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Merge branch 'sched/for-linus' into tracing/for-linus

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This commit is contained in:
Ingo Molnar
2008-07-14 16:11:02 +02:00
parent d59fdcf2ac 873a6ed628
commit d14c8a680c
18 changed files with 1555 additions and 570 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kernel/Makefile
+3 -2
View File
@@ -3,7 +3,7 @@
#
obj-y = sched.o fork.o exec_domain.o panic.o printk.o profile.o \
exit.o itimer.o time.o softirq.o resource.o \
cpu.o exit.o itimer.o time.o softirq.o resource.o \
sysctl.o capability.o ptrace.o timer.o user.o \
signal.o sys.o kmod.o workqueue.o pid.o \
rcupdate.o extable.o params.o posix-timers.o \
@@ -27,7 +27,7 @@ obj-$(CONFIG_RT_MUTEXES) += rtmutex.o
obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o
obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o
obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
obj-$(CONFIG_SMP) += cpu.o spinlock.o
obj-$(CONFIG_SMP) += spinlock.o
obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o
obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
obj-$(CONFIG_UID16) += uid16.o
@@ -69,6 +69,7 @@ obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
obj-$(CONFIG_MARKERS) += marker.o
obj-$(CONFIG_LATENCYTOP) += latencytop.o
obj-$(CONFIG_SMP) += sched_cpupri.o
ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y)
# According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
kernel/cpu.c
+24
View File
@@ -15,6 +15,28 @@
#include <linux/stop_machine.h>
#include <linux/mutex.h>
/*
* Represents all cpu's present in the system
* In systems capable of hotplug, this map could dynamically grow
* as new cpu's are detected in the system via any platform specific
* method, such as ACPI for e.g.
*/
cpumask_t cpu_present_map __read_mostly;
EXPORT_SYMBOL(cpu_present_map);
#ifndef CONFIG_SMP
/*
* Represents all cpu's that are currently online.
*/
cpumask_t cpu_online_map __read_mostly = CPU_MASK_ALL;
EXPORT_SYMBOL(cpu_online_map);
cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL;
EXPORT_SYMBOL(cpu_possible_map);
#else /* CONFIG_SMP */
/* Serializes the updates to cpu_online_map, cpu_present_map */
static DEFINE_MUTEX(cpu_add_remove_lock);
@@ -403,3 +425,5 @@ out:
cpu_maps_update_done();
}
#endif /* CONFIG_PM_SLEEP_SMP */
#endif /* CONFIG_SMP */
kernel/cpuset.c
+13 -1
View File
@@ -1194,6 +1194,15 @@ static int cpuset_can_attach(struct cgroup_subsys *ss,
if (cpus_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
return -ENOSPC;
if (tsk->flags & PF_THREAD_BOUND) {
cpumask_t mask;
mutex_lock(&callback_mutex);
mask = cs->cpus_allowed;
mutex_unlock(&callback_mutex);
if (!cpus_equal(tsk->cpus_allowed, mask))
return -EINVAL;
}
return security_task_setscheduler(tsk, 0, NULL);
}
@@ -1207,11 +1216,14 @@ static void cpuset_attach(struct cgroup_subsys *ss,
struct mm_struct *mm;
struct cpuset *cs = cgroup_cs(cont);
struct cpuset *oldcs = cgroup_cs(oldcont);
int err;
mutex_lock(&callback_mutex);
guarantee_online_cpus(cs, &cpus);
set_cpus_allowed_ptr(tsk, &cpus);
err = set_cpus_allowed_ptr(tsk, &cpus);
mutex_unlock(&callback_mutex);
if (err)
return;
from = oldcs->mems_allowed;
to = cs->mems_allowed;
kernel/kthread.c
+1
View File
@@ -180,6 +180,7 @@ void kthread_bind(struct task_struct *k, unsigned int cpu)
set_task_cpu(k, cpu);
k->cpus_allowed = cpumask_of_cpu(cpu);
k->rt.nr_cpus_allowed = 1;
k->flags |= PF_THREAD_BOUND;
}
EXPORT_SYMBOL(kthread_bind);
kernel/sched.c
+491 -232
View File
File diff suppressed because it is too large Load Diff
kernel/sched_clock.c
+118 -19
View File
@@ -3,6 +3,9 @@
*
* Copyright (C) 2008 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
*
* Updates and enhancements:
* Copyright (C) 2008 Red Hat, Inc. Steven Rostedt <srostedt@redhat.com>
*
* Based on code by:
* Ingo Molnar <mingo@redhat.com>
* Guillaume Chazarain <guichaz@gmail.com>
@@ -32,6 +35,11 @@
#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
#define MULTI_SHIFT 15
/* Max is double, Min is 1/2 */
#define MAX_MULTI (2LL << MULTI_SHIFT)
#define MIN_MULTI (1LL << (MULTI_SHIFT-1))
struct sched_clock_data {
/*
* Raw spinlock - this is a special case: this might be called
@@ -40,11 +48,15 @@ struct sched_clock_data {
*/
raw_spinlock_t lock;
unsigned long prev_jiffies;
unsigned long tick_jiffies;
u64 prev_raw;
u64 tick_raw;
u64 tick_gtod;
u64 clock;
s64 multi;
#ifdef CONFIG_NO_HZ
int check_max;
#endif
};
static DEFINE_PER_CPU_SHARED_ALIGNED(struct sched_clock_data, sched_clock_data);
@@ -71,41 +83,91 @@ void sched_clock_init(void)
struct sched_clock_data *scd = cpu_sdc(cpu);
scd->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
scd->prev_jiffies = now_jiffies;
scd->tick_jiffies = now_jiffies;
scd->prev_raw = 0;
scd->tick_raw = 0;
scd->tick_gtod = ktime_now;
scd->clock = ktime_now;
scd->multi = 1 << MULTI_SHIFT;
#ifdef CONFIG_NO_HZ
scd->check_max = 1;
#endif
}
sched_clock_running = 1;
}
#ifdef CONFIG_NO_HZ
/*
* The dynamic ticks makes the delta jiffies inaccurate. This
* prevents us from checking the maximum time update.
* Disable the maximum check during stopped ticks.
*/
void sched_clock_tick_stop(int cpu)
{
struct sched_clock_data *scd = cpu_sdc(cpu);
scd->check_max = 0;
}
void sched_clock_tick_start(int cpu)
{
struct sched_clock_data *scd = cpu_sdc(cpu);
scd->check_max = 1;
}
static int check_max(struct sched_clock_data *scd)
{
return scd->check_max;
}
#else
static int check_max(struct sched_clock_data *scd)
{
return 1;
}
#endif /* CONFIG_NO_HZ */
/*
* update the percpu scd from the raw @now value
*
* - filter out backward motion
* - use jiffies to generate a min,max window to clip the raw values
*/
static void __update_sched_clock(struct sched_clock_data *scd, u64 now)
static void __update_sched_clock(struct sched_clock_data *scd, u64 now, u64 *time)
{
unsigned long now_jiffies = jiffies;
long delta_jiffies = now_jiffies - scd->prev_jiffies;
long delta_jiffies = now_jiffies - scd->tick_jiffies;
u64 clock = scd->clock;
u64 min_clock, max_clock;
s64 delta = now - scd->prev_raw;
WARN_ON_ONCE(!irqs_disabled());
min_clock = scd->tick_gtod + delta_jiffies * TICK_NSEC;
/*
* At schedule tick the clock can be just under the gtod. We don't
* want to push it too prematurely.
