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schedstat: consolidate per-task cpu runtime stats 

Impact: simplify code

When we turn on CONFIG_SCHEDSTATS, per-task cpu runtime is accumulated
twice. Once in task->se.sum_exec_runtime and once in sched_info.cpu_time.
These two stats are exactly the same.

Given that task->se.sum_exec_runtime is always accumulated by the core
scheduler, sched_info can reuse that data instead of duplicate the accounting.

Signed-off-by: Ken Chen <kenchen@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Ken Chen 2008-12-16 23:41:22 -08:00 committed by Ingo Molnar
parent e9515c3c9f
commit 9c2c48020e
5 changed files with 7 additions and 7 deletions
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2
fs/proc/base.c
View File

@ -347,7 +347,7 @@ static int proc_pid_wchan(struct task_struct *task, char *buffer)
static int proc_pid_schedstat(struct task_struct *task, char *buffer)
{
return sprintf(buffer, "%llu %llu %lu\n",
task->sched_info.cpu_time,
task->se.sum_exec_runtime,
task->sched_info.run_delay,
task->sched_info.pcount);
}

3
include/linux/sched.h
View File

@ -670,8 +670,7 @@ struct reclaim_state;
struct sched_info {
/* cumulative counters */
unsigned long pcount; /* # of times run on this cpu */
unsigned long long cpu_time, /* time spent on the cpu */
run_delay; /* time spent waiting on a runqueue */
unsigned long long run_delay; /* time spent waiting on a runqueue */
/* timestamps */
unsigned long long last_arrival,/* when we last ran on a cpu */

2
kernel/delayacct.c
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@ -127,7 +127,7 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk)
*/
t1 = tsk->sched_info.pcount;
t2 = tsk->sched_info.run_delay;
t3 = tsk->sched_info.cpu_time;
t3 = tsk->se.sum_exec_runtime;
d->cpu_count += t1;

2
kernel/sched.c
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@ -596,6 +596,8 @@ struct rq {
#ifdef CONFIG_SCHEDSTATS
/* latency stats */
struct sched_info rq_sched_info;
unsigned long long rq_cpu_time;
/* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
/* sys_sched_yield() stats */
unsigned int yld_exp_empty;

5
kernel/sched_stats.h
View File

@ -31,7 +31,7 @@ static int show_schedstat(struct seq_file *seq, void *v)
rq->yld_act_empty, rq->yld_exp_empty, rq->yld_count,
rq->sched_switch, rq->sched_count, rq->sched_goidle,
rq->ttwu_count, rq->ttwu_local,
rq->rq_sched_info.cpu_time,
rq->rq_cpu_time,
rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);
seq_printf(seq, "\n");
@ -123,7 +123,7 @@ static inline void
rq_sched_info_depart(struct rq *rq, unsigned long long delta)
{
if (rq)
rq->rq_sched_info.cpu_time += delta;
rq->rq_cpu_time += delta;
}
static inline void
@ -236,7 +236,6 @@ static inline void sched_info_depart(struct task_struct *t)
unsigned long long delta = task_rq(t)->clock -
t->sched_info.last_arrival;
t->sched_info.cpu_time += delta;
rq_sched_info_depart(task_rq(t), delta);
if (t->state == TASK_RUNNING)