, int hardirq_offset, u64 cputime)
{
@@ -205,7 +201,7 @@ void account_system_time(struct task_struct *p, int hardirq_offset, u64 cputime)
/*
* Account for involuntary wait time.
* @cputime: the cpu time spent in involuntary wait
* @cputime: the CPU time spent in involuntary wait
*/
void account_steal_time(u64 cputime)
{
@@ -216,7 +212,7 @@ void account_steal_time(u64 cputime)
/*
* Account for idle time.
* @cputime: the cpu time spent in idle wait
* @cputime: the CPU time spent in idle wait
*/
void account_idle_time(u64 cputime)
{
@@ -338,7 +334,7 @@ void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
/*
* Account a tick to a process and cpustat
* @p: the process that the cpu time gets accounted to
* @p: the process that the CPU time gets accounted to
* @user_tick: is the tick from userspace
* @rq: the pointer to rq
*
@@ -400,17 +396,16 @@ static void irqtime_account_idle_ticks(int ticks)
irqtime_account_process_tick(current, 0, rq, ticks);
}
#else /* CONFIG_IRQ_TIME_ACCOUNTING */
static inline void irqtime_account_idle_ticks(int ticks) {}
static inline void irqtime_account_idle_ticks(int ticks) { }
static inline void irqtime_account_process_tick(struct task_struct *p, int user_tick,
struct rq *rq, int nr_ticks) {}
struct rq *rq, int nr_ticks) { }
#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
/*
* Use precise platform statistics if available:
*/
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
#ifndef __ARCH_HAS_VTIME_TASK_SWITCH
# ifndef __ARCH_HAS_VTIME_TASK_SWITCH
void vtime_common_task_switch(struct task_struct *prev)
{
if (is_idle_task(prev))
@@ -421,8 +416,7 @@ void vtime_common_task_switch(struct task_struct *prev)
vtime_flush(prev);
arch_vtime_task_switch(prev);
}
#endif
# endif
#endif /* CONFIG_VIRT_CPU_ACCOUNTING */
@@ -469,10 +463,12 @@ void thread_group_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st)
*ut = cputime.utime;
*st = cputime.stime;
}
#else /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
#else /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE: */
/*
* Account a single tick of cpu time.
* @p: the process that the cpu time gets accounted to
* Account a single tick of CPU time.
* @p: the process that the CPU time gets accounted to
* @user_tick: indicates if the tick is a user or a system tick
*/
void account_process_tick(struct task_struct *p, int user_tick)

78
kernel/sched/deadline.c
View File

@@ -17,9 +17,6 @@
*/
#include "sched.h"
#include <linux/slab.h>
#include <uapi/linux/sched/types.h>
struct dl_bandwidth def_dl_bandwidth;
static inline struct task_struct *dl_task_of(struct sched_dl_entity *dl_se)
@@ -514,7 +511,7 @@ static DEFINE_PER_CPU(struct callback_head, dl_pull_head);
static void push_dl_tasks(struct rq *);
static void pull_dl_task(struct rq *);
static inline void queue_push_tasks(struct rq *rq)
static inline void deadline_queue_push_tasks(struct rq *rq)
{
if (!has_pushable_dl_tasks(rq))
return;
@@ -522,7 +519,7 @@ static inline void queue_push_tasks(struct rq *rq)
queue_balance_callback(rq, &per_cpu(dl_push_head, rq->cpu), push_dl_tasks);
}
static inline void queue_pull_task(struct rq *rq)
static inline void deadline_queue_pull_task(struct rq *rq)
{
queue_balance_callback(rq, &per_cpu(dl_pull_head, rq->cpu), pull_dl_task);
}
@@ -539,12 +536,12 @@ static struct rq *dl_task_offline_migration(struct rq *rq, struct task_struct *p
/*
* If we cannot preempt any rq, fall back to pick any
* online cpu.
* online CPU:
*/
cpu = cpumask_any_and(cpu_active_mask, &p->cpus_allowed);
if (cpu >= nr_cpu_ids) {
/*
* Fail to find any suitable cpu.
* Failed to find any suitable CPU.
* The task will never come back!
*/
BUG_ON(dl_bandwidth_enabled());
@@ -597,19 +594,18 @@ static inline void pull_dl_task(struct rq *rq)
{
}
static inline void queue_push_tasks(struct rq *rq)
static inline void deadline_queue_push_tasks(struct rq *rq)
{
}
static inline void queue_pull_task(struct rq *rq)
static inline void deadline_queue_pull_task(struct rq *rq)
{
}
#endif /* CONFIG_SMP */
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);
static void check_preempt_curr_dl(struct rq *rq, struct task_struct *p,
int flags);
static void check_preempt_curr_dl(struct rq *rq, struct task_struct *p, int flags);
/*
* We are being explicitly informed that a new instance is starting,
@@ -1763,7 +1759,7 @@ pick_next_task_dl(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
if (hrtick_enabled(rq))
start_hrtick_dl(rq, p);
queue_push_tasks(rq);
deadline_queue_push_tasks(rq);
return p;
}
@@ -1776,6 +1772,14 @@ static void put_prev_task_dl(struct rq *rq, struct task_struct *p)
enqueue_pushable_dl_task(rq, p);
}
/*
* scheduler tick hitting a task of our scheduling class.
*
* NOTE: This function can be called remotely by the tick offload that
* goes along full dynticks. Therefore no local assumption can be made
* and everything must be accessed through the @rq and @curr passed in
* parameters.
*/
static void task_tick_dl(struct rq *rq, struct task_struct *p, int queued)
{
update_curr_dl(rq);
@@ -1865,7 +1869,7 @@ static int find_later_rq(struct task_struct *task)
/*
* We have to consider system topology and task affinity
* first, then we can look for a suitable cpu.
* first, then we can look for a suitable CPU.
*/
if (!cpudl_find(&task_rq(task)->rd->cpudl, task, later_mask))
return -1;
@@ -1879,7 +1883,7 @@ static int find_later_rq(struct task_struct *task)
* Now we check how well this matches with task's
* affinity and system topology.
*
* The last cpu where the task run is our first
* The last CPU where the task run is our first
* guess, since it is most likely cache-hot there.
*/
if (cpumask_test_cpu(cpu, later_mask))
@@ -1909,9 +1913,9 @@ static int find_later_rq(struct task_struct *task)
best_cpu = cpumask_first_and(later_mask,
sched_domain_span(sd));
/*
* Last chance: if a cpu being in both later_mask
* Last chance: if a CPU being in both later_mask
* and current sd span is valid, that becomes our
* choice. Of course, the latest possible cpu is
* choice. Of course, the latest possible CPU is
* already under consideration through later_mask.
*/
if (best_cpu < nr_cpu_ids) {
@@ -2067,7 +2071,7 @@ retry:
if (task == next_task) {
/*
* The task is still there. We don't try
* again, some other cpu will pull it when ready.
* again, some other CPU will pull it when ready.
*/
goto out;
}
@@ -2300,12 +2304,12 @@ static void switched_from_dl(struct rq *rq, struct task_struct *p)
/*
* Since this might be the only -deadline task on the rq,
* this is the right place to try to pull some other one
* from an overloaded cpu, if any.
* from an overloaded CPU, if any.
*/
if (!task_on_rq_queued(p) || rq->dl.dl_nr_running)
return;
queue_pull_task(rq);
deadline_queue_pull_task(rq);
}
/*
@@ -2327,7 +2331,7 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p)
if (rq->curr != p) {
#ifdef CONFIG_SMP
if (p->nr_cpus_allowed > 1 && rq->dl.overloaded)
queue_push_tasks(rq);
deadline_queue_push_tasks(rq);
#endif
if (dl_task(rq->curr))
check_preempt_curr_dl(rq, p, 0);
@@ -2352,7 +2356,7 @@ static void prio_changed_dl(struct rq *rq, struct task_struct *p,
* or lowering its prio, so...
*/
if (!rq->dl.overloaded)
queue_pull_task(rq);
deadline_queue_pull_task(rq);
/*
* If we now have a earlier deadline task than p,
@@ -2626,17 +2630,17 @@ void __dl_clear_params(struct task_struct *p)
{
struct sched_dl_entity *dl_se = &p->dl;
dl_se->dl_runtime = 0;
dl_se->dl_deadline = 0;
dl_se->dl_period = 0;
dl_se->flags = 0;
dl_se->dl_bw = 0;
dl_se->dl_density = 0;
dl_se->dl_runtime = 0;
dl_se->dl_deadline = 0;
dl_se->dl_period = 0;
dl_se->flags = 0;
dl_se->dl_bw = 0;
dl_se->dl_density = 0;
dl_se->dl_throttled = 0;
dl_se->dl_yielded = 0;
dl_se->dl_non_contending = 0;
dl_se->dl_overrun = 0;
dl_se->dl_throttled = 0;
dl_se->dl_yielded = 0;
dl_se->dl_non_contending = 0;
dl_se->dl_overrun = 0;
}
bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr)
@@ -2655,21 +2659,22 @@ bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr)
#ifdef CONFIG_SMP
int dl_task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed)
{
unsigned int dest_cpu = cpumask_any_and(cpu_active_mask,
cs_cpus_allowed);
unsigned int dest_cpu;
struct dl_bw *dl_b;
bool overflow;
int cpus, ret;
unsigned long flags;
dest_cpu = cpumask_any_and(cpu_active_mask, cs_cpus_allowed);
rcu_read_lock_sched();
dl_b = dl_bw_of(dest_cpu);
raw_spin_lock_irqsave(&dl_b->lock, flags);
cpus = dl_bw_cpus(dest_cpu);
overflow = __dl_overflow(dl_b, cpus, 0, p->dl.dl_bw);
if (overflow)
if (overflow) {
ret = -EBUSY;
else {
} else {
/*
* We reserve space for this task in the destination
* root_domain, as we can't fail after this point.
@@ -2681,6 +2686,7 @@ int dl_task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allo
}
raw_spin_unlock_irqrestore(&dl_b->lock, flags);
rcu_read_unlock_sched();
return ret;
}
@@ -2701,6 +2707,7 @@ int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur,
ret = 0;
raw_spin_unlock_irqrestore(&cur_dl_b->lock, flags);
rcu_read_unlock_sched();
return ret;
}
@@ -2718,6 +2725,7 @@ bool dl_cpu_busy(unsigned int cpu)
overflow = __dl_overflow(dl_b, cpus, 0, 0);
raw_spin_unlock_irqrestore(&dl_b->lock, flags);
rcu_read_unlock_sched();
return overflow;
}
#endif

