The following commit has been merged into the sched/core branch of tip: Commit-ID: 5443a0be6121d557e12951537e10159e4c61035d Gitweb: https://git.kernel.org/tip/5443a0be6121d557e12951537e10159e4c61035d Author: Frederic Weisbecker <frederic@xxxxxxxxxx> AuthorDate: Tue, 03 Dec 2019 17:01:06 +01:00 Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CommitterDate: Tue, 17 Dec 2019 13:32:50 +01:00 sched: Use fair:prio_changed() instead of ad-hoc implementation 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@xxxxxxxxxxxxx> Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Link: https://lkml.kernel.org/r/20191203160106.18806-3-frederic@xxxxxxxxxx --- kernel/sched/core.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 90e4b00..15508c2 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4540,17 +4540,17 @@ void set_user_nice(struct task_struct *p, long nice) p->prio = effective_prio(p); delta = p->prio - old_prio; - if (queued) { + if (queued) enqueue_task(rq, p, ENQUEUE_RESTORE | ENQUEUE_NOCLOCK); - /* - * If the task increased its priority or is running and - * lowered its priority, then reschedule its CPU: - */ - if (delta < 0 || (delta > 0 && task_running(rq, p))) - resched_curr(rq); - } if (running) set_next_task(rq, p); + + /* + * If the task increased its priority or is running and + * lowered its priority, then reschedule its CPU: + */ + p->sched_class->prio_changed(rq, p, old_prio); + out_unlock: task_rq_unlock(rq, p, &rf); }
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