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sched: Fix schedstat.nr_wakeups_migrate

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While looking over the code I found that with the ttwu rework the
nr_wakeups_migrate test broke since we now switch cpus prior to
calling ttwu_stat(), hence the test is always true.

Cure this by passing the migration state in wake_flags. Also move the
whole test under CONFIG_SMP, its hard to migrate tasks on UP :-)

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-pwwxl7gdqs5676f1d4cx6pj7@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2011-05-31 10:49:20 +02:00 committed by Ingo Molnar
parent f01114cb59
commit f339b9dc1f
2 changed files with 8 additions and 4 deletions
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1
include/linux/sched.h
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@ -1063,6 +1063,7 @@ struct sched_domain;
*/ */
#define WF_SYNC 0x01 /* waker goes to sleep after wakup */ #define WF_SYNC 0x01 /* waker goes to sleep after wakup */
#define WF_FORK 0x02 /* child wakeup after fork */ #define WF_FORK 0x02 /* child wakeup after fork */
#define WF_MIGRATED 0x04 /* internal use, task got migrated */
#define ENQUEUE_WAKEUP 1 #define ENQUEUE_WAKEUP 1
#define ENQUEUE_HEAD 2 #define ENQUEUE_HEAD 2

11
kernel/sched.c
View file

@ -2447,6 +2447,10 @@ ttwu_stat(struct task_struct *p, int cpu, int wake_flags)
} }
rcu_read_unlock(); rcu_read_unlock();
} }
if (wake_flags & WF_MIGRATED)
schedstat_inc(p, se.statistics.nr_wakeups_migrate);
#endif /* CONFIG_SMP */ #endif /* CONFIG_SMP */
schedstat_inc(rq, ttwu_count); schedstat_inc(rq, ttwu_count);
@ -2455,9 +2459,6 @@ ttwu_stat(struct task_struct *p, int cpu, int wake_flags)
if (wake_flags & WF_SYNC) if (wake_flags & WF_SYNC)
schedstat_inc(p, se.statistics.nr_wakeups_sync); schedstat_inc(p, se.statistics.nr_wakeups_sync);
if (cpu != task_cpu(p))
schedstat_inc(p, se.statistics.nr_wakeups_migrate);
#endif /* CONFIG_SCHEDSTATS */ #endif /* CONFIG_SCHEDSTATS */
} }
@ -2675,8 +2676,10 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
p->sched_class->task_waking(p); p->sched_class->task_waking(p);
cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags); cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
if (task_cpu(p) != cpu) if (task_cpu(p) != cpu) {
wake_flags |= WF_MIGRATED;
set_task_cpu(p, cpu); set_task_cpu(p, cpu);
}
#endif /* CONFIG_SMP */ #endif /* CONFIG_SMP */
ttwu_queue(p, cpu); ttwu_queue(p, cpu);