99
kernel/sched/debug.c
View File

@@ -1,7 +1,7 @@
/*
* kernel/sched/debug.c
*
* Print the CFS rbtree
* Print the CFS rbtree and other debugging details
*
* Copyright(C) 2007, Red Hat, Inc., Ingo Molnar
*
@@ -9,16 +9,6 @@
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/proc_fs.h>
#include <linux/sched/mm.h>
#include <linux/sched/task.h>
#include <linux/seq_file.h>
#include <linux/kallsyms.h>
#include <linux/utsname.h>
#include <linux/mempolicy.h>
#include <linux/debugfs.h>
#include "sched.h"
static DEFINE_SPINLOCK(sched_debug_lock);
@@ -274,34 +264,19 @@ sd_alloc_ctl_domain_table(struct sched_domain *sd)
if (table == NULL)
return NULL;
set_table_entry(&table[0], "min_interval", &sd->min_interval,
sizeof(long), 0644, proc_doulongvec_minmax, false);
set_table_entry(&table[1], "max_interval", &sd->max_interval,
sizeof(long), 0644, proc_doulongvec_minmax, false);
set_table_entry(&table[2], "busy_idx", &sd->busy_idx,
sizeof(int), 0644, proc_dointvec_minmax, true);
set_table_entry(&table[3], "idle_idx", &sd->idle_idx,
sizeof(int), 0644, proc_dointvec_minmax, true);
set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx,
sizeof(int), 0644, proc_dointvec_minmax, true);
set_table_entry(&table[5], "wake_idx", &sd->wake_idx,
sizeof(int), 0644, proc_dointvec_minmax, true);
set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx,
sizeof(int), 0644, proc_dointvec_minmax, true);
set_table_entry(&table[7], "busy_factor", &sd->busy_factor,
sizeof(int), 0644, proc_dointvec_minmax, false);
set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
sizeof(int), 0644, proc_dointvec_minmax, false);
set_table_entry(&table[9], "cache_nice_tries",
&sd->cache_nice_tries,
sizeof(int), 0644, proc_dointvec_minmax, false);
set_table_entry(&table[10], "flags", &sd->flags,
sizeof(int), 0644, proc_dointvec_minmax, false);
set_table_entry(&table[11], "max_newidle_lb_cost",
&sd->max_newidle_lb_cost,
sizeof(long), 0644, proc_doulongvec_minmax, false);
set_table_entry(&table[12], "name", sd->name,
CORENAME_MAX_SIZE, 0444, proc_dostring, false);
set_table_entry(&table[0] , "min_interval", &sd->min_interval, sizeof(long), 0644, proc_doulongvec_minmax, false);
set_table_entry(&table[1] , "max_interval", &sd->max_interval, sizeof(long), 0644, proc_doulongvec_minmax, false);
set_table_entry(&table[2] , "busy_idx", &sd->busy_idx, sizeof(int) , 0644, proc_dointvec_minmax, true );
set_table_entry(&table[3] , "idle_idx", &sd->idle_idx, sizeof(int) , 0644, proc_dointvec_minmax, true );
set_table_entry(&table[4] , "newidle_idx", &sd->newidle_idx, sizeof(int) , 0644, proc_dointvec_minmax, true );
set_table_entry(&table[5] , "wake_idx", &sd->wake_idx, sizeof(int) , 0644, proc_dointvec_minmax, true );
set_table_entry(&table[6] , "forkexec_idx", &sd->forkexec_idx, sizeof(int) , 0644, proc_dointvec_minmax, true );
set_table_entry(&table[7] , "busy_factor", &sd->busy_factor, sizeof(int) , 0644, proc_dointvec_minmax, false);
set_table_entry(&table[8] , "imbalance_pct", &sd->imbalance_pct, sizeof(int) , 0644, proc_dointvec_minmax, false);
set_table_entry(&table[9] , "cache_nice_tries", &sd->cache_nice_tries, sizeof(int) , 0644, proc_dointvec_minmax, false);
set_table_entry(&table[10], "flags", &sd->flags, sizeof(int) , 0644, proc_dointvec_minmax, false);
set_table_entry(&table[11], "max_newidle_lb_cost", &sd->max_newidle_lb_cost, sizeof(long), 0644, proc_doulongvec_minmax, false);
set_table_entry(&table[12], "name", sd->name, CORENAME_MAX_SIZE, 0444, proc_dostring, false);
/* &table[13] is terminator */
return table;
@@ -332,8 +307,8 @@ static struct ctl_table *sd_alloc_ctl_cpu_table(int cpu)
return table;
}
static cpumask_var_t sd_sysctl_cpus;
static struct ctl_table_header *sd_sysctl_header;
static cpumask_var_t sd_sysctl_cpus;
static struct ctl_table_header *sd_sysctl_header;
void register_sched_domain_sysctl(void)
{
@@ -413,14 +388,10 @@ 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 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 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 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)))
if (!se)
return;
@@ -428,6 +399,7 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group
PN(se->exec_start);
PN(se->vruntime);
PN(se->sum_exec_runtime);
if (schedstat_enabled()) {
PN_SCHEDSTAT(se->statistics.wait_start);
PN_SCHEDSTAT(se->statistics.sleep_start);
@@ -440,6 +412,7 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group
PN_SCHEDSTAT(se->statistics.wait_sum);
P_SCHEDSTAT(se->statistics.wait_count);
}
P(se->load.weight);
P(se->runnable_weight);
#ifdef CONFIG_SMP
@@ -464,6 +437,7 @@ static char *task_group_path(struct task_group *tg)
return group_path;
cgroup_path(tg->css.cgroup, group_path, PATH_MAX);
return group_path;
}
#endif
@@ -804,9 +778,9 @@ void sysrq_sched_debug_show(void)
/*
* This itererator needs some explanation.
* It returns 1 for the header position.
* This means 2 is cpu 0.
* In a hotplugged system some cpus, including cpu 0, may be missing so we have
* to use cpumask_* to iterate over the cpus.
* This means 2 is CPU 0.
* In a hotplugged system some CPUs, including CPU 0, may be missing so we have
* to use cpumask_* to iterate over the CPUs.
*/
static void *sched_debug_start(struct seq_file *file, loff_t *offset)
{
@@ -826,6 +800,7 @@ static void *sched_debug_start(struct seq_file *file, loff_t *offset)
if (n < nr_cpu_ids)
return (void *)(unsigned long)(n + 2);
return NULL;
}
@@ -840,10 +815,10 @@ static void sched_debug_stop(struct seq_file *file, void *data)
}
static const struct seq_operations sched_debug_sops = {
.start = sched_debug_start,
.next = sched_debug_next,
.stop = sched_debug_stop,
.show = sched_debug_show,
.start = sched_debug_start,
.next = sched_debug_next,
.stop = sched_debug_stop,
.show = sched_debug_show,
};
static int sched_debug_release(struct inode *inode, struct file *file)
@@ -881,14 +856,10 @@ static int __init init_sched_debug_procfs(void)
__initcall(init_sched_debug_procfs);
#define __P(F) \
SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)F)
#define P(F) \
SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)p->F)
#define __PN(F) \
SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
#define PN(F) \
SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))
#define __P(F) SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)F)
#define P(F) SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)p->F)
#define __PN(F) SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
#define PN(F) SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))
#ifdef CONFIG_NUMA_BALANCING