*/
min_clock = scd->tick_gtod + (delta_jiffies * TICK_NSEC);
if (min_clock > TICK_NSEC)
min_clock -= TICK_NSEC / 2;
if (unlikely(delta < 0)) {
clock++;
goto out;
}
max_clock = min_clock + TICK_NSEC;
/*
* The clock must stay within a jiffie of the gtod.
* But since we may be at the start of a jiffy or the end of one
* we add another jiffy buffer.
*/
max_clock = scd->tick_gtod + (2 + delta_jiffies) * TICK_NSEC;
if (unlikely(clock + delta > max_clock)) {
delta *= scd->multi;
delta >>= MULTI_SHIFT;
if (unlikely(clock + delta > max_clock) && check_max(scd)) {
if (clock < max_clock)
clock = max_clock;
else
@@ -118,9 +180,12 @@ static void __update_sched_clock(struct sched_clock_data *scd, u64 now)
if (unlikely(clock < min_clock))
clock = min_clock;
scd->prev_raw = now;
scd->prev_jiffies = now_jiffies;
scd->clock = clock;
if (time)
*time = clock;
else {
scd->prev_raw = now;
scd->clock = clock;
}
}
static void lock_double_clock(struct sched_clock_data *data1,
@@ -160,25 +225,30 @@ u64 sched_clock_cpu(int cpu)
now -= my_scd->tick_raw;
now += scd->tick_raw;
now -= my_scd->tick_gtod;
now += scd->tick_gtod;
now += my_scd->tick_gtod;
now -= scd->tick_gtod;
__raw_spin_unlock(&my_scd->lock);
__update_sched_clock(scd, now, &clock);
__raw_spin_unlock(&scd->lock);
} else {
__raw_spin_lock(&scd->lock);
__update_sched_clock(scd, now, NULL);
clock = scd->clock;
__raw_spin_unlock(&scd->lock);
}
__update_sched_clock(scd, now);
clock = scd->clock;
__raw_spin_unlock(&scd->lock);
return clock;
}
void sched_clock_tick(void)
{
struct sched_clock_data *scd = this_scd();
unsigned long now_jiffies = jiffies;
s64 mult, delta_gtod, delta_raw;
u64 now, now_gtod;
if (unlikely(!sched_clock_running))
@@ -186,18 +256,33 @@ void sched_clock_tick(void)
WARN_ON_ONCE(!irqs_disabled());
now = sched_clock();
now_gtod = ktime_to_ns(ktime_get());
now = sched_clock();
__raw_spin_lock(&scd->lock);
__update_sched_clock(scd, now);
__update_sched_clock(scd, now, NULL);
/*
* update tick_gtod after __update_sched_clock() because that will
* already observe 1 new jiffy; adding a new tick_gtod to that would
* increase the clock 2 jiffies.
*/
delta_gtod = now_gtod - scd->tick_gtod;
delta_raw = now - scd->tick_raw;
if ((long)delta_raw > 0) {
mult = delta_gtod << MULTI_SHIFT;
do_div(mult, delta_raw);
scd->multi = mult;
if (scd->multi > MAX_MULTI)
scd->multi = MAX_MULTI;
else if (scd->multi < MIN_MULTI)
scd->multi = MIN_MULTI;
} else
scd->multi = 1 << MULTI_SHIFT;
scd->tick_raw = now;
scd->tick_gtod = now_gtod;
scd->tick_jiffies = now_jiffies;
__raw_spin_unlock(&scd->lock);
}
@@ -227,6 +312,7 @@ void sched_clock_idle_wakeup_event(u64 delta_ns)
__raw_spin_lock(&scd->lock);
scd->prev_raw = now;
scd->clock += delta_ns;
scd->multi = 1 << MULTI_SHIFT;
__raw_spin_unlock(&scd->lock);
touch_softlockup_watchdog();
@@ -244,3 +330,16 @@ unsigned long long __attribute__((weak)) sched_clock(void)
{
return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ);
}
unsigned long long cpu_clock(int cpu)
{
unsigned long long clock;
unsigned long flags;
local_irq_save(flags);
clock = sched_clock_cpu(cpu);
local_irq_restore(flags);
return clock;
}
EXPORT_SYMBOL_GPL(cpu_clock);
kernel/sched_cpupri.c
+174
View File
@@ -0,0 +1,174 @@
/*
* kernel/sched_cpupri.c
*
* CPU priority management
*
* Copyright (C) 2007-2008 Novell
*
* Author: Gregory Haskins <ghaskins@novell.com>
*
* This code tracks the priority of each CPU so that global migration
* decisions are easy to calculate. Each CPU can be in a state as follows:
*
* (INVALID), IDLE, NORMAL, RT1, ... RT99
*
* 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
* 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
* worst case complexity of O(min(102, nr_domcpus)), though the scenario that
* yields the worst case search is fairly contrived.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; version 2
* of the License.
*/
#include "sched_cpupri.h"
/* Convert between a 140 based task->prio, and our 102 based cpupri */
static int convert_prio(int prio)
{
int cpupri;
if (prio == CPUPRI_INVALID)
cpupri = CPUPRI_INVALID;
else if (prio == MAX_PRIO)
cpupri = CPUPRI_IDLE;
else if (prio >= MAX_RT_PRIO)
cpupri = CPUPRI_NORMAL;
else
cpupri = MAX_RT_PRIO - prio + 1;
return cpupri;
}
#define for_each_cpupri_active(array, idx) \
for (idx = find_first_bit(array, CPUPRI_NR_PRIORITIES); \
idx < CPUPRI_NR_PRIORITIES; \
idx = find_next_bit(array, CPUPRI_NR_PRIORITIES, idx+1))
/**
* cpupri_find - find the best (lowest-pri) CPU in the system
* @cp: The cpupri context
* @p: The task
* @lowest_mask: A mask to fill in with selected CPUs
*
* Note: This function returns the recommended CPUs as calculated during the
* current invokation. By the time the call returns, the CPUs may have in
* fact changed priorities any number of times. While not ideal, it is not
* an issue of correctness since the normal rebalancer logic will correct
* any discrepancies created by racing against the uncertainty of the current
* priority configuration.
