korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-11 20:48:49 +08:00
Code Issues Packages Projects Releases Wiki Activity

sched/fair: Provide runnable_load_avg back to cfs_rq

Browse Source 
The cfs_rq's load_avg is composed of runnable_load_avg and blocked_load_avg.
Before this series, sometimes the runnable_load_avg is used, and sometimes
the load_avg is used. Completely replacing all uses of runnable_load_avg
with load_avg may be too big a leap, i.e., the blocked_load_avg is concerned
to result in overrated load. Therefore, we get runnable_load_avg back.

The new cfs_rq's runnable_load_avg is improved to be updated with all of the
runnable sched_eneities at the same time, so the one sched_entity updated and
the others stale problem is solved.

Signed-off-by: Yuyang Du <yuyang.du@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arjan@linux.intel.com
Cc: bsegall@google.com
Cc: dietmar.eggemann@arm.com
Cc: fengguang.wu@intel.com
Cc: len.brown@intel.com
Cc: morten.rasmussen@arm.com
Cc: pjt@google.com
Cc: rafael.j.wysocki@intel.com
Cc: umgwanakikbuti@gmail.com
Cc: vincent.guittot@linaro.org
Link: http://lkml.kernel.org/r/1436918682-4971-7-git-send-email-yuyang.du@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Yuyang Du 2015-07-15 08:04:41 +08:00 committed by Ingo Molnar
parent 1269557889
commit 139622343e
3 changed files with 49 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
kernel/sched/debug.c
View File

@ -207,6 +207,8 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
#ifdef CONFIG_SMP
SEQ_printf(m, " .%-30s: %lu\n", "load_avg",
cfs_rq->avg.load_avg);
SEQ_printf(m, " .%-30s: %lu\n", "runnable_load_avg",
cfs_rq->runnable_load_avg);
SEQ_printf(m, " .%-30s: %lu\n", "util_avg",
cfs_rq->avg.util_avg);
SEQ_printf(m, " .%-30s: %ld\n", "removed_load_avg",