301
kernel/sched/fair.c
View File

@@ -20,25 +20,10 @@
* Adaptive scheduling granularity, math enhancements by Peter Zijlstra
* Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
*/
#include <linux/sched/mm.h>
#include <linux/sched/topology.h>
#include <linux/latencytop.h>
#include <linux/cpumask.h>
#include <linux/cpuidle.h>
#include <linux/slab.h>
#include <linux/profile.h>
#include <linux/interrupt.h>
#include <linux/mempolicy.h>
#include <linux/migrate.h>
#include <linux/task_work.h>
#include <linux/sched/isolation.h>
#include "sched.h"
#include <trace/events/sched.h>
#include "sched.h"
/*
* Targeted preemption latency for CPU-bound tasks:
*
@@ -103,7 +88,7 @@ const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
#ifdef CONFIG_SMP
/*
* For asym packing, by default the lower numbered cpu has higher priority.
* For asym packing, by default the lower numbered CPU has higher priority.
*/
int __weak arch_asym_cpu_priority(int cpu)
{
@@ -1181,7 +1166,7 @@ pid_t task_numa_group_id(struct task_struct *p)
}
/*
* The averaged statistics, shared & private, memory & cpu,
* The averaged statistics, shared & private, memory & CPU,
* occupy the first half of the array. The second half of the
* array is for current counters, which are averaged into the
* first set by task_numa_placement.
@@ -1587,7 +1572,7 @@ static void task_numa_compare(struct task_numa_env *env,
* be incurred if the tasks were swapped.
*/
if (cur) {
/* Skip this swap candidate if cannot move to the source cpu */
/* Skip this swap candidate if cannot move to the source CPU: */
if (!cpumask_test_cpu(env->src_cpu, &cur->cpus_allowed))
goto unlock;
@@ -1631,7 +1616,7 @@ static void task_numa_compare(struct task_numa_env *env,
goto balance;
}
/* Balance doesn't matter much if we're running a task per cpu */
/* Balance doesn't matter much if we're running a task per CPU: */
if (imp > env->best_imp && src_rq->nr_running == 1 &&
dst_rq->nr_running == 1)
goto assign;
@@ -1676,7 +1661,7 @@ balance:
*/
if (!cur) {
/*
* select_idle_siblings() uses an per-cpu cpumask that
* select_idle_siblings() uses an per-CPU cpumask that
* can be used from IRQ context.
*/
local_irq_disable();
@@ -1869,6 +1854,7 @@ static int task_numa_migrate(struct task_struct *p)
static void numa_migrate_preferred(struct task_struct *p)
{
unsigned long interval = HZ;
unsigned long numa_migrate_retry;
/* This task has no NUMA fault statistics yet */
if (unlikely(p->numa_preferred_nid == -1 || !p->numa_faults))
@@ -1876,7 +1862,18 @@ static void numa_migrate_preferred(struct task_struct *p)
/* Periodically retry migrating the task to the preferred node */
interval = min(interval, msecs_to_jiffies(p->numa_scan_period) / 16);
p->numa_migrate_retry = jiffies + interval;
numa_migrate_retry = jiffies + interval;
/*
* Check that the new retry threshold is after the current one. If
* the retry is in the future, it implies that wake_affine has
* temporarily asked NUMA balancing to backoff from placement.
*/
if (numa_migrate_retry > p->numa_migrate_retry)
return;
/* Safe to try placing the task on the preferred node */
p->numa_migrate_retry = numa_migrate_retry;
/* Success if task is already running on preferred CPU */
if (task_node(p) == p->numa_preferred_nid)
@@ -2823,7 +2820,7 @@ void reweight_task(struct task_struct *p, int prio)
}
#ifdef CONFIG_FAIR_GROUP_SCHED
# ifdef CONFIG_SMP
#ifdef CONFIG_SMP
/*
* All this does is approximate the hierarchical proportion which includes that
* global sum we all love to hate.
@@ -2974,7 +2971,7 @@ static long calc_group_runnable(struct cfs_rq *cfs_rq, long shares)
return clamp_t(long, runnable, MIN_SHARES, shares);
}
# endif /* CONFIG_SMP */
#endif /* CONFIG_SMP */
static inline int throttled_hierarchy(struct cfs_rq *cfs_rq);
@@ -3350,7 +3347,7 @@ static inline void update_tg_load_avg(struct cfs_rq *cfs_rq, int force)
}
/*
* Called within set_task_rq() right before setting a task's cpu. The
* Called within set_task_rq() right before setting a task's CPU. The
* caller only guarantees p->pi_lock is held; no other assumptions,
* including the state of rq->lock, should be made.
*/
@@ -3529,7 +3526,7 @@ update_tg_cfs_runnable(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cf
/*
* runnable_sum can't be lower than running_sum
* As running sum is scale with cpu capacity wehreas the runnable sum
* As running sum is scale with CPU capacity wehreas the runnable sum
* is not we rescale running_sum 1st
*/
running_sum = se->avg.util_sum /
@@ -4676,7 +4673,7 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
if (!se)
add_nr_running(rq, task_delta);
/* determine whether we need to wake up potentially idle cpu */
/* Determine whether we need to wake up potentially idle CPU: */
if (rq->curr == rq->idle && rq->cfs.nr_running)
resched_curr(rq);
}
@@ -5041,7 +5038,7 @@ static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
}
/*
* Both these cpu hotplug callbacks race against unregister_fair_sched_group()
* Both these CPU hotplug callbacks race against unregister_fair_sched_group()
*
* The race is harmless, since modifying bandwidth settings of unhooked group
* bits doesn't do much.
@@ -5086,7 +5083,7 @@ static void __maybe_unused unthrottle_offline_cfs_rqs(struct rq *rq)
*/
cfs_rq->runtime_remaining = 1;
/*
* Offline rq is schedulable till cpu is completely disabled
* Offline rq is schedulable till CPU is completely disabled
* in take_cpu_down(), so we prevent new cfs throttling here.
*/
cfs_rq->runtime_enabled = 0;
@@ -5323,8 +5320,8 @@ DEFINE_PER_CPU(cpumask_var_t, select_idle_mask);
*
* load' = (1 - 1/2^i) * load + (1/2^i) * cur_load
*
* If a cpu misses updates for n ticks (as it was idle) and update gets
* called on the n+1-th tick when cpu may be busy, then we have:
* If a CPU misses updates for n ticks (as it was idle) and update gets
* called on the n+1-th tick when CPU may be busy, then we have:
*
* load_n = (1 - 1/2^i)^n * load_0
* load_n+1 = (1 - 1/2^i) * load_n + (1/2^i) * cur_load
@@ -5468,7 +5465,7 @@ static unsigned long weighted_cpuload(struct rq *rq)
#ifdef CONFIG_NO_HZ_COMMON
/*
* There is no sane way to deal with nohz on smp when using jiffies because the
* cpu doing the jiffies update might drift wrt the cpu doing the jiffy reading
* CPU doing the jiffies update might drift wrt the CPU doing the jiffy reading
* causing off-by-one errors in observed deltas; {0,2} instead of {1,1}.
*
* Therefore we need to avoid the delta approach from the regular tick when
@@ -5579,7 +5576,7 @@ void cpu_load_update_active(struct rq *this_rq)
}
/*
* Return a low guess at the load of a migration-source cpu weighted
* Return a low guess at the load of a migration-source CPU weighted
* according to the scheduling class and "nice" value.
*
* We want to under-estimate the load of migration sources, to
@@ -5597,7 +5594,7 @@ static unsigned long source_load(int cpu, int type)
}
/*
* Return a high guess at the load of a migration-target cpu weighted
* Return a high guess at the load of a migration-target CPU weighted
* according to the scheduling class and "nice" value.
*/
static unsigned long target_load(int cpu, int type)
@@ -5724,7 +5721,6 @@ wake_affine_weight(struct sched_domain *sd, struct task_struct *p,
unsigned long task_load;
this_eff_load = target_load(this_cpu, sd->wake_idx);
prev_eff_load = source_load(prev_cpu, sd->wake_idx);
if (sync) {
unsigned long current_load = task_h_load(current);
@@ -5742,18 +5738,69 @@ wake_affine_weight(struct sched_domain *sd, struct task_struct *p,
this_eff_load *= 100;
this_eff_load *= capacity_of(prev_cpu);
prev_eff_load = source_load(prev_cpu, sd->wake_idx);
prev_eff_load -= task_load;
if (sched_feat(WA_BIAS))
prev_eff_load *= 100 + (sd->imbalance_pct - 100) / 2;
prev_eff_load *= capacity_of(this_cpu);
return this_eff_load <= prev_eff_load ? this_cpu : nr_cpumask_bits;
/*
* If sync, adjust the weight of prev_eff_load such that if
* prev_eff == this_eff that select_idle_sibling() will consider
* stacking the wakee on top of the waker if no other CPU is
* idle.
*/
if (sync)
prev_eff_load += 1;
return this_eff_load < prev_eff_load ? this_cpu : nr_cpumask_bits;
}
static int wake_affine(struct sched_domain *sd, struct task_struct *p,
int prev_cpu, int sync)
#ifdef CONFIG_NUMA_BALANCING
static void
update_wa_numa_placement(struct task_struct *p, int prev_cpu, int target)
{
unsigned long interval;
if (!static_branch_likely(&sched_numa_balancing))
return;
/* If balancing has no preference then continue gathering data */
if (p->numa_preferred_nid == -1)
return;
/*
* If the wakeup is not affecting locality then it is neutral from
* the perspective of NUMA balacing so continue gathering data.
*/
if (cpu_to_node(prev_cpu) == cpu_to_node(target))
return;
/*
* Temporarily prevent NUMA balancing trying to place waker/wakee after
* wakee has been moved by wake_affine. This will potentially allow
* related tasks to converge and update their data placement. The
* 4 * numa_scan_period is to allow the two-pass filter to migrate
* hot data to the wakers node.
*/
interval = max(sysctl_numa_balancing_scan_delay,
p->numa_scan_period << 2);
p->numa_migrate_retry = jiffies + msecs_to_jiffies(interval);
interval = max(sysctl_numa_balancing_scan_delay,
current->numa_scan_period << 2);
current->numa_migrate_retry = jiffies + msecs_to_jiffies(interval);
}
#else
static void
update_wa_numa_placement(struct task_struct *p, int prev_cpu, int target)
{
}
#endif
static int wake_affine(struct sched_domain *sd, struct task_struct *p,
int this_cpu, int prev_cpu, int sync)
{
int this_cpu = smp_processor_id();
int target = nr_cpumask_bits;
if (sched_feat(WA_IDLE))
@@ -5766,6 +5813,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p,
if (target == nr_cpumask_bits)
return prev_cpu;
update_wa_numa_placement(p, prev_cpu, target);
schedstat_inc(sd->ttwu_move_affine);
schedstat_inc(p->se.statistics.nr_wakeups_affine);
return target;
@@ -5826,7 +5874,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
max_spare_cap = 0;
for_each_cpu(i, sched_group_span(group)) {
/* Bias balancing toward cpus of our domain */
/* Bias balancing toward CPUs of our domain */
if (local_group)
load = source_load(i, load_idx);
else
@@ -5856,7 +5904,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
if (min_runnable_load > (runnable_load + imbalance)) {
/*
* The runnable load is significantly smaller
* so we can pick this new cpu
* so we can pick this new CPU:
*/
min_runnable_load = runnable_load;
min_avg_load = avg_load;
@@ -5865,7 +5913,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
(100*min_avg_load > imbalance_scale*avg_load)) {
/*
* The runnable loads are close so take the
* blocked load into account through avg_load.
* blocked load into account through avg_load:
*/
min_avg_load = avg_load;
idlest = group;
@@ -5903,6 +5951,18 @@ skip_spare:
if (!idlest)
return NULL;
/*
* When comparing groups across NUMA domains, it's possible for the
* local domain to be very lightly loaded relative to the remote
* domains but "imbalance" skews the comparison making remote CPUs
* look much more favourable. When considering cross-domain, add
* imbalance to the runnable load on the remote node and consider
* staying local.
*/
if ((sd->flags & SD_NUMA) &&
min_runnable_load + imbalance >= this_runnable_load)
return NULL;
if (min_runnable_load > (this_runnable_load + imbalance))
return NULL;
@@ -5914,7 +5974,7 @@ skip_spare:
}
/*
* find_idlest_group_cpu - find the idlest cpu among the cpus in group.
* find_idlest_group_cpu - find the idlest CPU among the CPUs in the group.
*/
static int
find_idlest_group_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
@@ -5992,12 +6052,12 @@ static inline int find_idlest_cpu(struct sched_domain *sd, struct task_struct *p
new_cpu = find_idlest_group_cpu(group, p, cpu);
if (new_cpu == cpu) {
/* Now try balancing at a lower domain level of cpu */
/* Now try balancing at a lower domain level of 'cpu': */
sd = sd->child;
continue;
}
/* Now try balancing at a lower domain level of new_cpu */
/* Now try balancing at a lower domain level of 'new_cpu': */
cpu = new_cpu;
weight = sd->span_weight;
sd = NULL;
@@ -6007,7 +6067,6 @@ static inline int find_idlest_cpu(struct sched_domain *sd, struct task_struct *p
if (tmp->flags & sd_flag)
sd = tmp;
}
/* while loop will break here if sd == NULL */
}
return new_cpu;
@@ -6203,12 +6262,12 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target)
return target;
/*
* If the previous cpu is cache affine and idle, don't be stupid.
* If the previous CPU is cache affine and idle, don't be stupid:
*/
if (prev != target && cpus_share_cache(prev, target) && idle_cpu(prev))
return prev;
/* Check a recently used CPU as a potential idle candidate */
/* Check a recently used CPU as a potential idle candidate: */
recent_used_cpu = p->recent_used_cpu;
if (recent_used_cpu != prev &&
recent_used_cpu != target &&
@@ -6217,7 +6276,7 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target)
cpumask_test_cpu(p->recent_used_cpu, &p->cpus_allowed)) {
/*
* Replace recent_used_cpu with prev as it is a potential
* candidate for the next wake.
* candidate for the next wake:
*/
p->recent_used_cpu = prev;
return recent_used_cpu;
@@ -6282,7 +6341,7 @@ static inline unsigned long task_util(struct task_struct *p)
}
/*
* cpu_util_wake: Compute cpu utilization with any contributions from
* cpu_util_wake: Compute CPU utilization with any contributions from
* the waking task p removed.
*/
static unsigned long cpu_util_wake(int cpu, struct task_struct *p)
@@ -6328,10 +6387,10 @@ static int wake_cap(struct task_struct *p, int cpu, int prev_cpu)
* that have the 'sd_flag' flag set. In practice, this is SD_BALANCE_WAKE,
* SD_BALANCE_FORK, or SD_BALANCE_EXEC.
*
* Balances load by selecting the idlest cpu in the idlest group, or under
* certain conditions an idle sibling cpu if the domain has SD_WAKE_AFFINE set.
* Balances load by selecting the idlest CPU in the idlest group, or under
* certain conditions an idle sibling CPU if the domain has SD_WAKE_AFFINE set.
*
* Returns the target cpu number.
* Returns the target CPU number.
*
* preempt must be disabled.
*/
@@ -6342,7 +6401,7 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f
int cpu = smp_processor_id();
int new_cpu = prev_cpu;
int want_affine = 0;
int sync = wake_flags & WF_SYNC;
int sync = (wake_flags & WF_SYNC) && !(current->flags & PF_EXITING);
if (sd_flag & SD_BALANCE_WAKE) {
record_wakee(p);
@@ -6356,7 +6415,7 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f
break;
/*
* If both cpu and prev_cpu are part of this domain,
* If both 'cpu' and 'prev_cpu' are part of this domain,
* cpu is a valid SD_WAKE_AFFINE target.
*/
if (want_affine && (tmp->flags & SD_WAKE_AFFINE) &&
@@ -6376,7 +6435,7 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f
if (cpu == prev_cpu)
goto pick_cpu;
new_cpu = wake_affine(affine_sd, p, prev_cpu, sync);
new_cpu = wake_affine(affine_sd, p, cpu, prev_cpu, sync);
}
if (sd && !(sd_flag & SD_BALANCE_FORK)) {
@@ -6407,9 +6466,9 @@ pick_cpu:
static void detach_entity_cfs_rq(struct sched_entity *se);
/*
* Called immediately before a task is migrated to a new cpu; task_cpu(p) and
* Called immediately before a task is migrated to a new CPU; task_cpu(p) and
* cfs_rq_of(p) references at time of call are still valid and identify the
* previous cpu. The caller guarantees p->pi_lock or task_rq(p)->lock is held.
* previous CPU. The caller guarantees p->pi_lock or task_rq(p)->lock is held.
*/
static void migrate_task_rq_fair(struct task_struct *p)
{
@@ -6843,17 +6902,17 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preemp
* BASICS
*
* The purpose of load-balancing is to achieve the same basic fairness the
* per-cpu scheduler provides, namely provide a proportional amount of compute
* per-CPU scheduler provides, namely provide a proportional amount of compute
* time to each task. This is expressed in the following equation:
*
* W_i,n/P_i == W_j,n/P_j for all i,j (1)