*
* Returns: (int)bool - CPUs were found
*/
int cpupri_find(struct cpupri *cp, struct task_struct *p,
cpumask_t *lowest_mask)
{
int idx = 0;
int task_pri = convert_prio(p->prio);
for_each_cpupri_active(cp->pri_active, idx) {
struct cpupri_vec *vec = &cp->pri_to_cpu[idx];
cpumask_t mask;
if (idx >= task_pri)
break;
cpus_and(mask, p->cpus_allowed, vec->mask);
if (cpus_empty(mask))
continue;
*lowest_mask = mask;
return 1;
}
return 0;
}
/**
* cpupri_set - update the cpu priority setting
* @cp: The cpupri context
* @cpu: The target cpu
* @pri: The priority (INVALID-RT99) to assign to this CPU
*
* Note: Assumes cpu_rq(cpu)->lock is locked
*
* Returns: (void)
*/
void cpupri_set(struct cpupri *cp, int cpu, int newpri)
{
int *currpri = &cp->cpu_to_pri[cpu];
int oldpri = *currpri;
unsigned long flags;
newpri = convert_prio(newpri);
BUG_ON(newpri >= CPUPRI_NR_PRIORITIES);
if (newpri == oldpri)
return;
/*
* If the cpu was currently mapped to a different value, we
* first need to unmap the old value
*/
if (likely(oldpri != CPUPRI_INVALID)) {
struct cpupri_vec *vec = &cp->pri_to_cpu[oldpri];
spin_lock_irqsave(&vec->lock, flags);
vec->count--;
if (!vec->count)
clear_bit(oldpri, cp->pri_active);
cpu_clear(cpu, vec->mask);
spin_unlock_irqrestore(&vec->lock, flags);
}
if (likely(newpri != CPUPRI_INVALID)) {
struct cpupri_vec *vec = &cp->pri_to_cpu[newpri];
spin_lock_irqsave(&vec->lock, flags);
cpu_set(cpu, vec->mask);
vec->count++;
if (vec->count == 1)
set_bit(newpri, cp->pri_active);
spin_unlock_irqrestore(&vec->lock, flags);
}
*currpri = newpri;
}
/**
* cpupri_init - initialize the cpupri structure
* @cp: The cpupri context
*
* Returns: (void)
*/
void cpupri_init(struct cpupri *cp)
{
int i;
memset(cp, 0, sizeof(*cp));
for (i = 0; i < CPUPRI_NR_PRIORITIES; i++) {
struct cpupri_vec *vec = &cp->pri_to_cpu[i];
spin_lock_init(&vec->lock);
vec->count = 0;
cpus_clear(vec->mask);
}
for_each_possible_cpu(i)
cp->cpu_to_pri[i] = CPUPRI_INVALID;
}
kernel/sched_cpupri.h
+36
View File
@@ -0,0 +1,36 @@
#ifndef _LINUX_CPUPRI_H
#define _LINUX_CPUPRI_H
#include <linux/sched.h>
#define CPUPRI_NR_PRIORITIES (MAX_RT_PRIO + 2)
#define CPUPRI_NR_PRI_WORDS BITS_TO_LONGS(CPUPRI_NR_PRIORITIES)
#define CPUPRI_INVALID -1
#define CPUPRI_IDLE 0
#define CPUPRI_NORMAL 1
/* values 2-101 are RT priorities 0-99 */
struct cpupri_vec {
spinlock_t lock;
int count;
cpumask_t mask;
};
struct cpupri {
struct cpupri_vec pri_to_cpu[CPUPRI_NR_PRIORITIES];
long pri_active[CPUPRI_NR_PRI_WORDS];
int cpu_to_pri[NR_CPUS];
};
#ifdef CONFIG_SMP
int cpupri_find(struct cpupri *cp,
struct task_struct *p, cpumask_t *lowest_mask);
void cpupri_set(struct cpupri *cp, int cpu, int pri);
void cpupri_init(struct cpupri *cp);
#else
#define cpupri_set(cp, cpu, pri) do { } while (0)
#define cpupri_init() do { } while (0)
#endif
#endif /* _LINUX_CPUPRI_H */
kernel/sched_debug.c
+59 -5
View File
@@ -119,9 +119,7 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
struct sched_entity *last;
unsigned long flags;
#if !defined(CONFIG_CGROUP_SCHED) || !defined(CONFIG_USER_SCHED)
SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu);
#else
#if defined(CONFIG_CGROUP_SCHED) && defined(CONFIG_FAIR_GROUP_SCHED)
char path[128] = "";
struct cgroup *cgroup = NULL;
struct task_group *tg = cfs_rq->tg;
@@ -133,6 +131,8 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
cgroup_path(cgroup, path, sizeof(path));
SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, path);
#else
SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu);
#endif
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "exec_clock",
@@ -162,11 +162,64 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
SEQ_printf(m, " .%-30s: %ld\n", "nr_running", cfs_rq->nr_running);
SEQ_printf(m, " .%-30s: %ld\n", "load", cfs_rq->load.weight);
#ifdef CONFIG_SCHEDSTATS
SEQ_printf(m, " .%-30s: %d\n", "bkl_count",
rq->bkl_count);
#define P(n) SEQ_printf(m, " .%-30s: %d\n", #n, rq->n);
P(yld_exp_empty);
P(yld_act_empty);
P(yld_both_empty);
P(yld_count);
P(sched_switch);
P(sched_count);
P(sched_goidle);
P(ttwu_count);
P(ttwu_local);
P(bkl_count);
#undef P
#endif
SEQ_printf(m, " .%-30s: %ld\n", "nr_spread_over",
cfs_rq->nr_spread_over);
#ifdef CONFIG_FAIR_GROUP_SCHED
#ifdef CONFIG_SMP
SEQ_printf(m, " .%-30s: %lu\n", "shares", cfs_rq->shares);
#endif
#endif
}
void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
{
#if defined(CONFIG_CGROUP_SCHED) && defined(CONFIG_RT_GROUP_SCHED)
char path[128] = "";
struct cgroup *cgroup = NULL;
struct task_group *tg = rt_rq->tg;
if (tg)
cgroup = tg->css.cgroup;
if (cgroup)
cgroup_path(cgroup, path, sizeof(path));
SEQ_printf(m, "\nrt_rq[%d]:%s\n", cpu, path);
#else
SEQ_printf(m, "\nrt_rq[%d]:\n", cpu);
#endif
#define P(x) \
SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rt_rq->x))
#define PN(x) \
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rt_rq->x))
P(rt_nr_running);
P(rt_throttled);
PN(rt_time);
PN(rt_runtime);
#undef PN
#undef P
}
static void print_cpu(struct seq_file *m, int cpu)
@@ -208,6 +261,7 @@ static void print_cpu(struct seq_file *m, int cpu)
#undef PN
print_cfs_stats(m, cpu);
print_rt_stats(m, cpu);
print_rq(m, rq, cpu);
}
kernel/sched_fair.c
+290 -123
View File
@@ -63,13 +63,13 @@ unsigned int __read_mostly sysctl_sched_compat_yield;
/*
* SCHED_OTHER wake-up granularity.
* (default: 10 msec * (1 + ilog(ncpus)), units: nanoseconds)
* (default: 5 msec * (1 + ilog(ncpus)), units: nanoseconds)
*
* This option delays the preemption effects of decoupled workloads
* and reduces their over-scheduling. Synchronous workloads will still
* have immediate wakeup/sleep latencies.
*/
unsigned int sysctl_sched_wakeup_granularity = 10000000UL;
unsigned int sysctl_sched_wakeup_granularity = 5000000UL;
const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
@@ -333,6 +333,34 @@ int sched_nr_latency_handler(struct ctl_table *table, int write,
}
#endif
/*
* delta *= w / rw
*/
static inline unsigned long
calc_delta_weight(unsigned long delta, struct sched_entity *se)
{
for_each_sched_entity(se) {
delta = calc_delta_mine(delta,
se->load.weight, &cfs_rq_of(se)->load);
}
return delta;
}
/*
* delta *= rw / w
*/
static inline unsigned long
calc_delta_fair(unsigned long delta, struct sched_entity *se)
{
for_each_sched_entity(se) {
delta = calc_delta_mine(delta,
cfs_rq_of(se)->load.weight, &se->load);
}
return delta;
}
/*
* The idea is to set a period in which each task runs once.
*
@@ -362,47 +390,80 @@ static u64 __sched_period(unsigned long nr_running)
*/
static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
u64 slice = __sched_period(cfs_rq->nr_running);
for_each_sched_entity(se) {
cfs_rq = cfs_rq_of(se);
slice *= se->load.weight;
do_div(slice, cfs_rq->load.weight);
}
return slice;
return calc_delta_weight(__sched_period(cfs_rq->nr_running), se);
}
/*
* We calculate the vruntime slice of a to be inserted task
*
* vs = s/w = p/rw
* vs = s*rw/w = p
*/
static u64 sched_vslice_add(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
unsigned long nr_running = cfs_rq->nr_running;
unsigned long weight;
u64 vslice;
if (!se->on_rq)
nr_running++;
vslice = __sched_period(nr_running);
return __sched_period(nr_running);
}
/*
* The goal of calc_delta_asym() is to be asymmetrically around NICE_0_LOAD, in
* that it favours >=0 over <0.
