Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler changes from Ingo Molnar:
 "Main changes:

   - scheduler side full-dynticks (user-space execution is undisturbed
     and receives no timer IRQs) preparation changes that convert the
     cputime accounting code to be full-dynticks ready, from Frederic
     Weisbecker.

   - Initial sched.h split-up changes, by Clark Williams

   - select_idle_sibling() performance improvement by Mike Galbraith:

        " 1 tbench pair (worst case) in a 10 core + SMT package:

          pre   15.22 MB/sec 1 procs
          post 252.01 MB/sec 1 procs "

  - sched_rr_get_interval() ABI fix/change.  We think this detail is not
    used by apps (so it's not an ABI in practice), but lets keep it
    under observation.

  - misc RT scheduling cleanups, optimizations"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  sched/rt: Add <linux/sched/rt.h> header to <linux/init_task.h>
  cputime: Remove irqsave from seqlock readers
  sched, powerpc: Fix sched.h split-up build failure
  cputime: Restore CPU_ACCOUNTING config defaults for PPC64
  sched/rt: Move rt specific bits into new header file
  sched/rt: Add a tuning knob to allow changing SCHED_RR timeslice
  sched: Move sched.h sysctl bits into separate header
  sched: Fix signedness bug in yield_to()
  sched: Fix select_idle_sibling() bouncing cow syndrome
  sched/rt: Further simplify pick_rt_task()
  sched/rt: Do not account zero delta_exec in update_curr_rt()
  cputime: Safely read cputime of full dynticks CPUs
  kvm: Prepare to add generic guest entry/exit callbacks
  cputime: Use accessors to read task cputime stats
  cputime: Allow dynamic switch between tick/virtual based cputime accounting
  cputime: Generic on-demand virtual cputime accounting
  cputime: Move default nsecs_to_cputime() to jiffies based cputime file
  cputime: Librarize per nsecs resolution cputime definitions
  cputime: Avoid multiplication overflow on utime scaling
  context_tracking: Export context state for generic vtime
  ...

Fix up conflict in kernel/context_tracking.c due to comment additions.
This commit is contained in:
Linus Torvalds
2013-02-19 18:19:48 -08:00
83 changed files with 1106 additions and 508 deletions

View File

@@ -4371,7 +4371,7 @@ bool __sched yield_to(struct task_struct *p, bool preempt)
struct task_struct *curr = current;
struct rq *rq, *p_rq;
unsigned long flags;
bool yielded = 0;
int yielded = 0;
local_irq_save(flags);
rq = this_rq();
@@ -4667,6 +4667,7 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
*/
idle->sched_class = &idle_sched_class;
ftrace_graph_init_idle_task(idle, cpu);
vtime_init_idle(idle);
#if defined(CONFIG_SMP)
sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu);
#endif
@@ -7508,6 +7509,25 @@ static int sched_rt_global_constraints(void)
}
#endif /* CONFIG_RT_GROUP_SCHED */
int sched_rr_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos)
{
int ret;
static DEFINE_MUTEX(mutex);
mutex_lock(&mutex);
ret = proc_dointvec(table, write, buffer, lenp, ppos);
/* make sure that internally we keep jiffies */
/* also, writing zero resets timeslice to default */
if (!ret && write) {
sched_rr_timeslice = sched_rr_timeslice <= 0 ?
RR_TIMESLICE : msecs_to_jiffies(sched_rr_timeslice);
}
mutex_unlock(&mutex);
return ret;
}
int sched_rt_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos)

View File

@@ -28,6 +28,8 @@
*/
#include <linux/gfp.h>
#include <linux/sched.h>
#include <linux/sched/rt.h>
#include "cpupri.h"
/* Convert between a 140 based task->prio, and our 102 based cpupri */