*
* Where W_i,n is the n-th weight average for cpu i. The instantaneous weight
* Where W_i,n is the n-th weight average for CPU i. The instantaneous weight
* W_i,0 is defined as:
*
* W_i,0 = \Sum_j w_i,j (2)
*
* Where w_i,j is the weight of the j-th runnable task on cpu i. This weight
* Where w_i,j is the weight of the j-th runnable task on CPU i. This weight
* is derived from the nice value as per sched_prio_to_weight[].
*
* The weight average is an exponential decay average of the instantaneous
@@ -6861,7 +6920,7 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preemp
*
* W'_i,n = (2^n - 1) / 2^n * W_i,n + 1 / 2^n * W_i,0 (3)
*
* C_i is the compute capacity of cpu i, typically it is the
* C_i is the compute capacity of CPU i, typically it is the
* fraction of 'recent' time available for SCHED_OTHER task execution. But it
* can also include other factors [XXX].
*
@@ -6882,11 +6941,11 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preemp
* SCHED DOMAINS
*
* In order to solve the imbalance equation (4), and avoid the obvious O(n^2)
* for all i,j solution, we create a tree of cpus that follows the hardware
* for all i,j solution, we create a tree of CPUs that follows the hardware
* topology where each level pairs two lower groups (or better). This results
* in O(log n) layers. Furthermore we reduce the number of cpus going up the
* in O(log n) layers. Furthermore we reduce the number of CPUs going up the
* tree to only the first of the previous level and we decrease the frequency
* of load-balance at each level inv. proportional to the number of cpus in
* of load-balance at each level inv. proportional to the number of CPUs in
* the groups.
*
* This yields:
@@ -6895,7 +6954,7 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preemp
* \Sum { --- * --- * 2^i } = O(n) (5)
* i = 0 2^i 2^i
* `- size of each group
* | | `- number of cpus doing load-balance
* | | `- number of CPUs doing load-balance
* | `- freq
* `- sum over all levels
*
@@ -6903,7 +6962,7 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preemp
* this makes (5) the runtime complexity of the balancer.
*
* An important property here is that each CPU is still (indirectly) connected
* to every other cpu in at most O(log n) steps:
* to every other CPU in at most O(log n) steps:
*
* The adjacency matrix of the resulting graph is given by:
*
@@ -6915,7 +6974,7 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preemp
*
* A^(log_2 n)_i,j != 0 for all i,j (7)
*
* Showing there's indeed a path between every cpu in at most O(log n) steps.
* Showing there's indeed a path between every CPU in at most O(log n) steps.
* The task movement gives a factor of O(m), giving a convergence complexity
* of:
*
@@ -6925,7 +6984,7 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preemp
* WORK CONSERVING
*
* In order to avoid CPUs going idle while there's still work to do, new idle
* balancing is more aggressive and has the newly idle cpu iterate up the domain
* balancing is more aggressive and has the newly idle CPU iterate up the domain
* tree itself instead of relying on other CPUs to bring it work.
*
* This adds some complexity to both (5) and (8) but it reduces the total idle
@@ -6946,7 +7005,7 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preemp
*
* s_k,i = \Sum_j w_i,j,k and S_k = \Sum_i s_k,i (10)
*
* w_i,j,k is the weight of the j-th runnable task in the k-th cgroup on cpu i.
* w_i,j,k is the weight of the j-th runnable task in the k-th cgroup on CPU i.
*
* The big problem is S_k, its a global sum needed to compute a local (W_i)
* property.
@@ -7110,7 +7169,7 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env)
env->flags |= LBF_SOME_PINNED;
/*
* Remember if this task can be migrated to any other cpu in
* Remember if this task can be migrated to any other CPU in
* our sched_group. We may want to revisit it if we couldn't
* meet load balance goals by pulling other tasks on src_cpu.
*
@@ -7120,7 +7179,7 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env)
if (env->idle == CPU_NEWLY_IDLE || (env->flags & LBF_DST_PINNED))
return 0;
/* Prevent to re-select dst_cpu via env's cpus */
/* Prevent to re-select dst_cpu via env's CPUs: */
for_each_cpu_and(cpu, env->dst_grpmask, env->cpus) {
if (cpumask_test_cpu(cpu, &p->cpus_allowed)) {
env->flags |= LBF_DST_PINNED;
@@ -7694,8 +7753,8 @@ check_cpu_capacity(struct rq *rq, struct sched_domain *sd)
* Group imbalance indicates (and tries to solve) the problem where balancing
* groups is inadequate due to ->cpus_allowed constraints.
*
* Imagine a situation of two groups of 4 cpus each and 4 tasks each with a
* cpumask covering 1 cpu of the first group and 3 cpus of the second group.
* Imagine a situation of two groups of 4 CPUs each and 4 tasks each with a
* cpumask covering 1 CPU of the first group and 3 CPUs of the second group.
* Something like:
*
* { 0 1 2 3 } { 4 5 6 7 }
@@ -7703,7 +7762,7 @@ check_cpu_capacity(struct rq *rq, struct sched_domain *sd)
*
* If we were to balance group-wise we'd place two tasks in the first group and
* two tasks in the second group. Clearly this is undesired as it will overload
* cpu 3 and leave one of the cpus in the second group unused.
* cpu 3 and leave one of the CPUs in the second group unused.
*
* The current solution to this issue is detecting the skew in the first group
* by noticing the lower domain failed to reach balance and had difficulty
@@ -7816,7 +7875,7 @@ static inline void update_sg_lb_stats(struct lb_env *env,
for_each_cpu_and(i, sched_group_span(group), env->cpus) {
struct rq *rq = cpu_rq(i);
/* Bias balancing toward cpus of our domain */
/* Bias balancing toward CPUs of our domain: */
if (local_group)
load = target_load(i, load_idx);
else
@@ -7902,7 +7961,7 @@ asym_packing:
if (!(env->sd->flags & SD_ASYM_PACKING))
return true;
/* No ASYM_PACKING if target cpu is already busy */
/* No ASYM_PACKING if target CPU is already busy */
if (env->idle == CPU_NOT_IDLE)
return true;
/*
@@ -7915,7 +7974,7 @@ asym_packing:
if (!sds->busiest)
return true;
/* Prefer to move from lowest priority cpu's work */
/* Prefer to move from lowest priority CPU's work */
if (sched_asym_prefer(sds->busiest->asym_prefer_cpu,
sg->asym_prefer_cpu))
return true;
@@ -8168,7 +8227,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
if (busiest->group_type == group_imbalanced) {
/*
* In the group_imb case we cannot rely on group-wide averages
* to ensure cpu-load equilibrium, look at wider averages. XXX
* to ensure CPU-load equilibrium, look at wider averages. XXX
*/
busiest->load_per_task =
min(busiest->load_per_task, sds->avg_load);
@@ -8187,7 +8246,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
}
/*
* If there aren't any idle cpus, avoid creating some.
* If there aren't any idle CPUs, avoid creating some.
*/
if (busiest->group_type == group_overloaded &&
local->group_type == group_overloaded) {
@@ -8201,9 +8260,9 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
}
/*
* We're trying to get all the cpus to the average_load, so we don't
* We're trying to get all the CPUs to the average_load, so we don't
* want to push ourselves above the average load, nor do we wish to
* reduce the max loaded cpu below the average load. At the same time,
* reduce the max loaded CPU below the average load. At the same time,
* we also don't want to reduce the group load below the group
* capacity. Thus we look for the minimum possible imbalance.
*/
@@ -8297,9 +8356,9 @@ static struct sched_group *find_busiest_group(struct lb_env *env)
if (env->idle == CPU_IDLE) {
/*
* This cpu is idle. If the busiest group is not overloaded
* This CPU is idle. If the busiest group is not overloaded
* and there is no imbalance between this and busiest group
* wrt idle cpus, it is balanced. The imbalance becomes
* wrt idle CPUs, it is balanced. The imbalance becomes
* significant if the diff is greater than 1 otherwise we
* might end up to just move the imbalance on another group
*/
@@ -8327,7 +8386,7 @@ out_balanced:
}
/*
* find_busiest_queue - find the busiest runqueue among the cpus in group.
* find_busiest_queue - find the busiest runqueue among the CPUs in the group.
*/
static struct rq *find_busiest_queue(struct lb_env *env,
struct sched_group *group)
@@ -8371,7 +8430,7 @@ static struct rq *find_busiest_queue(struct lb_env *env,
/*
* When comparing with imbalance, use weighted_cpuload()
* which is not scaled with the cpu capacity.
* which is not scaled with the CPU capacity.
*/
if (rq->nr_running == 1 && wl > env->imbalance &&
@@ -8379,9 +8438,9 @@ static struct rq *find_busiest_queue(struct lb_env *env,
continue;
/*
* For the load comparisons with the other cpu's, consider
* the weighted_cpuload() scaled with the cpu capacity, so
* that the load can be moved away from the cpu that is
* For the load comparisons with the other CPU's, consider
* the weighted_cpuload() scaled with the CPU capacity, so
* that the load can be moved away from the CPU that is
* potentially running at a lower capacity.
*
* Thus we're looking for max(wl_i / capacity_i), crosswise
@@ -8452,13 +8511,13 @@ static int should_we_balance(struct lb_env *env)
return 0;
/*
* In the newly idle case, we will allow all the cpu's
* In the newly idle case, we will allow all the CPUs
* to do the newly idle load balance.
*/
if (env->idle == CPU_NEWLY_IDLE)
return 1;
/* Try to find first idle cpu */
/* Try to find first idle CPU */
for_each_cpu_and(cpu, group_balance_mask(sg), env->cpus) {
if (!idle_cpu(cpu))
continue;
@@ -8471,7 +8530,7 @@ static int should_we_balance(struct lb_env *env)
balance_cpu = group_balance_cpu(sg);
/*
* First idle cpu or the first cpu(busiest) in this sched group
* First idle CPU or the first CPU(busiest) in this sched group
* is eligible for doing load balancing at this and above domains.
*/
return balance_cpu == env->dst_cpu;
@@ -8580,7 +8639,7 @@ more_balance:
* Revisit (affine) tasks on src_cpu that couldn't be moved to
* us and move them to an alternate dst_cpu in our sched_group
* where they can run. The upper limit on how many times we
* iterate on same src_cpu is dependent on number of cpus in our
* iterate on same src_cpu is dependent on number of CPUs in our
* sched_group.
*
* This changes load balance semantics a bit on who can move
@@ -8597,7 +8656,7 @@ more_balance:
*/
if ((env.flags & LBF_DST_PINNED) && env.imbalance > 0) {
/* Prevent to re-select dst_cpu via env's cpus */
/* Prevent to re-select dst_cpu via env's CPUs */
cpumask_clear_cpu(env.dst_cpu, env.cpus);
env.dst_rq = cpu_rq(env.new_dst_cpu);
@@ -8659,9 +8718,10 @@ more_balance:
raw_spin_lock_irqsave(&busiest->lock, flags);
/* don't kick the active_load_balance_cpu_stop,
* if the curr task on busiest cpu can't be
* moved to this_cpu
/*
* Don't kick the active_load_balance_cpu_stop,
* if the curr task on busiest CPU can't be
* moved to this_cpu:
*/
if (!cpumask_test_cpu(this_cpu, &busiest->curr->cpus_allowed)) {
raw_spin_unlock_irqrestore(&busiest->lock,
@@ -8887,7 +8947,7 @@ out:
}
/*
* active_load_balance_cpu_stop is run by cpu stopper. It pushes
* active_load_balance_cpu_stop is run by the CPU stopper. It pushes
* running tasks off the busiest CPU onto idle CPUs. It requires at
* least 1 task to be running on each physical CPU where possible, and
* avoids physical / logical imbalances.
@@ -8911,7 +8971,7 @@ static int active_load_balance_cpu_stop(void *data)
if (!cpu_active(busiest_cpu) || !cpu_active(target_cpu))
goto out_unlock;
/* make sure the requested cpu hasn't gone down in the meantime */
/* Make sure the requested CPU hasn't gone down in the meantime: */
if (unlikely(busiest_cpu != smp_processor_id() ||
!busiest_rq->active_balance))
goto out_unlock;
@@ -8923,7 +8983,7 @@ static int active_load_balance_cpu_stop(void *data)
/*
* This condition is "impossible", if it occurs
* we need to fix it. Originally reported by
* Bjorn Helgaas on a 128-cpu setup.
* Bjorn Helgaas on a 128-CPU setup.
*/
BUG_ON(busiest_rq == target_rq);
@@ -9025,7 +9085,7 @@ static void nohz_balancer_kick(void)
return;
/*
* Use smp_send_reschedule() instead of resched_cpu().
* This way we generate a sched IPI on the target cpu which
* This way we generate a sched IPI on the target CPU which
* is idle. And the softirq performing nohz idle load balance
* will be run before returning from the IPI.
*/
@@ -9082,14 +9142,12 @@ unlock:
}
/*
* This routine will record that the cpu is going idle with tick stopped.
* This routine will record that the CPU is going idle with tick stopped.
* This info will be used in performing idle load balancing in the future.
*/
void nohz_balance_enter_idle(int cpu)
{
/*
* If this cpu is going down, then nothing needs to be done.
*/
/* If this CPU is going down, then nothing needs to be done: */
if (!cpu_active(cpu))
return;
@@ -9100,9 +9158,7 @@ void nohz_balance_enter_idle(int cpu)
if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
return;
/*
* If we're a completely isolated CPU, we don't play.
*/
/* If we're a completely isolated CPU, we don't play: */
if (on_null_domain(cpu_rq(cpu)))
return;
@@ -9211,7 +9267,7 @@ out:
/*
* next_balance will be updated only when there is a need.
* When the cpu is attached to null domain for ex, it will not be
* When the CPU is attached to null domain for ex, it will not be
* updated.
*/
if (likely(update_next_balance)) {
@@ -9235,7 +9291,7 @@ out:
#ifdef CONFIG_NO_HZ_COMMON
/*
* In CONFIG_NO_HZ_COMMON case, the idle balance kickee will do the
* rebalancing for all the cpus for whom scheduler ticks are stopped.
* rebalancing for all the CPUs for whom scheduler ticks are stopped.
*/
static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle)
{
@@ -9255,8 +9311,8 @@ static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle)
continue;
/*
* If this cpu gets work to do, stop the load balancing
* work being done for other cpus. Next load
* If this CPU gets work to do, stop the load balancing
* work being done for other CPUs. Next load
* balancing owner will pick it up.
*/
if (need_resched())
@@ -9298,13 +9354,13 @@ end:
/*
* Current heuristic for kicking the idle load balancer in the presence
* of an idle cpu in the system.
* of an idle CPU in the system.
* - This rq has more than one task.
* - This rq has at least one CFS task and the capacity of the CPU is
* significantly reduced because of RT tasks or IRQs.
* - At parent of LLC scheduler domain level, this cpu's scheduler group has
* multiple busy cpu.
* - For SD_ASYM_PACKING, if the lower numbered cpu's in the scheduler
* - At parent of LLC scheduler domain level, this CPU's scheduler group has
* multiple busy CPUs.
* - For SD_ASYM_PACKING, if the lower numbered CPU's in the scheduler
* domain span are idle.
*/
static inline bool nohz_kick_needed(struct rq *rq)
@@ -9394,10 +9450,10 @@ static __latent_entropy void run_rebalance_domains(struct softirq_action *h)
CPU_IDLE : CPU_NOT_IDLE;
/*
* If this cpu has a pending nohz_balance_kick, then do the
* balancing on behalf of the other idle cpus whose ticks are
* If this CPU has a pending nohz_balance_kick, then do the
* balancing on behalf of the other idle CPUs whose ticks are
* stopped. Do nohz_idle_balance *before* rebalance_domains to
* give the idle cpus a chance to load balance. Else we may
* give the idle CPUs a chance to load balance. Else we may
* load balance only within the local sched_domain hierarchy
* and abort nohz_idle_balance altogether if we pull some load.
*/
@@ -9440,7 +9496,12 @@ static void rq_offline_fair(struct rq *rq)
#endif /* CONFIG_SMP */
/*
* scheduler tick hitting a task of our scheduling class:
* scheduler tick hitting a task of our scheduling class.
*
* NOTE: This function can be called remotely by the tick offload that
* goes along full dynticks. Therefore no local assumption can be made
* and everything must be accessed through the @rq and @curr passed in
* parameters.
*/
static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
{