*
* -20 |
* |
* 0 --------+-------
* .'
* 19 .'
*
*/
static unsigned long
calc_delta_asym(unsigned long delta, struct sched_entity *se)
{
struct load_weight lw = {
.weight = NICE_0_LOAD,
.inv_weight = 1UL << (WMULT_SHIFT-NICE_0_SHIFT)
};
for_each_sched_entity(se) {
cfs_rq = cfs_rq_of(se);
struct load_weight *se_lw = &se->load;
unsigned long rw = cfs_rq_of(se)->load.weight;
weight = cfs_rq->load.weight;
if (!se->on_rq)
weight += se->load.weight;
#ifdef CONFIG_FAIR_SCHED_GROUP
struct cfs_rq *cfs_rq = se->my_q;
struct task_group *tg = NULL
vslice *= NICE_0_LOAD;
do_div(vslice, weight);
if (cfs_rq)
tg = cfs_rq->tg;
if (tg && tg->shares < NICE_0_LOAD) {
/*
* scale shares to what it would have been had
* tg->weight been NICE_0_LOAD:
*
* weight = 1024 * shares / tg->weight
*/
lw.weight *= se->load.weight;
lw.weight /= tg->shares;
lw.inv_weight = 0;
se_lw = &lw;
rw += lw.weight - se->load.weight;
} else
#endif
if (se->load.weight < NICE_0_LOAD) {
se_lw = &lw;
rw += NICE_0_LOAD - se->load.weight;
}
delta = calc_delta_mine(delta, rw, se_lw);
}
return vslice;
return delta;
}
/*
@@ -419,11 +480,7 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
curr->sum_exec_runtime += delta_exec;
schedstat_add(cfs_rq, exec_clock, delta_exec);
delta_exec_weighted = delta_exec;
if (unlikely(curr->load.weight != NICE_0_LOAD)) {
delta_exec_weighted = calc_delta_fair(delta_exec_weighted,
&curr->load);
}
delta_exec_weighted = calc_delta_fair(delta_exec, curr);
curr->vruntime += delta_exec_weighted;
}
@@ -510,10 +567,27 @@ update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
* Scheduling class queueing methods:
*/
#if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED
static void
add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight)
{
cfs_rq->task_weight += weight;
}
#else
static inline void
add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight)
{
}
#endif
static void
account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
update_load_add(&cfs_rq->load, se->load.weight);
if (!parent_entity(se))
inc_cpu_load(rq_of(cfs_rq), se->load.weight);
if (entity_is_task(se))
add_cfs_task_weight(cfs_rq, se->load.weight);
cfs_rq->nr_running++;
se->on_rq = 1;
list_add(&se->group_node, &cfs_rq->tasks);
@@ -523,6 +597,10 @@ static void
account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
update_load_sub(&cfs_rq->load, se->load.weight);
if (!parent_entity(se))
dec_cpu_load(rq_of(cfs_rq), se->load.weight);
if (entity_is_task(se))
add_cfs_task_weight(cfs_rq, -se->load.weight);
cfs_rq->nr_running--;
se->on_rq = 0;
list_del_init(&se->group_node);
@@ -609,8 +687,17 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
if (!initial) {
/* sleeps upto a single latency don't count. */
if (sched_feat(NEW_FAIR_SLEEPERS))
vruntime -= sysctl_sched_latency;
if (sched_feat(NEW_FAIR_SLEEPERS)) {
unsigned long thresh = sysctl_sched_latency;
/*
* convert the sleeper threshold into virtual time
*/
if (sched_feat(NORMALIZED_SLEEPER))
thresh = calc_delta_fair(thresh, se);
vruntime -= thresh;
}
/* ensure we never gain time by being placed backwards. */
vruntime = max_vruntime(se->vruntime, vruntime);
@@ -639,21 +726,6 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup)
__enqueue_entity(cfs_rq, se);
}
static void update_avg(u64 *avg, u64 sample)
{
s64 diff = sample - *avg;
*avg += diff >> 3;
}
static void update_avg_stats(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
if (!se->last_wakeup)
return;
update_avg(&se->avg_overlap, se->sum_exec_runtime - se->last_wakeup);
se->last_wakeup = 0;
}
static void
dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
{
@@ -664,7 +736,6 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
update_stats_dequeue(cfs_rq, se);
if (sleep) {
update_avg_stats(cfs_rq, se);
#ifdef CONFIG_SCHEDSTATS
if (entity_is_task(se)) {
struct task_struct *tsk = task_of(se);
@@ -726,17 +797,16 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
se->prev_sum_exec_runtime = se->sum_exec_runtime;
}
static int
wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se);
static struct sched_entity *
pick_next(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
if (!cfs_rq->next)
return se;
struct rq *rq = rq_of(cfs_rq);
u64 pair_slice = rq->clock - cfs_rq->pair_start;
if (wakeup_preempt_entity(cfs_rq->next, se) != 0)
if (!cfs_rq->next || pair_slice > sched_slice(cfs_rq, cfs_rq->next)) {
cfs_rq->pair_start = rq->clock;
return se;
}
return cfs_rq->next;
}
@@ -835,7 +905,7 @@ static void hrtick_start_fair(struct rq *rq, struct task_struct *p)
hrtick_start(rq, delta, requeue);
}
}
#else
#else /* !CONFIG_SCHED_HRTICK */
static inline void
hrtick_start_fair(struct rq *rq, struct task_struct *p)
{
@@ -976,7 +1046,7 @@ static int wake_idle(int cpu, struct task_struct *p)
}
return cpu;
}
#else
#else /* !ARCH_HAS_SCHED_WAKE_IDLE*/
static inline int wake_idle(int cpu, struct task_struct *p)
{
return cpu;
@@ -987,6 +1057,89 @@ static inline int wake_idle(int cpu, struct task_struct *p)
static const struct sched_class fair_sched_class;
#ifdef CONFIG_FAIR_GROUP_SCHED
/*
* effective_load() calculates the load change as seen from the root_task_group
*
* Adding load to a group doesn't make a group heavier, but can cause movement
* of group shares between cpus. Assuming the shares were perfectly aligned one
* can calculate the shift in shares.
*
* The problem is that perfectly aligning the shares is rather expensive, hence
* we try to avoid doing that too often - see update_shares(), which ratelimits
* this change.
*
* We compensate this by not only taking the current delta into account, but
* also considering the delta between when the shares were last adjusted and
* now.
*
* We still saw a performance dip, some tracing learned us that between
* cgroup:/ and cgroup:/foo balancing the number of affine wakeups increased
* significantly. Therefore try to bias the error in direction of failing
* the affine wakeup.
*
*/
static long effective_load(struct task_group *tg, int cpu,
long wl, long wg)
{
struct sched_entity *se = tg->se[cpu];
long more_w;
if (!tg->parent)
return wl;
/*
* By not taking the decrease of shares on the other cpu into
* account our error leans towards reducing the affine wakeups.
*/
if (!wl && sched_feat(ASYM_EFF_LOAD))
return wl;
/*
* Instead of using this increment, also add the difference
* between when the shares were last updated and now.