View File

@@ -3,6 +3,7 @@
#include <linux/tsacct_kern.h>
#include <linux/kernel_stat.h>
#include <linux/static_key.h>
#include <linux/context_tracking.h>
#include "sched.h"
@@ -163,7 +164,7 @@ void account_user_time(struct task_struct *p, cputime_t cputime,
task_group_account_field(p, index, (__force u64) cputime);
/* Account for user time used */
acct_update_integrals(p);
acct_account_cputime(p);
}
/*
@@ -213,7 +214,7 @@ void __account_system_time(struct task_struct *p, cputime_t cputime,
task_group_account_field(p, index, (__force u64) cputime);
/* Account for system time used */
acct_update_integrals(p);
acct_account_cputime(p);
}
/*
@@ -295,6 +296,7 @@ static __always_inline bool steal_account_process_tick(void)
void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
{
struct signal_struct *sig = tsk->signal;
cputime_t utime, stime;
struct task_struct *t;
times->utime = sig->utime;
@@ -308,16 +310,15 @@ void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
t = tsk;
do {
times->utime += t->utime;
times->stime += t->stime;
task_cputime(tsk, &utime, &stime);
times->utime += utime;
times->stime += stime;
times->sum_exec_runtime += task_sched_runtime(t);
} while_each_thread(tsk, t);
out:
rcu_read_unlock();
}
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
/*
* Account a tick to a process and cpustat
@@ -382,11 +383,12 @@ static void irqtime_account_idle_ticks(int ticks)
irqtime_account_process_tick(current, 0, rq);
}
#else /* CONFIG_IRQ_TIME_ACCOUNTING */
static void irqtime_account_idle_ticks(int ticks) {}
static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
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) {}
#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
/*
* Account a single tick of cpu time.
* @p: the process that the cpu time gets accounted to
@@ -397,6 +399,9 @@ void account_process_tick(struct task_struct *p, int user_tick)
cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
struct rq *rq = this_rq();
if (vtime_accounting_enabled())
return;
if (sched_clock_irqtime) {
irqtime_account_process_tick(p, user_tick, rq);
return;
@@ -438,8 +443,7 @@ void account_idle_ticks(unsigned long ticks)
account_idle_time(jiffies_to_cputime(ticks));
}
#endif
#endif /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
/*
* Use precise platform statistics if available:
@@ -461,25 +465,20 @@ void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime
*st = cputime.stime;
}
void vtime_account_system_irqsafe(struct task_struct *tsk)
{
unsigned long flags;
local_irq_save(flags);
vtime_account_system(tsk);
local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(vtime_account_system_irqsafe);
#ifndef __ARCH_HAS_VTIME_TASK_SWITCH
void vtime_task_switch(struct task_struct *prev)
{
if (!vtime_accounting_enabled())
return;
if (is_idle_task(prev))
vtime_account_idle(prev);
else
vtime_account_system(prev);
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
vtime_account_user(prev);
#endif
arch_vtime_task_switch(prev);
}
#endif
@@ -493,27 +492,40 @@ void vtime_task_switch(struct task_struct *prev)
* vtime_account().
*/
#ifndef __ARCH_HAS_VTIME_ACCOUNT
void vtime_account(struct task_struct *tsk)
void vtime_account_irq_enter(struct task_struct *tsk)
{
if (in_interrupt() || !is_idle_task(tsk))
vtime_account_system(tsk);
else
vtime_account_idle(tsk);
if (!vtime_accounting_enabled())
return;
if (!in_interrupt()) {
/*
* If we interrupted user, context_tracking_in_user()
* is 1 because the context tracking don't hook
* on irq entry/exit. This way we know if