142
kernel/sched/idle.c
View File

@@ -1,23 +1,14 @@
/*
* Generic entry point for the idle threads
* Generic entry points for the idle threads and
* implementation of the idle task scheduling class.
*
* (NOTE: these are not related to SCHED_IDLE batch scheduled
* tasks which are handled in sched/fair.c )
*/
#include <linux/sched.h>
#include <linux/sched/idle.h>
#include <linux/cpu.h>
#include <linux/cpuidle.h>
#include <linux/cpuhotplug.h>
#include <linux/tick.h>
#include <linux/mm.h>
#include <linux/stackprotector.h>
#include <linux/suspend.h>
#include <linux/livepatch.h>
#include <asm/tlb.h>
#include "sched.h"
#include <trace/events/power.h>
#include "sched.h"
/* Linker adds these: start and end of __cpuidle functions */
extern char __cpuidle_text_start[], __cpuidle_text_end[];
@@ -46,6 +37,7 @@ void cpu_idle_poll_ctrl(bool enable)
static int __init cpu_idle_poll_setup(char *__unused)
{
cpu_idle_force_poll = 1;
return 1;
}
__setup("nohlt", cpu_idle_poll_setup);
@@ -53,6 +45,7 @@ __setup("nohlt", cpu_idle_poll_setup);
static int __init cpu_idle_nopoll_setup(char *__unused)
{
cpu_idle_force_poll = 0;
return 1;
}
__setup("hlt", cpu_idle_nopoll_setup);
@@ -64,12 +57,14 @@ static noinline int __cpuidle cpu_idle_poll(void)
trace_cpu_idle_rcuidle(0, smp_processor_id());
local_irq_enable();
stop_critical_timings();
while (!tif_need_resched() &&
(cpu_idle_force_poll || tick_check_broadcast_expired()))
cpu_relax();
start_critical_timings();
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
rcu_idle_exit();
return 1;
}
@@ -332,8 +327,8 @@ void cpu_startup_entry(enum cpuhp_state state)
{
/*
* This #ifdef needs to die, but it's too late in the cycle to
* make this generic (arm and sh have never invoked the canary
* init for the non boot cpus!). Will be fixed in 3.11
* make this generic (ARM and SH have never invoked the canary
* init for the non boot CPUs!). Will be fixed in 3.11
*/
#ifdef CONFIG_X86
/*
@@ -350,3 +345,116 @@ void cpu_startup_entry(enum cpuhp_state state)
while (1)
do_idle();
}
/*
* idle-task scheduling class.
*/
#ifdef CONFIG_SMP
static int
select_task_rq_idle(struct task_struct *p, int cpu, int sd_flag, int flags)
{
return task_cpu(p); /* IDLE tasks as never migrated */
}
#endif
/*
* Idle tasks are unconditionally rescheduled:
*/
static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int flags)
{
resched_curr(rq);
}
static struct task_struct *
pick_next_task_idle(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
{
put_prev_task(rq, prev);
update_idle_core(rq);
schedstat_inc(rq->sched_goidle);
return rq->idle;
}
/*
* It is not legal to sleep in the idle task - print a warning
* message if some code attempts to do it:
*/
static void
dequeue_task_idle(struct rq *rq, struct task_struct *p, int flags)
{
raw_spin_unlock_irq(&rq->lock);
printk(KERN_ERR "bad: scheduling from the idle thread!\n");
dump_stack();
raw_spin_lock_irq(&rq->lock);
}
static void put_prev_task_idle(struct rq *rq, struct task_struct *prev)
{
}
/*
* scheduler tick hitting a task of our scheduling class.
*
* NOTE: This function can be called remotely by the tick offload that
* goes along full dynticks. Therefore no local assumption can be made
* and everything must be accessed through the @rq and @curr passed in
* parameters.
*/
static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued)
{
}
static void set_curr_task_idle(struct rq *rq)
{
}
static void switched_to_idle(struct rq *rq, struct task_struct *p)
{
BUG();
}
static void
prio_changed_idle(struct rq *rq, struct task_struct *p, int oldprio)
{
BUG();
}
static unsigned int get_rr_interval_idle(struct rq *rq, struct task_struct *task)
{
return 0;
}
static void update_curr_idle(struct rq *rq)
{
}
/*
* Simple, special scheduling class for the per-CPU idle tasks:
*/
const struct sched_class idle_sched_class = {
/* .next is NULL */
/* no enqueue/yield_task for idle tasks */
/* dequeue is not valid, we print a debug message there: */
.dequeue_task = dequeue_task_idle,
.check_preempt_curr = check_preempt_curr_idle,
.pick_next_task = pick_next_task_idle,
.put_prev_task = put_prev_task_idle,
#ifdef CONFIG_SMP
.select_task_rq = select_task_rq_idle,
.set_cpus_allowed = set_cpus_allowed_common,
#endif
.set_curr_task = set_curr_task_idle,
.task_tick = task_tick_idle,
.get_rr_interval = get_rr_interval_idle,
.prio_changed = prio_changed_idle,
.switched_to = switched_to_idle,
.update_curr = update_curr_idle,
};

110
kernel/sched/idle_task.c
View File

@@ -1,110 +0,0 @@
// SPDX-License-Identifier: GPL-2.0
#include "sched.h"
/*
* idle-task scheduling class.
*
* (NOTE: these are not related to SCHED_IDLE tasks which are
* handled in sched/fair.c)
*/
#ifdef CONFIG_SMP
static int
select_task_rq_idle(struct task_struct *p, int cpu, int sd_flag, int flags)
{
return task_cpu(p); /* IDLE tasks as never migrated */
}
#endif /* CONFIG_SMP */
/*
* Idle tasks are unconditionally rescheduled:
*/
static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int flags)
{
resched_curr(rq);
}
static struct task_struct *
pick_next_task_idle(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
{
put_prev_task(rq, prev);
update_idle_core(rq);
schedstat_inc(rq->sched_goidle);
return rq->idle;
}
/*
* It is not legal to sleep in the idle task - print a warning
* message if some code attempts to do it:
*/
static void
dequeue_task_idle(struct rq *rq, struct task_struct *p, int flags)
{
raw_spin_unlock_irq(&rq->lock);
printk(KERN_ERR "bad: scheduling from the idle thread!\n");
dump_stack();
raw_spin_lock_irq(&rq->lock);
}
static void put_prev_task_idle(struct rq *rq, struct task_struct *prev)
{
rq_last_tick_reset(rq);
}
static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued)
{
}
static void set_curr_task_idle(struct rq *rq)
{
}
static void switched_to_idle(struct rq *rq, struct task_struct *p)
{
BUG();
}
static void
prio_changed_idle(struct rq *rq, struct task_struct *p, int oldprio)
{
BUG();
}
static unsigned int get_rr_interval_idle(struct rq *rq, struct task_struct *task)
{
return 0;
}
static void update_curr_idle(struct rq *rq)
{
}
/*
* Simple, special scheduling class for the per-CPU idle tasks:
*/
const struct sched_class idle_sched_class = {
/* .next is NULL */
/* no enqueue/yield_task for idle tasks */
/* dequeue is not valid, we print a debug message there: */
.dequeue_task = dequeue_task_idle,
.check_preempt_curr = check_preempt_curr_idle,
.pick_next_task = pick_next_task_idle,
.put_prev_task = put_prev_task_idle,
#ifdef CONFIG_SMP
.select_task_rq = select_task_rq_idle,
.set_cpus_allowed = set_cpus_allowed_common,
#endif
.set_curr_task = set_curr_task_idle,
.task_tick = task_tick_idle,
.get_rr_interval = get_rr_interval_idle,
.prio_changed = prio_changed_idle,
.switched_to = switched_to_idle,
.update_curr = update_curr_idle,
};

14
kernel/sched/isolation.c
View File

@@ -3,15 +3,10 @@
* any CPU: unbound workqueues, timers, kthreads and any offloadable work.
*
* Copyright (C) 2017 Red Hat, Inc., Frederic Weisbecker
* Copyright (C) 2017-2018 SUSE, Frederic Weisbecker
*
*/
#include <linux/sched/isolation.h>
#include <linux/tick.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/static_key.h>
#include <linux/ctype.h>
#include "sched.h"
DEFINE_STATIC_KEY_FALSE(housekeeping_overriden);
EXPORT_SYMBOL_GPL(housekeeping_overriden);
@@ -60,6 +55,9 @@ void __init housekeeping_init(void)
static_branch_enable(&housekeeping_overriden);
if (housekeeping_flags & HK_FLAG_TICK)
sched_tick_offload_init();
/* We need at least one CPU to handle housekeeping work */
WARN_ON_ONCE(cpumask_empty(housekeeping_mask));
}
@@ -119,7 +117,7 @@ static int __init housekeeping_nohz_full_setup(char *str)
{
unsigned int flags;
flags = HK_FLAG_TICK | HK_FLAG_TIMER | HK_FLAG_RCU | HK_FLAG_MISC;
flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU | HK_FLAG_MISC;
return housekeeping_setup(str, flags);
}