*/
more_w = se->my_q->load.weight - se->my_q->rq_weight;
wl += more_w;
wg += more_w;
for_each_sched_entity(se) {
#define D(n) (likely(n) ? (n) : 1)
long S, rw, s, a, b;
S = se->my_q->tg->shares;
s = se->my_q->shares;
rw = se->my_q->rq_weight;
a = S*(rw + wl);
b = S*rw + s*wg;
wl = s*(a-b)/D(b);
/*
* Assume the group is already running and will
* thus already be accounted for in the weight.
*
* That is, moving shares between CPUs, does not
* alter the group weight.
*/
wg = 0;
#undef D
}
return wl;
}
#else
static inline unsigned long effective_load(struct task_group *tg, int cpu,
unsigned long wl, unsigned long wg)
{
return wl;
}
#endif
static int
wake_affine(struct rq *rq, struct sched_domain *this_sd, struct rq *this_rq,
struct task_struct *p, int prev_cpu, int this_cpu, int sync,
@@ -994,8 +1147,10 @@ wake_affine(struct rq *rq, struct sched_domain *this_sd, struct rq *this_rq,
unsigned int imbalance)
{
struct task_struct *curr = this_rq->curr;
struct task_group *tg;
unsigned long tl = this_load;
unsigned long tl_per_task;
unsigned long weight;
int balanced;
if (!(this_sd->flags & SD_WAKE_AFFINE) || !sched_feat(AFFINE_WAKEUPS))
@@ -1006,19 +1161,28 @@ wake_affine(struct rq *rq, struct sched_domain *this_sd, struct rq *this_rq,
* effect of the currently running task from the load
* of the current CPU:
*/
if (sync)
tl -= current->se.load.weight;
if (sync) {
tg = task_group(current);
weight = current->se.load.weight;
balanced = 100*(tl + p->se.load.weight) <= imbalance*load;
tl += effective_load(tg, this_cpu, -weight, -weight);
load += effective_load(tg, prev_cpu, 0, -weight);
}
tg = task_group(p);
weight = p->se.load.weight;
balanced = 100*(tl + effective_load(tg, this_cpu, weight, weight)) <=
imbalance*(load + effective_load(tg, prev_cpu, 0, weight));
/*
* If the currently running task will sleep within
* a reasonable amount of time then attract this newly
* woken task:
*/
if (sync && balanced && curr->sched_class == &fair_sched_class) {
if (sync && balanced) {
if (curr->se.avg_overlap < sysctl_sched_migration_cost &&
p->se.avg_overlap < sysctl_sched_migration_cost)
p->se.avg_overlap < sysctl_sched_migration_cost)
return 1;
}
@@ -1111,11 +1275,13 @@ static unsigned long wakeup_gran(struct sched_entity *se)
unsigned long gran = sysctl_sched_wakeup_granularity;
/*
* More easily preempt - nice tasks, while not making
* it harder for + nice tasks.
* More easily preempt - nice tasks, while not making it harder for
* + nice tasks.
*/
if (unlikely(se->load.weight > NICE_0_LOAD))
gran = calc_delta_fair(gran, &se->load);
if (sched_feat(ASYM_GRAN))
gran = calc_delta_asym(sysctl_sched_wakeup_granularity, se);
else
gran = calc_delta_fair(sysctl_sched_wakeup_granularity, se);
return gran;
}
@@ -1177,7 +1343,6 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p)
return;
}
se->last_wakeup = se->sum_exec_runtime;
if (unlikely(se == pse))
return;
@@ -1275,23 +1440,18 @@ __load_balance_iterator(struct cfs_rq *cfs_rq, struct list_head *next)
struct task_struct *p = NULL;
struct sched_entity *se;
if (next == &cfs_rq->tasks)
return NULL;
/* Skip over entities that are not tasks */
do {
while (next != &cfs_rq->tasks) {
se = list_entry(next, struct sched_entity, group_node);
next = next->next;
} while (next != &cfs_rq->tasks && !entity_is_task(se));
if (next == &cfs_rq->tasks)
return NULL;
/* Skip over entities that are not tasks */
if (entity_is_task(se)) {
p = task_of(se);
break;
}
}
cfs_rq->balance_iterator = next;
if (entity_is_task(se))
p = task_of(se);
return p;
}
@@ -1309,75 +1469,82 @@ static struct task_struct *load_balance_next_fair(void *arg)
return __load_balance_iterator(cfs_rq, cfs_rq->balance_iterator);
}
#ifdef CONFIG_FAIR_GROUP_SCHED
static int cfs_rq_best_prio(struct cfs_rq *cfs_rq)
static unsigned long
__load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
unsigned long max_load_move, struct sched_domain *sd,
enum cpu_idle_type idle, int *all_pinned, int *this_best_prio,
struct cfs_rq *cfs_rq)
{
struct sched_entity *curr;
struct task_struct *p;
struct rq_iterator cfs_rq_iterator;
if (!cfs_rq->nr_running || !first_fair(cfs_rq))
return MAX_PRIO;
cfs_rq_iterator.start = load_balance_start_fair;
cfs_rq_iterator.next = load_balance_next_fair;
cfs_rq_iterator.arg = cfs_rq;
curr = cfs_rq->curr;
if (!curr)
curr = __pick_next_entity(cfs_rq);
p = task_of(curr);
return p->prio;
return balance_tasks(this_rq, this_cpu, busiest,
max_load_move, sd, idle, all_pinned,
this_best_prio, &cfs_rq_iterator);
}
#endif
#ifdef CONFIG_FAIR_GROUP_SCHED
static unsigned long
load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
unsigned long max_load_move,
struct sched_domain *sd, enum cpu_idle_type idle,
int *all_pinned, int *this_best_prio)
{
struct cfs_rq *busy_cfs_rq;
long rem_load_move = max_load_move;
struct rq_iterator cfs_rq_iterator;
int busiest_cpu = cpu_of(busiest);
struct task_group *tg;
cfs_rq_iterator.start = load_balance_start_fair;
cfs_rq_iterator.next = load_balance_next_fair;
rcu_read_lock();
update_h_load(busiest_cpu);
for_each_leaf_cfs_rq(busiest, busy_cfs_rq) {
#ifdef CONFIG_FAIR_GROUP_SCHED
struct cfs_rq *this_cfs_rq;
long imbalance;
unsigned long maxload;
list_for_each_entry(tg, &task_groups, list) {
struct cfs_rq *busiest_cfs_rq = tg->cfs_rq[busiest_cpu];
unsigned long busiest_h_load = busiest_cfs_rq->h_load;
unsigned long busiest_weight = busiest_cfs_rq->load.weight;
u64 rem_load, moved_load;
this_cfs_rq = cpu_cfs_rq(busy_cfs_rq, this_cpu);
imbalance = busy_cfs_rq->load.weight - this_cfs_rq->load.weight;
/* Don't pull if this_cfs_rq has more load than busy_cfs_rq */
if (imbalance <= 0)
/*
* empty group
*/
if (!busiest_cfs_rq->task_weight)
continue;
/* Don't pull more than imbalance/2 */
imbalance /= 2;
maxload = min(rem_load_move, imbalance);
rem_load = (u64)rem_load_move * busiest_weight;
rem_load = div_u64(rem_load, busiest_h_load + 1);
*this_best_prio = cfs_rq_best_prio(this_cfs_rq);
#else
# define maxload rem_load_move
#endif
/*
* pass busy_cfs_rq argument into
