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sched: Use fair:prio_changed() instead of ad-hoc implementation

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set_user_nice() implements its own version of fair::prio_changed() and
therefore misses a specific optimization towards nohz_full CPUs that
avoid sending an resched IPI to a reniced task running alone. Use the
proper callback instead.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20191203160106.18806-3-frederic@kernel.org
This commit is contained in:
Frederic Weisbecker 2019-12-03 17:01:06 +01:00 • committed by Peter Zijlstra
parent 7c2e8bbd87
commit 5443a0be61
1 changed files with 8 additions and 8 deletions
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12
kernel/sched/core.c
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@ -4540,17 +4540,17 @@ void set_user_nice(struct task_struct *p, long nice)
p->prio = effective_prio(p); p->prio = effective_prio(p);
delta = p->prio - old_prio; delta = p->prio - old_prio;
if (queued) { if (queued)
enqueue_task(rq, p, ENQUEUE_RESTORE | ENQUEUE_NOCLOCK); enqueue_task(rq, p, ENQUEUE_RESTORE | ENQUEUE_NOCLOCK);
if (running)
set_next_task(rq, p);
/* /*
* If the task increased its priority or is running and * If the task increased its priority or is running and
* lowered its priority, then reschedule its CPU: * lowered its priority, then reschedule its CPU:
*/ */
if (delta < 0 || (delta > 0 && task_running(rq, p))) p->sched_class->prio_changed(rq, p, old_prio);
resched_curr(rq);
}
if (running)
set_next_task(rq, p);
out_unlock: out_unlock:
task_rq_unlock(rq, p, &rf); task_rq_unlock(rq, p, &rf);
} }