34
kernel/sched/loadavg.c
View File

@@ -6,10 +6,6 @@
* figure. Its a silly number but people think its important. We go through
* great pains to make it work on big machines and tickless kernels.
*/
#include <linux/export.h>
#include <linux/sched/loadavg.h>
#include "sched.h"
/*
@@ -32,29 +28,29 @@
* Due to a number of reasons the above turns in the mess below:
*
* - for_each_possible_cpu() is prohibitively expensive on machines with
* serious number of cpus, therefore we need to take a distributed approach
* serious number of CPUs, therefore we need to take a distributed approach
* to calculating nr_active.
*
* \Sum_i x_i(t) = \Sum_i x_i(t) - x_i(t_0) | x_i(t_0) := 0
* = \Sum_i { \Sum_j=1 x_i(t_j) - x_i(t_j-1) }
*
* So assuming nr_active := 0 when we start out -- true per definition, we
* can simply take per-cpu deltas and fold those into a global accumulate
* can simply take per-CPU deltas and fold those into a global accumulate
* to obtain the same result. See calc_load_fold_active().
*
* Furthermore, in order to avoid synchronizing all per-cpu delta folding
* Furthermore, in order to avoid synchronizing all per-CPU delta folding
* across the machine, we assume 10 ticks is sufficient time for every
* cpu to have completed this task.
* CPU to have completed this task.
*
* This places an upper-bound on the IRQ-off latency of the machine. Then
* again, being late doesn't loose the delta, just wrecks the sample.
*
* - cpu_rq()->nr_uninterruptible isn't accurately tracked per-cpu because
* this would add another cross-cpu cacheline miss and atomic operation
* to the wakeup path. Instead we increment on whatever cpu the task ran
* when it went into uninterruptible state and decrement on whatever cpu
* - cpu_rq()->nr_uninterruptible isn't accurately tracked per-CPU because
* this would add another cross-CPU cacheline miss and atomic operation
* to the wakeup path. Instead we increment on whatever CPU the task ran
* when it went into uninterruptible state and decrement on whatever CPU
* did the wakeup. This means that only the sum of nr_uninterruptible over
* all cpus yields the correct result.
* all CPUs yields the correct result.
*
* This covers the NO_HZ=n code, for extra head-aches, see the comment below.
*/
@@ -115,11 +111,11 @@ calc_load(unsigned long load, unsigned long exp, unsigned long active)
* Handle NO_HZ for the global load-average.
*
* Since the above described distributed algorithm to compute the global
* load-average relies on per-cpu sampling from the tick, it is affected by
* load-average relies on per-CPU sampling from the tick, it is affected by
* NO_HZ.
*
* The basic idea is to fold the nr_active delta into a global NO_HZ-delta upon
* entering NO_HZ state such that we can include this as an 'extra' cpu delta
* entering NO_HZ state such that we can include this as an 'extra' CPU delta
* when we read the global state.
*
* Obviously reality has to ruin such a delightfully simple scheme:
@@ -146,9 +142,9 @@ calc_load(unsigned long load, unsigned long exp, unsigned long active)
* busy state.
*
* This is solved by pushing the window forward, and thus skipping the
* sample, for this cpu (effectively using the NO_HZ-delta for this cpu which
* sample, for this CPU (effectively using the NO_HZ-delta for this CPU which
* was in effect at the time the window opened). This also solves the issue
* of having to deal with a cpu having been in NO_HZ for multiple LOAD_FREQ
* of having to deal with a CPU having been in NO_HZ for multiple LOAD_FREQ
* intervals.
*
* When making the ILB scale, we should try to pull this in as well.
@@ -299,7 +295,7 @@ calc_load_n(unsigned long load, unsigned long exp,
}
/*
* NO_HZ can leave us missing all per-cpu ticks calling
* NO_HZ can leave us missing all per-CPU ticks calling
* calc_load_fold_active(), but since a NO_HZ CPU folds its delta into
* calc_load_nohz per calc_load_nohz_start(), all we need to do is fold
* in the pending NO_HZ delta if our NO_HZ period crossed a load cycle boundary.
@@ -363,7 +359,7 @@ void calc_global_load(unsigned long ticks)
return;
/*
* Fold the 'old' NO_HZ-delta to include all NO_HZ cpus.
* Fold the 'old' NO_HZ-delta to include all NO_HZ CPUs.
*/
delta = calc_load_nohz_fold();
if (delta)

27
kernel/sched/membarrier.c
View File

@@ -13,32 +13,25 @@
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/syscalls.h>
#include <linux/membarrier.h>
#include <linux/tick.h>
#include <linux/cpumask.h>
#include <linux/atomic.h>
#include "sched.h" /* for cpu_rq(). */
#include "sched.h"
/*
* Bitmask made from a "or" of all commands within enum membarrier_cmd,
* except MEMBARRIER_CMD_QUERY.
*/
#ifdef CONFIG_ARCH_HAS_MEMBARRIER_SYNC_CORE
#define MEMBARRIER_PRIVATE_EXPEDITED_SYNC_CORE_BITMASK \
(MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE \
#define MEMBARRIER_PRIVATE_EXPEDITED_SYNC_CORE_BITMASK \
(MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE \
| MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_SYNC_CORE)
#else
#define MEMBARRIER_PRIVATE_EXPEDITED_SYNC_CORE_BITMASK 0
#endif
#define MEMBARRIER_CMD_BITMASK \
(MEMBARRIER_CMD_GLOBAL | MEMBARRIER_CMD_GLOBAL_EXPEDITED \
| MEMBARRIER_CMD_REGISTER_GLOBAL_EXPEDITED \
| MEMBARRIER_CMD_PRIVATE_EXPEDITED \
| MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED \
#define MEMBARRIER_CMD_BITMASK \
(MEMBARRIER_CMD_GLOBAL | MEMBARRIER_CMD_GLOBAL_EXPEDITED \
| MEMBARRIER_CMD_REGISTER_GLOBAL_EXPEDITED \
| MEMBARRIER_CMD_PRIVATE_EXPEDITED \
| MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED \
| MEMBARRIER_PRIVATE_EXPEDITED_SYNC_CORE_BITMASK)
static void ipi_mb(void *info)
@@ -85,6 +78,7 @@ static int membarrier_global_expedited(void)
*/
if (cpu == raw_smp_processor_id())
continue;
rcu_read_lock();
p = task_rcu_dereference(&cpu_rq(cpu)->curr);
if (p && p->mm && (atomic_read(&p->mm->membarrier_state) &
@@ -188,6 +182,7 @@ static int membarrier_private_expedited(int flags)
* rq->curr modification in scheduler.
*/
smp_mb(); /* exit from system call is not a mb */
return 0;
}
@@ -219,6 +214,7 @@ static int membarrier_register_global_expedited(void)
}
atomic_or(MEMBARRIER_STATE_GLOBAL_EXPEDITED_READY,
&mm->membarrier_state);
return 0;
}
@@ -253,6 +249,7 @@ static int membarrier_register_private_expedited(int flags)
synchronize_sched();
}
atomic_or(state, &mm->membarrier_state);
return 0;
}

51
kernel/sched/rt.c
View File

@@ -3,12 +3,8 @@
* Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR
* policies)
*/
#include "sched.h"
#include <linux/slab.h>
#include <linux/irq_work.h>
int sched_rr_timeslice = RR_TIMESLICE;
int sysctl_sched_rr_timeslice = (MSEC_PER_SEC / HZ) * RR_TIMESLICE;
@@ -359,7 +355,7 @@ static DEFINE_PER_CPU(struct callback_head, rt_pull_head);
static void push_rt_tasks(struct rq *);
static void pull_rt_task(struct rq *);
static inline void queue_push_tasks(struct rq *rq)
static inline void rt_queue_push_tasks(struct rq *rq)
{
if (!has_pushable_tasks(rq))
return;
@@ -367,7 +363,7 @@ static inline void queue_push_tasks(struct rq *rq)
queue_balance_callback(rq, &per_cpu(rt_push_head, rq->cpu), push_rt_tasks);
}
static inline void queue_pull_task(struct rq *rq)
static inline void rt_queue_pull_task(struct rq *rq)
{
queue_balance_callback(rq, &per_cpu(rt_pull_head, rq->cpu), pull_rt_task);
}
@@ -425,7 +421,7 @@ static inline void pull_rt_task(struct rq *this_rq)
{
}
static inline void queue_push_tasks(struct rq *rq)
static inline void rt_queue_push_tasks(struct rq *rq)
{
}
#endif /* CONFIG_SMP */
@@ -1453,9 +1449,9 @@ static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
return;
/*
* There appears to be other cpus that can accept
* current and none to run 'p', so lets reschedule
* to try and push current away:
* There appear to be other CPUs that can accept
* the current task but none can run 'p', so lets reschedule
* to try and push the current task away:
*/
requeue_task_rt(rq, p, 1);
resched_curr(rq);
@@ -1569,7 +1565,7 @@ pick_next_task_rt(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
/* The running task is never eligible for pushing */
dequeue_pushable_task(rq, p);
queue_push_tasks(rq);
rt_queue_push_tasks(rq);
return p;
}
@@ -1596,12 +1592,13 @@ static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)
if (!task_running(rq, p) &&
cpumask_test_cpu(cpu, &p->cpus_allowed))
return 1;
return 0;
}
/*
* Return the highest pushable rq's task, which is suitable to be executed
* on the cpu, NULL otherwise
* on the CPU, NULL otherwise
*/
static struct task_struct *pick_highest_pushable_task(struct rq *rq, int cpu)
{
@@ -1639,11 +1636,11 @@ static int find_lowest_rq(struct task_struct *task)
return -1; /* No targets found */
/*
* At this point we have built a mask of cpus representing the
* At this point we have built a mask of CPUs representing the
* lowest priority tasks in the system. Now we want to elect
* the best one based on our affinity and topology.
*
* We prioritize the last cpu that the task executed on since
* We prioritize the last CPU that the task executed on since
* it is most likely cache-hot in that location.
*/
if (cpumask_test_cpu(cpu, lowest_mask))
@@ -1651,7 +1648,7 @@ static int find_lowest_rq(struct task_struct *task)
/*
* Otherwise, we consult the sched_domains span maps to figure
* out which cpu is logically closest to our hot cache data.
* out which CPU is logically closest to our hot cache data.
*/
if (!cpumask_test_cpu(this_cpu, lowest_mask))
this_cpu = -1; /* Skip this_cpu opt if not among lowest */
@@ -1692,6 +1689,7 @@ static int find_lowest_rq(struct task_struct *task)
cpu = cpumask_any(lowest_mask);
if (cpu < nr_cpu_ids)
return cpu;
return -1;
}
@@ -1827,7 +1825,7 @@ retry:
* The task hasn't migrated, and is still the next
* eligible task, but we failed to find a run-queue
* to push it to. Do not retry in this case, since
* other cpus will pull from us when ready.
* other CPUs will pull from us when ready.
*/
goto out;
}
@@ -1919,7 +1917,7 @@ static int rto_next_cpu(struct root_domain *rd)
* rt_next_cpu() will simply return the first CPU found in
* the rto_mask.
*
* If rto_next_cpu() is called with rto_cpu is a valid cpu, it
* If rto_next_cpu() is called with rto_cpu is a valid CPU, it
* will return the next CPU found in the rto_mask.
*
* If there are no more CPUs left in the rto_mask, then a check is made
@@ -1980,7 +1978,7 @@ static void tell_cpu_to_push(struct rq *rq)
raw_spin_lock(&rq->rd->rto_lock);
/*
* The rto_cpu is updated under the lock, if it has a valid cpu
* The rto_cpu is updated under the lock, if it has a valid CPU
* then the IPI is still running and will continue due to the
* update to loop_next, and nothing needs to be done here.
* Otherwise it is finishing up and an ipi needs to be sent.
@@ -2105,7 +2103,7 @@ static void pull_rt_task(struct rq *this_rq)
/*
* There's a chance that p is higher in priority
* than what's currently running on its cpu.
* than what's currently running on its CPU.
* This is just that p is wakeing up and hasn't
* had a chance to schedule. We only pull
* p if it is lower in priority than the
@@ -2187,7 +2185,7 @@ static void switched_from_rt(struct rq *rq, struct task_struct *p)
if (!task_on_rq_queued(p) || rq->rt.rt_nr_running)
return;
queue_pull_task(rq);
rt_queue_pull_task(rq);
}
void __init init_sched_rt_class(void)
@@ -2218,7 +2216,7 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p)
if (task_on_rq_queued(p) && rq->curr != p) {
#ifdef CONFIG_SMP
if (p->nr_cpus_allowed > 1 && rq->rt.overloaded)
queue_push_tasks(rq);
rt_queue_push_tasks(rq);
#endif /* CONFIG_SMP */
if (p->prio < rq->curr->prio && cpu_online(cpu_of(rq)))
resched_curr(rq);
@@ -2242,7 +2240,7 @@ prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)
* may need to pull tasks to this runqueue.
*/
if (oldprio < p->prio)
queue_pull_task(rq);
rt_queue_pull_task(rq);
/*
* If there's a higher priority task waiting to run
@@ -2292,6 +2290,14 @@ static void watchdog(struct rq *rq, struct task_struct *p)
static inline void watchdog(struct rq *rq, struct task_struct *p) { }
#endif
/*
* scheduler tick hitting a task of our scheduling class.
*
* NOTE: This function can be called remotely by the tick offload that
* goes along full dynticks. Therefore no local assumption can be made
* and everything must be accessed through the @rq and @curr passed in
* parameters.
*/
static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
{
struct sched_rt_entity *rt_se = &p->rt;
@@ -2685,6 +2691,7 @@ int sched_rr_handler(struct ctl_table *table, int write,
msecs_to_jiffies(sysctl_sched_rr_timeslice);
}
mutex_unlock(&mutex);
return ret;
}