* load_balance_[start|next]_fair iterators
*/
cfs_rq_iterator.arg = busy_cfs_rq;
rem_load_move -= balance_tasks(this_rq, this_cpu, busiest,
maxload, sd, idle, all_pinned,
this_best_prio,
&cfs_rq_iterator);
moved_load = __load_balance_fair(this_rq, this_cpu, busiest,
rem_load, sd, idle, all_pinned, this_best_prio,
tg->cfs_rq[busiest_cpu]);
if (rem_load_move <= 0)
if (!moved_load)
continue;
moved_load *= busiest_h_load;
moved_load = div_u64(moved_load, busiest_weight + 1);
rem_load_move -= moved_load;
if (rem_load_move < 0)
break;
}
rcu_read_unlock();
return max_load_move - rem_load_move;
}
#else
static unsigned long
load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
unsigned long max_load_move,
struct sched_domain *sd, enum cpu_idle_type idle,
int *all_pinned, int *this_best_prio)
{
return __load_balance_fair(this_rq, this_cpu, busiest,
max_load_move, sd, idle, all_pinned,
this_best_prio, &busiest->cfs);
}
#endif
static int
move_one_task_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
@@ -1402,7 +1569,7 @@ move_one_task_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
return 0;
}
#endif
#endif /* CONFIG_SMP */
/*
* scheduler tick hitting a task of our scheduling class:
kernel/sched_features.h
+5 -2
View File
@@ -1,4 +1,5 @@
SCHED_FEAT(NEW_FAIR_SLEEPERS, 1)
SCHED_FEAT(NORMALIZED_SLEEPER, 1)
SCHED_FEAT(WAKEUP_PREEMPT, 1)
SCHED_FEAT(START_DEBIT, 1)
SCHED_FEAT(AFFINE_WAKEUPS, 1)
@@ -6,5 +7,7 @@ SCHED_FEAT(CACHE_HOT_BUDDY, 1)
SCHED_FEAT(SYNC_WAKEUPS, 1)
SCHED_FEAT(HRTICK, 1)
SCHED_FEAT(DOUBLE_TICK, 0)
SCHED_FEAT(NORMALIZED_SLEEPER, 1)
SCHED_FEAT(DEADLINE, 1)
SCHED_FEAT(ASYM_GRAN, 1)
SCHED_FEAT(LB_BIAS, 0)
SCHED_FEAT(LB_WAKEUP_UPDATE, 1)
SCHED_FEAT(ASYM_EFF_LOAD, 1)
kernel/sched_rt.c
+264 -141
View File
@@ -12,6 +12,9 @@ static inline int rt_overloaded(struct rq *rq)
static inline void rt_set_overload(struct rq *rq)
{
if (!rq->online)
return;
cpu_set(rq->cpu, rq->rd->rto_mask);
/*
* Make sure the mask is visible before we set
@@ -26,6 +29,9 @@ static inline void rt_set_overload(struct rq *rq)
static inline void rt_clear_overload(struct rq *rq)
{
if (!rq->online)
return;
/* the order here really doesn't matter */
atomic_dec(&rq->rd->rto_count);
cpu_clear(rq->cpu, rq->rd->rto_mask);
@@ -155,7 +161,7 @@ static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)
return &rt_rq->tg->rt_bandwidth;
}
#else
#else /* !CONFIG_RT_GROUP_SCHED */
static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)
{
@@ -220,7 +226,160 @@ static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)
return &def_rt_bandwidth;
}
#endif
#endif /* CONFIG_RT_GROUP_SCHED */
#ifdef CONFIG_SMP
static int do_balance_runtime(struct rt_rq *rt_rq)
{
struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
struct root_domain *rd = cpu_rq(smp_processor_id())->rd;
int i, weight, more = 0;
u64 rt_period;
weight = cpus_weight(rd->span);
spin_lock(&rt_b->rt_runtime_lock);
rt_period = ktime_to_ns(rt_b->rt_period);
for_each_cpu_mask(i, rd->span) {
struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
s64 diff;
if (iter == rt_rq)
continue;
spin_lock(&iter->rt_runtime_lock);
if (iter->rt_runtime == RUNTIME_INF)
goto next;
diff = iter->rt_runtime - iter->rt_time;
if (diff > 0) {
do_div(diff, weight);
if (rt_rq->rt_runtime + diff > rt_period)
diff = rt_period - rt_rq->rt_runtime;
iter->rt_runtime -= diff;
rt_rq->rt_runtime += diff;
more = 1;
if (rt_rq->rt_runtime == rt_period) {
spin_unlock(&iter->rt_runtime_lock);
break;
}
}
next:
spin_unlock(&iter->rt_runtime_lock);
}
spin_unlock(&rt_b->rt_runtime_lock);
return more;
}
static void __disable_runtime(struct rq *rq)
{
struct root_domain *rd = rq->rd;
struct rt_rq *rt_rq;
if (unlikely(!scheduler_running))
return;
for_each_leaf_rt_rq(rt_rq, rq) {
struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
s64 want;
int i;
spin_lock(&rt_b->rt_runtime_lock);
spin_lock(&rt_rq->rt_runtime_lock);
if (rt_rq->rt_runtime == RUNTIME_INF ||
rt_rq->rt_runtime == rt_b->rt_runtime)
goto balanced;
spin_unlock(&rt_rq->rt_runtime_lock);
want = rt_b->rt_runtime - rt_rq->rt_runtime;
for_each_cpu_mask(i, rd->span) {
struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
s64 diff;
if (iter == rt_rq)
continue;
spin_lock(&iter->rt_runtime_lock);
if (want > 0) {
diff = min_t(s64, iter->rt_runtime, want);
iter->rt_runtime -= diff;
want -= diff;
} else {
iter->rt_runtime -= want;
want -= want;
}
spin_unlock(&iter->rt_runtime_lock);
if (!want)
break;
}
spin_lock(&rt_rq->rt_runtime_lock);
BUG_ON(want);
balanced:
rt_rq->rt_runtime = RUNTIME_INF;
spin_unlock(&rt_rq->rt_runtime_lock);
spin_unlock(&rt_b->rt_runtime_lock);
}
}
static void disable_runtime(struct rq *rq)
{
unsigned long flags;
spin_lock_irqsave(&rq->lock, flags);
__disable_runtime(rq);
spin_unlock_irqrestore(&rq->lock, flags);
}
static void __enable_runtime(struct rq *rq)
{
struct rt_rq *rt_rq;
if (unlikely(!scheduler_running))
return;
for_each_leaf_rt_rq(rt_rq, rq) {
struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
spin_lock(&rt_b->rt_runtime_lock);
spin_lock(&rt_rq->rt_runtime_lock);
rt_rq->rt_runtime = rt_b->rt_runtime;
rt_rq->rt_time = 0;
spin_unlock(&rt_rq->rt_runtime_lock);
spin_unlock(&rt_b->rt_runtime_lock);
}
}
static void enable_runtime(struct rq *rq)
{
unsigned long flags;
spin_lock_irqsave(&rq->lock, flags);
__enable_runtime(rq);
spin_unlock_irqrestore(&rq->lock, flags);
}
static int balance_runtime(struct rt_rq *rt_rq)
{
int more = 0;
if (rt_rq->rt_time > rt_rq->rt_runtime) {
spin_unlock(&rt_rq->rt_runtime_lock);
more = do_balance_runtime(rt_rq);
spin_lock(&rt_rq->rt_runtime_lock);
}
return more;
}
#else /* !CONFIG_SMP */
static inline int balance_runtime(struct rt_rq *rt_rq)
{
return 0;
}
#endif /* CONFIG_SMP */
static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
{
@@ -241,6 +400,8 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
u64 runtime;
spin_lock(&rt_rq->rt_runtime_lock);
if (rt_rq->rt_throttled)
balance_runtime(rt_rq);
runtime = rt_rq->rt_runtime;
rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime);