* we need to flush user time on kernel entry.
*/
if (context_tracking_in_user()) {
vtime_account_user(tsk);
return;
}
if (is_idle_task(tsk)) {
vtime_account_idle(tsk);
return;
}
}
vtime_account_system(tsk);
}
EXPORT_SYMBOL_GPL(vtime_account);
EXPORT_SYMBOL_GPL(vtime_account_irq_enter);
#endif /* __ARCH_HAS_VTIME_ACCOUNT */
#else
#else /* !CONFIG_VIRT_CPU_ACCOUNTING */
#ifndef nsecs_to_cputime
# define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs)
#endif
static cputime_t scale_utime(cputime_t utime, cputime_t rtime, cputime_t total)
static cputime_t scale_stime(cputime_t stime, cputime_t rtime, cputime_t total)
{
u64 temp = (__force u64) rtime;
temp *= (__force u64) utime;
temp *= (__force u64) stime;
if (sizeof(cputime_t) == 4)
temp = div_u64(temp, (__force u32) total);
@@ -531,10 +543,10 @@ static void cputime_adjust(struct task_cputime *curr,
struct cputime *prev,
cputime_t *ut, cputime_t *st)
{
cputime_t rtime, utime, total;
cputime_t rtime, stime, total;
utime = curr->utime;
total = utime + curr->stime;
stime = curr->stime;
total = stime + curr->utime;
/*
* Tick based cputime accounting depend on random scheduling
@@ -549,17 +561,17 @@ static void cputime_adjust(struct task_cputime *curr,
rtime = nsecs_to_cputime(curr->sum_exec_runtime);
if (total)
utime = scale_utime(utime, rtime, total);
stime = scale_stime(stime, rtime, total);
else
utime = rtime;
stime = rtime;
/*
* If the tick based count grows faster than the scheduler one,
* the result of the scaling may go backward.
* Let's enforce monotonicity.
*/
prev->utime = max(prev->utime, utime);
prev->stime = max(prev->stime, rtime - prev->utime);
prev->stime = max(prev->stime, stime);
prev->utime = max(prev->utime, rtime - prev->stime);
*ut = prev->utime;
*st = prev->stime;
@@ -568,11 +580,10 @@ static void cputime_adjust(struct task_cputime *curr,
void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
{
struct task_cputime cputime = {
.utime = p->utime,
.stime = p->stime,
.sum_exec_runtime = p->se.sum_exec_runtime,
};
task_cputime(p, &cputime.utime, &cputime.stime);
cputime_adjust(&cputime, &p->prev_cputime, ut, st);
}
@@ -586,4 +597,221 @@ void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime
thread_group_cputime(p, &cputime);
cputime_adjust(&cputime, &p->signal->prev_cputime, ut, st);
}
#endif
#endif /* !CONFIG_VIRT_CPU_ACCOUNTING */
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
static unsigned long long vtime_delta(struct task_struct *tsk)
{
unsigned long long clock;
clock = sched_clock();
if (clock < tsk->vtime_snap)
return 0;
return clock - tsk->vtime_snap;
}
static cputime_t get_vtime_delta(struct task_struct *tsk)
{
unsigned long long delta = vtime_delta(tsk);
WARN_ON_ONCE(tsk->vtime_snap_whence == VTIME_SLEEPING);
tsk->vtime_snap += delta;
/* CHECKME: always safe to convert nsecs to cputime? */
return nsecs_to_cputime(delta);
}
static void __vtime_account_system(struct task_struct *tsk)
{
cputime_t delta_cpu = get_vtime_delta(tsk);
account_system_time(tsk, irq_count(), delta_cpu, cputime_to_scaled(delta_cpu));
}
void vtime_account_system(struct task_struct *tsk)
{
if (!vtime_accounting_enabled())
return;
write_seqlock(&tsk->vtime_seqlock);
__vtime_account_system(tsk);
write_sequnlock(&tsk->vtime_seqlock);
}
void vtime_account_irq_exit(struct task_struct *tsk)
{
if (!vtime_accounting_enabled())
return;
write_seqlock(&tsk->vtime_seqlock);
if (context_tracking_in_user())
tsk->vtime_snap_whence = VTIME_USER;
__vtime_account_system(tsk);
write_sequnlock(&tsk->vtime_seqlock);