617
kernel/sched/sched.h
View File

File diff suppressed because it is too large Load Diff

20
kernel/sched/stats.c
View File

@@ -1,14 +1,13 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
/*
* /proc/schedstat implementation
*/
#include "sched.h"
/*
* bump this up when changing the output format or the meaning of an existing
* Current schedstat API version.
*
* Bump this up when changing the output format or the meaning of an existing
* format, so that tools can adapt (or abort)
*/
#define SCHEDSTAT_VERSION 15
@@ -78,8 +77,8 @@ static int show_schedstat(struct seq_file *seq, void *v)
* This itererator needs some explanation.
* It returns 1 for the header position.
* This means 2 is cpu 0.
* In a hotplugged system some cpus, including cpu 0, may be missing so we have
* to use cpumask_* to iterate over the cpus.
* In a hotplugged system some CPUs, including cpu 0, may be missing so we have
* to use cpumask_* to iterate over the CPUs.
*/
static void *schedstat_start(struct seq_file *file, loff_t *offset)
{
@@ -99,12 +98,14 @@ static void *schedstat_start(struct seq_file *file, loff_t *offset)
if (n < nr_cpu_ids)
return (void *)(unsigned long)(n + 2);
return NULL;
}
static void *schedstat_next(struct seq_file *file, void *data, loff_t *offset)
{
(*offset)++;
return schedstat_start(file, offset);
}
@@ -134,6 +135,7 @@ static const struct file_operations proc_schedstat_operations = {
static int __init proc_schedstat_init(void)
{
proc_create("schedstat", 0, NULL, &proc_schedstat_operations);
return 0;
}
subsys_initcall(proc_schedstat_init);

84
kernel/sched/stats.h
View File

@@ -30,35 +30,29 @@ rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
if (rq)
rq->rq_sched_info.run_delay += delta;
}
#define schedstat_enabled() static_branch_unlikely(&sched_schedstats)
#define schedstat_enabled() static_branch_unlikely(&sched_schedstats)
#define __schedstat_inc(var) do { var++; } while (0)
#define schedstat_inc(var) do { if (schedstat_enabled()) { var++; } } while (0)
#define schedstat_inc(var) do { if (schedstat_enabled()) { var++; } } while (0)
#define __schedstat_add(var, amt) do { var += (amt); } while (0)
#define schedstat_add(var, amt) do { if (schedstat_enabled()) { var += (amt); } } while (0)
#define __schedstat_set(var, val) do { var = (val); } while (0)
#define schedstat_set(var, val) do { if (schedstat_enabled()) { var = (val); } } while (0)
#define schedstat_val(var) (var)
#define schedstat_val_or_zero(var) ((schedstat_enabled()) ? (var) : 0)
#define schedstat_add(var, amt) do { if (schedstat_enabled()) { var += (amt); } } while (0)
#define __schedstat_set(var, val) do { var = (val); } while (0)
#define schedstat_set(var, val) do { if (schedstat_enabled()) { var = (val); } } while (0)
#define schedstat_val(var) (var)
#define schedstat_val_or_zero(var) ((schedstat_enabled()) ? (var) : 0)
#else /* !CONFIG_SCHEDSTATS */
static inline void
rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
{}
static inline void
rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
{}
static inline void
rq_sched_info_depart(struct rq *rq, unsigned long long delta)
{}
#define schedstat_enabled() 0
#define __schedstat_inc(var) do { } while (0)
#define schedstat_inc(var) do { } while (0)
#define __schedstat_add(var, amt) do { } while (0)
#define schedstat_add(var, amt) do { } while (0)
#define __schedstat_set(var, val) do { } while (0)
#define schedstat_set(var, val) do { } while (0)
#define schedstat_val(var) 0
#define schedstat_val_or_zero(var) 0
#else /* !CONFIG_SCHEDSTATS: */
static inline void rq_sched_info_arrive (struct rq *rq, unsigned long long delta) { }
static inline void rq_sched_info_dequeued(struct rq *rq, unsigned long long delta) { }
static inline void rq_sched_info_depart (struct rq *rq, unsigned long long delta) { }
# define schedstat_enabled() 0
# define __schedstat_inc(var) do { } while (0)
# define schedstat_inc(var) do { } while (0)
# define __schedstat_add(var, amt) do { } while (0)
# define schedstat_add(var, amt) do { } while (0)
# define __schedstat_set(var, val) do { } while (0)
# define schedstat_set(var, val) do { } while (0)
# define schedstat_val(var) 0
# define schedstat_val_or_zero(var) 0
#endif /* CONFIG_SCHEDSTATS */
#ifdef CONFIG_SCHED_INFO
@@ -69,9 +63,9 @@ static inline void sched_info_reset_dequeued(struct task_struct *t)
/*
* We are interested in knowing how long it was from the *first* time a
* task was queued to the time that it finally hit a cpu, we call this routine
* from dequeue_task() to account for possible rq->clock skew across cpus. The
* delta taken on each cpu would annul the skew.
* task was queued to the time that it finally hit a CPU, we call this routine
* from dequeue_task() to account for possible rq->clock skew across CPUs. The
* delta taken on each CPU would annul the skew.
*/
static inline void sched_info_dequeued(struct rq *rq, struct task_struct *t)
{
@@ -87,7 +81,7 @@ static inline void sched_info_dequeued(struct rq *rq, struct task_struct *t)
}
/*
* Called when a task finally hits the cpu. We can now calculate how
* Called when a task finally hits the CPU. We can now calculate how
* long it was waiting to run. We also note when it began so that we
* can keep stats on how long its timeslice is.
*/
@@ -112,9 +106,10 @@ static void sched_info_arrive(struct rq *rq, struct task_struct *t)
*/
static inline void sched_info_queued(struct rq *rq, struct task_struct *t)
{
if (unlikely(sched_info_on()))
if (unlikely(sched_info_on())) {
if (!t->sched_info.last_queued)
t->sched_info.last_queued = rq_clock(rq);
}
}
/*
@@ -127,8 +122,7 @@ static inline void sched_info_queued(struct rq *rq, struct task_struct *t)
*/
static inline void sched_info_depart(struct rq *rq, struct task_struct *t)
{
unsigned long long delta = rq_clock(rq) -
t->sched_info.last_arrival;
unsigned long long delta = rq_clock(rq) - t->sched_info.last_arrival;
rq_sched_info_depart(rq, delta);
@@ -142,11 +136,10 @@ static inline void sched_info_depart(struct rq *rq, struct task_struct *t)
* the idle task.) We are only called when prev != next.
*/
static inline void
__sched_info_switch(struct rq *rq,
struct task_struct *prev, struct task_struct *next)
__sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next)
{
/*
* prev now departs the cpu. It's not interesting to record
* prev now departs the CPU. It's not interesting to record
* stats about how efficient we were at scheduling the idle
* process, however.
*/
@@ -156,18 +149,19 @@ __sched_info_switch(struct rq *rq,
if (next != rq->idle)
sched_info_arrive(rq, next);
}
static inline void
sched_info_switch(struct rq *rq,
struct task_struct *prev, struct task_struct *next)
sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next)
{
if (unlikely(sched_info_on()))
__sched_info_switch(rq, prev, next);
}
#else
#define sched_info_queued(rq, t) do { } while (0)
#define sched_info_reset_dequeued(t) do { } while (0)
#define sched_info_dequeued(rq, t) do { } while (0)
#define sched_info_depart(rq, t) do { } while (0)
#define sched_info_arrive(rq, next) do { } while (0)
#define sched_info_switch(rq, t, next) do { } while (0)
#else /* !CONFIG_SCHED_INFO: */
# define sched_info_queued(rq, t) do { } while (0)
# define sched_info_reset_dequeued(t) do { } while (0)
# define sched_info_dequeued(rq, t) do { } while (0)
# define sched_info_depart(rq, t) do { } while (0)
# define sched_info_arrive(rq, next) do { } while (0)
# define sched_info_switch(rq, t, next) do { } while (0)
#endif /* CONFIG_SCHED_INFO */

11
kernel/sched/stop_task.c
View File

@@ -1,6 +1,4 @@
// SPDX-License-Identifier: GPL-2.0
#include "sched.h"
/*
* stop-task scheduling class.
*
@@ -9,6 +7,7 @@
*
* See kernel/stop_machine.c
*/
#include "sched.h"
#ifdef CONFIG_SMP
static int
@@ -75,6 +74,14 @@ static void put_prev_task_stop(struct rq *rq, struct task_struct *prev)
cgroup_account_cputime(curr, delta_exec);
}
/*
* scheduler tick hitting a task of our scheduling class.
*
* NOTE: This function can be called remotely by the tick offload that
* goes along full dynticks. Therefore no local assumption can be made
* and everything must be accessed through the @rq and @curr passed in
* parameters.
*/
static void task_tick_stop(struct rq *rq, struct task_struct *curr, int queued)
{
}

6
kernel/sched/swait.c
View File

@@ -1,6 +1,8 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/sched/signal.h>
#include <linux/swait.h>
/*
* <linux/swait.h> (simple wait queues ) implementation:
*/
#include "sched.h"
void __init_swait_queue_head(struct swait_queue_head *q, const char *name,
struct lock_class_key *key)

46
kernel/sched/topology.c
View File

@@ -2,10 +2,6 @@
/*
* Scheduler topology setup/handling methods
*/
#include <linux/sched.h>
#include <linux/mutex.h>
#include <linux/sched/isolation.h>
#include "sched.h"
DEFINE_MUTEX(sched_domains_mutex);
@@ -41,8 +37,7 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
if (!(sd->flags & SD_LOAD_BALANCE)) {
printk("does not load-balance\n");
if (sd->parent)
printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain"
" has parent");
printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain has parent");
return -1;
}
@@ -50,12 +45,10 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
cpumask_pr_args(sched_domain_span(sd)), sd->name);
if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) {
printk(KERN_ERR "ERROR: domain->span does not contain "
"CPU%d\n", cpu);
printk(KERN_ERR "ERROR: domain->span does not contain CPU%d\n", cpu);
}
if (!cpumask_test_cpu(cpu, sched_group_span(group))) {
printk(KERN_ERR "ERROR: domain->groups does not contain"
" CPU%d\n", cpu);
printk(KERN_ERR "ERROR: domain->groups does not contain CPU%d\n", cpu);
}
printk(KERN_DEBUG "%*s groups:", level + 1, "");
@@ -115,8 +108,7 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
if (sd->parent &&
!cpumask_subset(groupmask, sched_domain_span(sd->parent)))
printk(KERN_ERR "ERROR: parent span is not a superset "
"of domain->span\n");
printk(KERN_ERR "ERROR: parent span is not a superset of domain->span\n");
return 0;
}
@@ -595,7 +587,7 @@ int group_balance_cpu(struct sched_group *sg)
* are not.
*
* This leads to a few particularly weird cases where the sched_domain's are
* not of the same number for each cpu. Consider:
* not of the same number for each CPU. Consider:
*
* NUMA-2 0-3 0-3
* groups: {0-2},{1-3} {1-3},{0-2}
@@ -780,7 +772,7 @@ fail:
* ^ ^ ^ ^
* `-' `-'
*
* The sched_domains are per-cpu and have a two way link (parent & child) and
* The sched_domains are per-CPU and have a two way link (parent & child) and
* denote the ever growing mask of CPUs belonging to that level of topology.
*
* Each sched_domain has a circular (double) linked list of sched_group's, each
@@ -1021,6 +1013,7 @@ __visit_domain_allocation_hell(struct s_data *d, const struct cpumask *cpu_map)
d->rd = alloc_rootdomain();
if (!d->rd)
return sa_sd;
return sa_rootdomain;
}
@@ -1047,12 +1040,14 @@ static void claim_allocations(int cpu, struct sched_domain *sd)
}
#ifdef CONFIG_NUMA
static int sched_domains_numa_levels;
enum numa_topology_type sched_numa_topology_type;
static int *sched_domains_numa_distance;
int sched_max_numa_distance;
static struct cpumask ***sched_domains_numa_masks;
static int sched_domains_curr_level;
static int sched_domains_numa_levels;
static int sched_domains_curr_level;
int sched_max_numa_distance;
static int *sched_domains_numa_distance;
static struct cpumask ***sched_domains_numa_masks;
#endif
/*
@@ -1074,11 +1069,11 @@ static int sched_domains_curr_level;
* SD_ASYM_PACKING - describes SMT quirks
*/
#define TOPOLOGY_SD_FLAGS \
(SD_SHARE_CPUCAPACITY | \
(SD_SHARE_CPUCAPACITY | \
SD_SHARE_PKG_RESOURCES | \
SD_NUMA | \
SD_ASYM_PACKING | \
SD_ASYM_CPUCAPACITY | \
SD_NUMA | \
SD_ASYM_PACKING | \
SD_ASYM_CPUCAPACITY | \
SD_SHARE_POWERDOMAIN)
static struct sched_domain *
@@ -1628,7 +1623,7 @@ static struct sched_domain *build_sched_domain(struct sched_domain_topology_leve
pr_err(" the %s domain not a subset of the %s domain\n",
child->name, sd->name);
#endif
/* Fixup, ensure @sd has at least @child cpus. */
/* Fixup, ensure @sd has at least @child CPUs. */
cpumask_or(sched_domain_span(sd),
sched_domain_span(sd),
sched_domain_span(child));
@@ -1720,6 +1715,7 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att
ret = 0;
error:
__free_domain_allocs(&d, alloc_state, cpu_map);
return ret;
}
@@ -1824,6 +1820,7 @@ static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
return 1;
tmp = SD_ATTR_INIT;
return !memcmp(cur ? (cur + idx_cur) : &tmp,
new ? (new + idx_new) : &tmp,
sizeof(struct sched_domain_attr));
@@ -1929,4 +1926,3 @@ match2:
mutex_unlock(&sched_domains_mutex);
}