if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) {
@@ -261,47 +422,6 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
return idle;
}
#ifdef CONFIG_SMP
static int balance_runtime(struct rt_rq *rt_rq)
{
struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
struct root_domain *rd = cpu_rq(smp_processor_id())->rd;
int i, weight, more = 0;
u64 rt_period;
weight = cpus_weight(rd->span);
spin_lock(&rt_b->rt_runtime_lock);
rt_period = ktime_to_ns(rt_b->rt_period);
for_each_cpu_mask(i, rd->span) {
struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
s64 diff;
if (iter == rt_rq)
continue;
spin_lock(&iter->rt_runtime_lock);
diff = iter->rt_runtime - iter->rt_time;
if (diff > 0) {
do_div(diff, weight);
if (rt_rq->rt_runtime + diff > rt_period)
diff = rt_period - rt_rq->rt_runtime;
iter->rt_runtime -= diff;
rt_rq->rt_runtime += diff;
more = 1;
if (rt_rq->rt_runtime == rt_period) {
spin_unlock(&iter->rt_runtime_lock);
break;
}
}
spin_unlock(&iter->rt_runtime_lock);
}
spin_unlock(&rt_b->rt_runtime_lock);
return more;
}
#endif
static inline int rt_se_prio(struct sched_rt_entity *rt_se)
{
#ifdef CONFIG_RT_GROUP_SCHED
@@ -327,18 +447,10 @@ static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
if (sched_rt_runtime(rt_rq) >= sched_rt_period(rt_rq))
return 0;
#ifdef CONFIG_SMP
if (rt_rq->rt_time > runtime) {
int more;
spin_unlock(&rt_rq->rt_runtime_lock);
more = balance_runtime(rt_rq);
spin_lock(&rt_rq->rt_runtime_lock);
if (more)
runtime = sched_rt_runtime(rt_rq);
}
#endif
balance_runtime(rt_rq);
runtime = sched_rt_runtime(rt_rq);
if (runtime == RUNTIME_INF)
return 0;
if (rt_rq->rt_time > runtime) {
rt_rq->rt_throttled = 1;
@@ -392,12 +504,21 @@ void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
WARN_ON(!rt_prio(rt_se_prio(rt_se)));
rt_rq->rt_nr_running++;
#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
if (rt_se_prio(rt_se) < rt_rq->highest_prio)
if (rt_se_prio(rt_se) < rt_rq->highest_prio) {
struct rq *rq = rq_of_rt_rq(rt_rq);
rt_rq->highest_prio = rt_se_prio(rt_se);
#ifdef CONFIG_SMP
if (rq->online)
cpupri_set(&rq->rd->cpupri, rq->cpu,
rt_se_prio(rt_se));
#endif
}
#endif
#ifdef CONFIG_SMP
if (rt_se->nr_cpus_allowed > 1) {
struct rq *rq = rq_of_rt_rq(rt_rq);
rq->rt.rt_nr_migratory++;
}
@@ -417,6 +538,10 @@ void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
static inline
void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
{
#ifdef CONFIG_SMP
int highest_prio = rt_rq->highest_prio;
#endif
WARN_ON(!rt_prio(rt_se_prio(rt_se)));
WARN_ON(!rt_rq->rt_nr_running);
rt_rq->rt_nr_running--;
@@ -440,6 +565,14 @@ void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
rq->rt.rt_nr_migratory--;
}
if (rt_rq->highest_prio != highest_prio) {
struct rq *rq = rq_of_rt_rq(rt_rq);
if (rq->online)
cpupri_set(&rq->rd->cpupri, rq->cpu,
rt_rq->highest_prio);
}
update_rt_migration(rq_of_rt_rq(rt_rq));
#endif /* CONFIG_SMP */
#ifdef CONFIG_RT_GROUP_SCHED
@@ -455,6 +588,7 @@ static void __enqueue_rt_entity(struct sched_rt_entity *rt_se)
struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
struct rt_prio_array *array = &rt_rq->active;
struct rt_rq *group_rq = group_rt_rq(rt_se);
struct list_head *queue = array->queue + rt_se_prio(rt_se);
/*
* Don't enqueue the group if its throttled, or when empty.
@@ -465,7 +599,11 @@ static void __enqueue_rt_entity(struct sched_rt_entity *rt_se)
if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running))
return;
list_add_tail(&rt_se->run_list, array->queue + rt_se_prio(rt_se));
if (rt_se->nr_cpus_allowed == 1)
list_add(&rt_se->run_list, queue);
else
list_add_tail(&rt_se->run_list, queue);
__set_bit(rt_se_prio(rt_se), array->bitmap);
inc_rt_tasks(rt_se, rt_rq);
@@ -532,6 +670,8 @@ static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup)
rt_se->timeout = 0;
enqueue_rt_entity(rt_se);
inc_cpu_load(rq, p->se.load.weight);
}
static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
@@ -540,6 +680,8 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
update_curr_rt(rq);
dequeue_rt_entity(rt_se);
dec_cpu_load(rq, p->se.load.weight);
}
/*
@@ -550,10 +692,12 @@ static
void requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se)
{
struct rt_prio_array *array = &rt_rq->active;
struct list_head *queue = array->queue + rt_se_prio(rt_se);
if (on_rt_rq(rt_se))
list_move_tail(&rt_se->run_list, queue);
if (on_rt_rq(rt_se)) {
list_del_init(&rt_se->run_list);
list_add_tail(&rt_se->run_list,
array->queue + rt_se_prio(rt_se));
}
}
static void requeue_task_rt(struct rq *rq, struct task_struct *p)
@@ -616,8 +760,37 @@ static int select_task_rq_rt(struct task_struct *p, int sync)
*/
static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p)
{
if (p->prio < rq->curr->prio)
if (p->prio < rq->curr->prio) {
resched_task(rq->curr);
return;
}
#ifdef CONFIG_SMP
/*
* If:
*
* - the newly woken task is of equal priority to the current task
* - the newly woken task is non-migratable while current is migratable
* - current will be preempted on the next reschedule
*
* we should check to see if current can readily move to a different
* cpu. If so, we will reschedule to allow the push logic to try
* to move current somewhere else, making room for our non-migratable
* task.
*/
if((p->prio == rq->curr->prio)
&& p->rt.nr_cpus_allowed == 1
&& rq->curr->rt.nr_cpus_allowed != 1) {
cpumask_t mask;
if (cpupri_find(&rq->rd->cpupri, rq->curr, &mask))
/*
* There appears to be other cpus that can accept
* current, so lets reschedule to try and push it away
*/
resched_task(rq->curr);
}
#endif
}
static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq,
@@ -720,73 +893,6 @@ static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu)
static DEFINE_PER_CPU(cpumask_t, local_cpu_mask);
static int find_lowest_cpus(struct task_struct *task, cpumask_t *lowest_mask)
{
int lowest_prio = -1;
int lowest_cpu = -1;
int count = 0;
int cpu;
cpus_and(*lowest_mask, task_rq(task)->rd->online, task->cpus_allowed);
/*
* Scan each rq for the lowest prio.