}
void vtime_account_user(struct task_struct *tsk)
{
cputime_t delta_cpu;
if (!vtime_accounting_enabled())
return;
delta_cpu = get_vtime_delta(tsk);
write_seqlock(&tsk->vtime_seqlock);
tsk->vtime_snap_whence = VTIME_SYS;
account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu));
write_sequnlock(&tsk->vtime_seqlock);
}
void vtime_user_enter(struct task_struct *tsk)
{
if (!vtime_accounting_enabled())
return;
write_seqlock(&tsk->vtime_seqlock);
tsk->vtime_snap_whence = VTIME_USER;
__vtime_account_system(tsk);
write_sequnlock(&tsk->vtime_seqlock);
}
void vtime_guest_enter(struct task_struct *tsk)
{
write_seqlock(&tsk->vtime_seqlock);
__vtime_account_system(tsk);
current->flags |= PF_VCPU;
write_sequnlock(&tsk->vtime_seqlock);
}
void vtime_guest_exit(struct task_struct *tsk)
{
write_seqlock(&tsk->vtime_seqlock);
__vtime_account_system(tsk);
current->flags &= ~PF_VCPU;
write_sequnlock(&tsk->vtime_seqlock);
}
void vtime_account_idle(struct task_struct *tsk)
{
cputime_t delta_cpu = get_vtime_delta(tsk);
account_idle_time(delta_cpu);
}
bool vtime_accounting_enabled(void)
{
return context_tracking_active();
}
void arch_vtime_task_switch(struct task_struct *prev)
{
write_seqlock(&prev->vtime_seqlock);
prev->vtime_snap_whence = VTIME_SLEEPING;
write_sequnlock(&prev->vtime_seqlock);
write_seqlock(&current->vtime_seqlock);
current->vtime_snap_whence = VTIME_SYS;
current->vtime_snap = sched_clock();
write_sequnlock(&current->vtime_seqlock);
}
void vtime_init_idle(struct task_struct *t)
{
unsigned long flags;
write_seqlock_irqsave(&t->vtime_seqlock, flags);
t->vtime_snap_whence = VTIME_SYS;
t->vtime_snap = sched_clock();
write_sequnlock_irqrestore(&t->vtime_seqlock, flags);
}
cputime_t task_gtime(struct task_struct *t)
{
unsigned int seq;
cputime_t gtime;
do {
seq = read_seqbegin(&t->vtime_seqlock);
gtime = t->gtime;
if (t->flags & PF_VCPU)
gtime += vtime_delta(t);
} while (read_seqretry(&t->vtime_seqlock, seq));
return gtime;
}
/*
* Fetch cputime raw values from fields of task_struct and
* add up the pending nohz execution time since the last
* cputime snapshot.
*/
static void
fetch_task_cputime(struct task_struct *t,
cputime_t *u_dst, cputime_t *s_dst,
cputime_t *u_src, cputime_t *s_src,
cputime_t *udelta, cputime_t *sdelta)
{
unsigned int seq;
unsigned long long delta;
do {
*udelta = 0;
*sdelta = 0;
seq = read_seqbegin(&t->vtime_seqlock);
if (u_dst)
*u_dst = *u_src;
if (s_dst)
*s_dst = *s_src;
/* Task is sleeping, nothing to add */
if (t->vtime_snap_whence == VTIME_SLEEPING ||
is_idle_task(t))
continue;
delta = vtime_delta(t);
/*
* Task runs either in user or kernel space, add pending nohz time to
* the right place.
*/
if (t->vtime_snap_whence == VTIME_USER || t->flags & PF_VCPU) {
*udelta = delta;
} else {
if (t->vtime_snap_whence == VTIME_SYS)
*sdelta = delta;
}
} while (read_seqretry(&t->vtime_seqlock, seq));
}
void task_cputime(struct task_struct *t, cputime_t *utime, cputime_t *stime)
{
cputime_t udelta, sdelta;
fetch_task_cputime(t, utime, stime, &t->utime,
&t->stime, &udelta, &sdelta);
if (utime)
*utime += udelta;
if (stime)
*stime += sdelta;
}
void task_cputime_scaled(struct task_struct *t,
cputime_t *utimescaled, cputime_t *stimescaled)
{
cputime_t udelta, sdelta;
fetch_task_cputime(t, utimescaled, stimescaled,
&t->utimescaled, &t->stimescaled, &udelta, &sdelta);
if (utimescaled)
*utimescaled += cputime_to_scaled(udelta);
if (stimescaled)
*stimescaled += cputime_to_scaled(sdelta);
}
#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */

View File

@@ -1680,9 +1680,7 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
}
/* ensure we never gain time by being placed backwards. */
vruntime = max_vruntime(se->vruntime, vruntime);
se->vruntime = vruntime;
se->vruntime = max_vruntime(se->vruntime, vruntime);
}
static void check_enqueue_throttle(struct cfs_rq *cfs_rq);
@@ -3254,25 +3252,18 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
*/
static int select_idle_sibling(struct task_struct *p, int target)
{
int cpu = smp_processor_id();
int prev_cpu = task_cpu(p);
struct sched_domain *sd;
struct sched_group *sg;
int i;
int i = task_cpu(p);
if (idle_cpu(target))
return target;
/*
* If the task is going to be woken-up on this cpu and if it is
* already idle, then it is the right target.
* If the prevous cpu is cache affine and idle, don't be stupid.
*/
if (target == cpu && idle_cpu(cpu))
return cpu;
/*
* If the task is going to be woken-up on the cpu where it previously
* ran and if it is currently idle, then it the right target.
*/
if (target == prev_cpu && idle_cpu(prev_cpu))
return prev_cpu;
if (i != target && cpus_share_cache(i, target) && idle_cpu(i))
return i;
/*
* Otherwise, iterate the domains and find an elegible idle cpu.
@@ -3286,7 +3277,7 @@ static int select_idle_sibling(struct task_struct *p, int target)
goto next;
for_each_cpu(i, sched_group_cpus(sg)) {
if (!idle_cpu(i))
if (i == target || !idle_cpu(i))
goto next;
}
@@ -6101,7 +6092,7 @@ static unsigned int get_rr_interval_fair(struct rq *rq, struct task_struct *task
* idle runqueue:
*/
if (rq->cfs.load.weight)
rr_interval = NS_TO_JIFFIES(sched_slice(&rq->cfs, se));
rr_interval = NS_TO_JIFFIES(sched_slice(cfs_rq_of(se), se));
return rr_interval;
}

View File

@@ -7,6 +7,8 @@
#include <linux/slab.h>
int sched_rr_timeslice = RR_TIMESLICE;
static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun);
struct rt_bandwidth def_rt_bandwidth;
@@ -925,8 +927,8 @@ static void update_curr_rt(struct rq *rq)
return;
delta_exec = rq->clock_task - curr->se.exec_start;
if (unlikely((s64)delta_exec < 0))
delta_exec = 0;
if (unlikely((s64)delta_exec <= 0))
return;
schedstat_set(curr->se.statistics.exec_max,
max(curr->se.statistics.exec_max, delta_exec));
@@ -1427,8 +1429,7 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)
{
if (!task_running(rq, p) &&
(cpu < 0 || cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) &&
(p->nr_cpus_allowed > 1))
cpumask_test_cpu(cpu, tsk_cpus_allowed(p)))
return 1;
return 0;
}
@@ -1889,8 +1890,11 @@ static void switched_from_rt(struct rq *rq, struct task_struct *p)
* we may need to handle the pulling of RT tasks
* now.
*/
if (p->on_rq && !rq->rt.rt_nr_running)
pull_rt_task(rq);
if (!p->on_rq || rq->rt.rt_nr_running)
return;
if (pull_rt_task(rq))
resched_task(rq->curr);
}
void init_sched_rt_class(void)
@@ -1985,7 +1989,11 @@ static void watchdog(struct rq *rq, struct task_struct *p)
if (soft != RLIM_INFINITY) {
unsigned long next;
p->rt.timeout++;
if (p->rt.watchdog_stamp != jiffies) {
p->rt.timeout++;
p->rt.watchdog_stamp = jiffies;
}
next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ);
if (p->rt.timeout > next)
p->cputime_expires.sched_exp = p->se.sum_exec_runtime;
@@ -2010,7 +2018,7 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
if (--p->rt.time_slice)
return;
p->rt.time_slice = RR_TIMESLICE;
p->rt.time_slice = sched_rr_timeslice;
/*
* Requeue to the end of queue if we (and all of our ancestors) are the
@@ -2041,7 +2049,7 @@ static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task)
* Time slice is 0 for SCHED_FIFO tasks
*/
if (task->policy == SCHED_RR)
return RR_TIMESLICE;
return sched_rr_timeslice;
else
return 0;
}

View File

@@ -1,5 +1,7 @@
#include <linux/sched.h>
#include <linux/sched/sysctl.h>
#include <linux/sched/rt.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/stop_machine.h>