13
kernel/sched/wait.c
View File

@@ -3,14 +3,7 @@
*
* (C) 2004 Nadia Yvette Chambers, Oracle
*/
#include <linux/init.h>
#include <linux/export.h>
#include <linux/sched/signal.h>
#include <linux/sched/debug.h>
#include <linux/mm.h>
#include <linux/wait.h>
#include <linux/hash.h>
#include <linux/kthread.h>
#include "sched.h"
void __init_waitqueue_head(struct wait_queue_head *wq_head, const char *name, struct lock_class_key *key)
{
@@ -107,6 +100,7 @@ static int __wake_up_common(struct wait_queue_head *wq_head, unsigned int mode,
break;
}
}
return nr_exclusive;
}
@@ -317,6 +311,7 @@ int do_wait_intr(wait_queue_head_t *wq, wait_queue_entry_t *wait)
spin_unlock(&wq->lock);
schedule();
spin_lock(&wq->lock);
return 0;
}
EXPORT_SYMBOL(do_wait_intr);
@@ -333,6 +328,7 @@ int do_wait_intr_irq(wait_queue_head_t *wq, wait_queue_entry_t *wait)
spin_unlock_irq(&wq->lock);
schedule();
spin_lock_irq(&wq->lock);
return 0;
}
EXPORT_SYMBOL(do_wait_intr_irq);
@@ -378,6 +374,7 @@ int autoremove_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, i
if (ret)
list_del_init(&wq_entry->entry);
return ret;
}
EXPORT_SYMBOL(autoremove_wake_function);

71
kernel/sched/wait_bit.c
View File

@@ -1,10 +1,7 @@
/*
* The implementation of the wait_bit*() and related waiting APIs:
*/
#include <linux/wait_bit.h>
#include <linux/sched/signal.h>
#include <linux/sched/debug.h>
#include <linux/hash.h>
#include "sched.h"
#define WAIT_TABLE_BITS 8
#define WAIT_TABLE_SIZE (1 << WAIT_TABLE_BITS)
@@ -29,8 +26,8 @@ int wake_bit_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync
wait_bit->key.bit_nr != key->bit_nr ||
test_bit(key->bit_nr, key->flags))
return 0;
else
return autoremove_wake_function(wq_entry, mode, sync, key);
return autoremove_wake_function(wq_entry, mode, sync, key);
}
EXPORT_SYMBOL(wake_bit_function);
@@ -50,7 +47,9 @@ __wait_on_bit(struct wait_queue_head *wq_head, struct wait_bit_queue_entry *wbq_
if (test_bit(wbq_entry->key.bit_nr, wbq_entry->key.flags))
ret = (*action)(&wbq_entry->key, mode);
} while (test_bit(wbq_entry->key.bit_nr, wbq_entry->key.flags) && !ret);
finish_wait(wq_head, &wbq_entry->wq_entry);
return ret;
}
EXPORT_SYMBOL(__wait_on_bit);
@@ -73,6 +72,7 @@ int __sched out_of_line_wait_on_bit_timeout(
DEFINE_WAIT_BIT(wq_entry, word, bit);
wq_entry.key.timeout = jiffies + timeout;
return __wait_on_bit(wq_head, &wq_entry, action, mode);
}
EXPORT_SYMBOL_GPL(out_of_line_wait_on_bit_timeout);
@@ -120,6 +120,7 @@ EXPORT_SYMBOL(out_of_line_wait_on_bit_lock);
void __wake_up_bit(struct wait_queue_head *wq_head, void *word, int bit)
{
struct wait_bit_key key = __WAIT_BIT_KEY_INITIALIZER(word, bit);
if (waitqueue_active(wq_head))
__wake_up(wq_head, TASK_NORMAL, 1, &key);
}
@@ -148,6 +149,54 @@ void wake_up_bit(void *word, int bit)
}
EXPORT_SYMBOL(wake_up_bit);
wait_queue_head_t *__var_waitqueue(void *p)
{
if (BITS_PER_LONG == 64) {
unsigned long q = (unsigned long)p;
return bit_waitqueue((void *)(q & ~1), q & 1);
}
return bit_waitqueue(p, 0);
}
EXPORT_SYMBOL(__var_waitqueue);
static int
var_wake_function(struct wait_queue_entry *wq_entry, unsigned int mode,
int sync, void *arg)
{
struct wait_bit_key *key = arg;
struct wait_bit_queue_entry *wbq_entry =
container_of(wq_entry, struct wait_bit_queue_entry, wq_entry);
if (wbq_entry->key.flags != key->flags ||
wbq_entry->key.bit_nr != key->bit_nr)
return 0;
return autoremove_wake_function(wq_entry, mode, sync, key);
}
void init_wait_var_entry(struct wait_bit_queue_entry *wbq_entry, void *var, int flags)
{
*wbq_entry = (struct wait_bit_queue_entry){
.key = {
.flags = (var),
.bit_nr = -1,
},
.wq_entry = {
.private = current,
.func = var_wake_function,
.entry = LIST_HEAD_INIT(wbq_entry->wq_entry.entry),
},
};
}
EXPORT_SYMBOL(init_wait_var_entry);
void wake_up_var(void *var)
{
__wake_up_bit(__var_waitqueue(var), var, -1);
}
EXPORT_SYMBOL(wake_up_var);
/*
* Manipulate the atomic_t address to produce a better bit waitqueue table hash
* index (we're keying off bit -1, but that would produce a horrible hash
@@ -157,6 +206,7 @@ static inline wait_queue_head_t *atomic_t_waitqueue(atomic_t *p)
{
if (BITS_PER_LONG == 64) {
unsigned long q = (unsigned long)p;
return bit_waitqueue((void *)(q & ~1), q & 1);
}
return bit_waitqueue(p, 0);
@@ -173,6 +223,7 @@ static int wake_atomic_t_function(struct wait_queue_entry *wq_entry, unsigned mo
wait_bit->key.bit_nr != key->bit_nr ||
atomic_read(val) != 0)
return 0;
return autoremove_wake_function(wq_entry, mode, sync, key);
}
@@ -196,6 +247,7 @@ int __wait_on_atomic_t(struct wait_queue_head *wq_head, struct wait_bit_queue_en
ret = (*action)(val, mode);
} while (!ret && atomic_read(val) != 0);
finish_wait(wq_head, &wbq_entry->wq_entry);
return ret;
}
@@ -226,6 +278,7 @@ __sched int atomic_t_wait(atomic_t *counter, unsigned int mode)
schedule();
if (signal_pending_state(mode, current))
return -EINTR;
return 0;
}
EXPORT_SYMBOL(atomic_t_wait);
@@ -250,6 +303,7 @@ __sched int bit_wait(struct wait_bit_key *word, int mode)
schedule();
if (signal_pending_state(mode, current))
return -EINTR;
return 0;
}
EXPORT_SYMBOL(bit_wait);
@@ -259,6 +313,7 @@ __sched int bit_wait_io(struct wait_bit_key *word, int mode)
io_schedule();
if (signal_pending_state(mode, current))
return -EINTR;
return 0;
}
EXPORT_SYMBOL(bit_wait_io);
@@ -266,11 +321,13 @@ EXPORT_SYMBOL(bit_wait_io);
__sched int bit_wait_timeout(struct wait_bit_key *word, int mode)
{
unsigned long now = READ_ONCE(jiffies);
if (time_after_eq(now, word->timeout))
return -EAGAIN;
schedule_timeout(word->timeout - now);
if (signal_pending_state(mode, current))
return -EINTR;
return 0;
}
EXPORT_SYMBOL_GPL(bit_wait_timeout);
@@ -278,11 +335,13 @@ EXPORT_SYMBOL_GPL(bit_wait_timeout);
__sched int bit_wait_io_timeout(struct wait_bit_key *word, int mode)
{
unsigned long now = READ_ONCE(jiffies);
if (time_after_eq(now, word->timeout))
return -EAGAIN;
io_schedule_timeout(word->timeout - now);
if (signal_pending_state(mode, current))
return -EINTR;
return 0;
}
EXPORT_SYMBOL_GPL(bit_wait_io_timeout);

15
kernel/time/tick-sched.c
View File

@@ -481,11 +481,18 @@ static int __init setup_tick_nohz(char *str)
__setup("nohz=", setup_tick_nohz);
int tick_nohz_tick_stopped(void)
bool tick_nohz_tick_stopped(void)
{
return __this_cpu_read(tick_cpu_sched.tick_stopped);
}
bool tick_nohz_tick_stopped_cpu(int cpu)
{
struct tick_sched *ts = per_cpu_ptr(&tick_cpu_sched, cpu);
return ts->tick_stopped;
}
/**
* tick_nohz_update_jiffies - update jiffies when idle was interrupted
*
@@ -741,12 +748,6 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
delta = KTIME_MAX;
}
#ifdef CONFIG_NO_HZ_FULL
/* Limit the tick delta to the maximum scheduler deferment */
if (!ts->inidle)
delta = min(delta, scheduler_tick_max_deferment());
#endif
/* Calculate the next expiry time */
if (delta < (KTIME_MAX - basemono))
expires = basemono + delta;

3
kernel/workqueue.c
View File

@@ -5573,12 +5573,13 @@ static void __init wq_numa_init(void)
int __init workqueue_init_early(void)
{
int std_nice[NR_STD_WORKER_POOLS] = { 0, HIGHPRI_NICE_LEVEL };
int hk_flags = HK_FLAG_DOMAIN | HK_FLAG_WQ;
int i, cpu;
WARN_ON(__alignof__(struct pool_workqueue) < __alignof__(long long));
BUG_ON(!alloc_cpumask_var(&wq_unbound_cpumask, GFP_KERNEL));
cpumask_copy(wq_unbound_cpumask, housekeeping_cpumask(HK_FLAG_DOMAIN));
cpumask_copy(wq_unbound_cpumask, housekeeping_cpumask(hk_flags));
pwq_cache = KMEM_CACHE(pool_workqueue, SLAB_PANIC);