55
kernel/sched/fair.c
View File

@ -2542,7 +2542,7 @@ static u32 __compute_runnable_contrib(u64 n)
*/
static __always_inline int
__update_load_avg(u64 now, int cpu, struct sched_avg *sa,
unsigned long weight, int running)
unsigned long weight, int running, struct cfs_rq *cfs_rq)
{
u64 delta, periods;
u32 contrib;
@ -2582,8 +2582,11 @@ __update_load_avg(u64 now, int cpu, struct sched_avg *sa,
* period and accrue it.
*/
delta_w = 1024 - delta_w;
if (weight)
if (weight) {
sa->load_sum += weight * delta_w;
if (cfs_rq)
cfs_rq->runnable_load_sum += weight * delta_w;
}
if (running)
sa->util_sum += delta_w * scale_freq >> SCHED_CAPACITY_SHIFT;
@ -2594,19 +2597,29 @@ __update_load_avg(u64 now, int cpu, struct sched_avg *sa,
delta %= 1024;
sa->load_sum = decay_load(sa->load_sum, periods + 1);
if (cfs_rq) {
cfs_rq->runnable_load_sum =
decay_load(cfs_rq->runnable_load_sum, periods + 1);
}
sa->util_sum = decay_load((u64)(sa->util_sum), periods + 1);
/* Efficiently calculate \sum (1..n_period) 1024*y^i */
contrib = __compute_runnable_contrib(periods);
if (weight)
if (weight) {
sa->load_sum += weight * contrib;
if (cfs_rq)
cfs_rq->runnable_load_sum += weight * contrib;
}
if (running)
sa->util_sum += contrib * scale_freq >> SCHED_CAPACITY_SHIFT;
}
/* Remainder of delta accrued against u_0` */
if (weight)
if (weight) {
sa->load_sum += weight * delta;
if (cfs_rq)
cfs_rq->runnable_load_sum += weight * delta;
}
if (running)
sa->util_sum += delta * scale_freq >> SCHED_CAPACITY_SHIFT;
@ -2614,6 +2627,10 @@ __update_load_avg(u64 now, int cpu, struct sched_avg *sa,
if (decayed) {
sa->load_avg = div_u64(sa->load_sum, LOAD_AVG_MAX);
if (cfs_rq) {
cfs_rq->runnable_load_avg =
div_u64(cfs_rq->runnable_load_sum, LOAD_AVG_MAX);
}
sa->util_avg = (sa->util_sum << SCHED_LOAD_SHIFT) / LOAD_AVG_MAX;
}
@ -2661,7 +2678,7 @@ static inline int update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
}
decayed = __update_load_avg(now, cpu_of(rq_of(cfs_rq)), sa,
scale_load_down(cfs_rq->load.weight), cfs_rq->curr != NULL);
scale_load_down(cfs_rq->load.weight), cfs_rq->curr != NULL, cfs_rq);
#ifndef CONFIG_64BIT
smp_wmb();
@ -2683,7 +2700,7 @@ static inline void update_load_avg(struct sched_entity *se, int update_tg)
* track group sched_entity load average for task_h_load calc in migration
*/
__update_load_avg(now, cpu, &se->avg,
se->on_rq * scale_load_down(se->load.weight), cfs_rq->curr == se);
se->on_rq * scale_load_down(se->load.weight), cfs_rq->curr == se, NULL);
if (update_cfs_rq_load_avg(now, cfs_rq) && update_tg)
update_tg_load_avg(cfs_rq, 0);
@ -2703,11 +2720,15 @@ enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
}
else {
__update_load_avg(now, cpu_of(rq_of(cfs_rq)), sa,
se->on_rq * scale_load_down(se->load.weight), cfs_rq->curr == se);
se->on_rq * scale_load_down(se->load.weight),
cfs_rq->curr == se, NULL);
}
decayed = update_cfs_rq_load_avg(now, cfs_rq);
cfs_rq->runnable_load_avg += sa->load_avg;
cfs_rq->runnable_load_sum += sa->load_sum;
if (migrated) {
cfs_rq->avg.load_avg += sa->load_avg;
cfs_rq->avg.load_sum += sa->load_sum;
@ -2719,6 +2740,18 @@ enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
update_tg_load_avg(cfs_rq, 0);
}
/* Remove the runnable load generated by se from cfs_rq's runnable load average */
static inline void
dequeue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
update_load_avg(se, 1);
cfs_rq->runnable_load_avg =
max_t(long, cfs_rq->runnable_load_avg - se->avg.load_avg, 0);
cfs_rq->runnable_load_sum =
max_t(s64, cfs_rq->runnable_load_sum - se->avg.load_sum, 0);
}
/*
* Task first catches up with cfs_rq, and then subtract
* itself from the cfs_rq (task must be off the queue now).
@ -2740,7 +2773,7 @@ void remove_entity_load_avg(struct sched_entity *se)
last_update_time = cfs_rq->avg.last_update_time;
#endif
__update_load_avg(last_update_time, cpu_of(rq_of(cfs_rq)), &se->avg, 0, 0);
__update_load_avg(last_update_time, cpu_of(rq_of(cfs_rq)), &se->avg, 0, 0, NULL);
atomic_long_add(se->avg.load_avg, &cfs_rq->removed_load_avg);
atomic_long_add(se->avg.util_avg, &cfs_rq->removed_util_avg);
}
@ -2770,6 +2803,8 @@ static int idle_balance(struct rq *this_rq);
static inline void update_load_avg(struct sched_entity *se, int update_tg) {}
static inline void
enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {}
static inline void
dequeue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {}
static inline void remove_entity_load_avg(struct sched_entity *se) {}
static inline int idle_balance(struct rq *rq)
@ -2977,7 +3012,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
* Update run-time statistics of the 'current'.
*/
update_curr(cfs_rq);
update_load_avg(se, 1);
dequeue_entity_load_avg(cfs_rq, se);
update_stats_dequeue(cfs_rq, se);
if (flags & DEQUEUE_SLEEP) {
@ -7863,7 +7898,7 @@ static void switched_from_fair(struct rq *rq, struct task_struct *p)
#ifdef CONFIG_SMP
/* Catch up with the cfs_rq and remove our load when we leave */
__update_load_avg(cfs_rq->avg.last_update_time, cpu_of(rq), &se->avg,
se->on_rq * scale_load_down(se->load.weight), cfs_rq->curr == se);
se->on_rq * scale_load_down(se->load.weight), cfs_rq->curr == se, NULL);
cfs_rq->avg.load_avg =
max_t(long, cfs_rq->avg.load_avg - se->avg.load_avg, 0);

2
kernel/sched/sched.h
View File

@ -368,6 +368,8 @@ struct cfs_rq {
* CFS load tracking
*/
struct sched_avg avg;
u64 runnable_load_sum;
unsigned long runnable_load_avg;
#ifdef CONFIG_FAIR_GROUP_SCHED
unsigned long tg_load_avg_contrib;
#endif