*/
for_each_cpu_mask(cpu, *lowest_mask) {
struct rq *rq = cpu_rq(cpu);
/* We look for lowest RT prio or non-rt CPU */
if (rq->rt.highest_prio >= MAX_RT_PRIO) {
/*
* if we already found a low RT queue
* and now we found this non-rt queue
* clear the mask and set our bit.
* Otherwise just return the queue as is
* and the count==1 will cause the algorithm
* to use the first bit found.
*/
if (lowest_cpu != -1) {
cpus_clear(*lowest_mask);
cpu_set(rq->cpu, *lowest_mask);
}
return 1;
}
/* no locking for now */
if ((rq->rt.highest_prio > task->prio)
&& (rq->rt.highest_prio >= lowest_prio)) {
if (rq->rt.highest_prio > lowest_prio) {
/* new low - clear old data */
lowest_prio = rq->rt.highest_prio;
lowest_cpu = cpu;
count = 0;
}
count++;
} else
cpu_clear(cpu, *lowest_mask);
}
/*
* Clear out all the set bits that represent
* runqueues that were of higher prio than
* the lowest_prio.
*/
if (lowest_cpu > 0) {
/*
* Perhaps we could add another cpumask op to
* zero out bits. Like cpu_zero_bits(cpumask, nrbits);
* Then that could be optimized to use memset and such.
*/
for_each_cpu_mask(cpu, *lowest_mask) {
if (cpu >= lowest_cpu)
break;
cpu_clear(cpu, *lowest_mask);
}
}
return count;
}
static inline int pick_optimal_cpu(int this_cpu, cpumask_t *mask)
{
int first;
@@ -808,18 +914,13 @@ static int find_lowest_rq(struct task_struct *task)
cpumask_t *lowest_mask = &__get_cpu_var(local_cpu_mask);
int this_cpu = smp_processor_id();
int cpu = task_cpu(task);
int count = find_lowest_cpus(task, lowest_mask);
if (!count)
if (task->rt.nr_cpus_allowed == 1)
return -1; /* No other targets possible */
if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask))
return -1; /* No targets found */
/*
* There is no sense in performing an optimal search if only one
* target is found.
*/
if (count == 1)
return first_cpu(*lowest_mask);
/*
* At this point we have built a mask of cpus representing the
* lowest priority tasks in the system. Now we want to elect
@@ -1163,17 +1264,25 @@ static void set_cpus_allowed_rt(struct task_struct *p,
}
/* Assumes rq->lock is held */
static void join_domain_rt(struct rq *rq)
static void rq_online_rt(struct rq *rq)
{
if (rq->rt.overloaded)
rt_set_overload(rq);
__enable_runtime(rq);
cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio);
}
/* Assumes rq->lock is held */
static void leave_domain_rt(struct rq *rq)
static void rq_offline_rt(struct rq *rq)
{
if (rq->rt.overloaded)
rt_clear_overload(rq);
__disable_runtime(rq);
cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID);
}
/*
@@ -1336,8 +1445,8 @@ static const struct sched_class rt_sched_class = {
.load_balance = load_balance_rt,
.move_one_task = move_one_task_rt,
.set_cpus_allowed = set_cpus_allowed_rt,
.join_domain = join_domain_rt,
.leave_domain = leave_domain_rt,
.rq_online = rq_online_rt,
.rq_offline = rq_offline_rt,
.pre_schedule = pre_schedule_rt,
.post_schedule = post_schedule_rt,
.task_wake_up = task_wake_up_rt,
@@ -1350,3 +1459,17 @@ static const struct sched_class rt_sched_class = {
.prio_changed = prio_changed_rt,
.switched_to = switched_to_rt,
};
#ifdef CONFIG_SCHED_DEBUG
extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq);
static void print_rt_stats(struct seq_file *m, int cpu)
{
struct rt_rq *rt_rq;
rcu_read_lock();
for_each_leaf_rt_rq(rt_rq, cpu_rq(cpu))
print_rt_rq(m, cpu, rt_rq);
rcu_read_unlock();
}
#endif /* CONFIG_SCHED_DEBUG */
kernel/sched_stats.h
+33 -9
View File
@@ -118,6 +118,13 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta)
if (rq)
rq->rq_sched_info.cpu_time += delta;
}
static inline void
rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
{
if (rq)
rq->rq_sched_info.run_delay += delta;
}
# define schedstat_inc(rq, field) do { (rq)->field++; } while (0)
# define schedstat_add(rq, field, amt) do { (rq)->field += (amt); } while (0)
# define schedstat_set(var, val) do { var = (val); } while (0)
@@ -126,6 +133,9 @@ 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_inc(rq, field) do { } while (0)
@@ -134,6 +144,11 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta)
#endif
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
static inline void sched_info_reset_dequeued(struct task_struct *t)
{
t->sched_info.last_queued = 0;
}
/*
* Called when a process is dequeued from the active array and given
* the cpu. We should note that with the exception of interactive
@@ -143,15 +158,22 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta)
* active queue, thus delaying tasks in the expired queue from running;
* see scheduler_tick()).
*
* This function is only called from sched_info_arrive(), rather than
* dequeue_task(). Even though a task may be queued and dequeued multiple
* times as it is shuffled about, we're really interested in knowing how
* long it was from the *first* time it was queued to the time that it
* finally hit a cpu.
* Though 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.
*/
static inline void sched_info_dequeued(struct task_struct *t)
{
t->sched_info.last_queued = 0;
unsigned long long now = task_rq(t)->clock, delta = 0;
if (unlikely(sched_info_on()))
if (t->sched_info.last_queued)
delta = now - t->sched_info.last_queued;
sched_info_reset_dequeued(t);
t->sched_info.run_delay += delta;
rq_sched_info_dequeued(task_rq(t), delta);
}
/*
@@ -165,7 +187,7 @@ static void sched_info_arrive(struct task_struct *t)
if (t->sched_info.last_queued)
delta = now - t->sched_info.last_queued;
sched_info_dequeued(t);
sched_info_reset_dequeued(t);
t->sched_info.run_delay += delta;
t->sched_info.last_arrival = now;
t->sched_info.pcount++;
@@ -242,7 +264,9 @@ sched_info_switch(struct task_struct *prev, struct task_struct *next)
__sched_info_switch(prev, next);
}
#else
#define sched_info_queued(t) do { } while (0)
#define sched_info_switch(t, next) do { } while (0)
#define sched_info_queued(t) do { } while (0)
#define sched_info_reset_dequeued(t) do { } while (0)
#define sched_info_dequeued(t) do { } while (0)
#define sched_info_switch(t, next) do { } while (0)
#endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */
kernel/sysctl.c
+8
View File
@@ -264,6 +264,14 @@ static struct ctl_table kern_table[] = {
.extra1 = &min_wakeup_granularity_ns,
.extra2 = &max_wakeup_granularity_ns,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_shares_ratelimit",
.data = &sysctl_sched_shares_ratelimit,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_child_runs_first",
kernel/time/tick-sched.c
+2
View File
@@ -276,6 +276,7 @@ void tick_nohz_stop_sched_tick(void)
ts->tick_stopped = 1;
ts->idle_jiffies = last_jiffies;
rcu_enter_nohz();
sched_clock_tick_stop(cpu);
}
/*
@@ -375,6 +376,7 @@ void tick_nohz_restart_sched_tick(void)
select_nohz_load_balancer(0);
now = ktime_get();
tick_do_update_jiffies64(now);
sched_clock_tick_start(cpu);
cpu_clear(cpu, nohz_cpu_mask);
/*