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sched/core: Fix set_user_nice() 

Almost all scheduler functions update state with the following
pattern:

	if (queued)
		dequeue_task(rq, p, DEQUEUE_SAVE);
	if (running)
		put_prev_task(rq, p);

	/* update state */

	if (queued)
		enqueue_task(rq, p, ENQUEUE_RESTORE);
	if (running)
		set_curr_task(rq, p);

set_user_nice() however misses the running part, cure this.

This was found by asserting we never enqueue 'current'.

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: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
hifive-unleashed-5.1
Peter Zijlstra 2016-09-20 22:06:01 +02:00 committed by Ingo Molnar
parent b2bf6c314e
commit 49bd21efe7
1 changed files with 7 additions and 1 deletions
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8
kernel/sched/core.c
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@ -3724,7 +3724,8 @@ out_unlock:
void set_user_nice(struct task_struct *p, long nice)
{
int old_prio, delta, queued;
bool queued, running;
int old_prio, delta;
struct rq_flags rf;
struct rq *rq;
@ -3746,8 +3747,11 @@ void set_user_nice(struct task_struct *p, long nice)
goto out_unlock;
}
queued = task_on_rq_queued(p);
running = task_current(rq, p);
if (queued)
dequeue_task(rq, p, DEQUEUE_SAVE);
if (running)
put_prev_task(rq, p);
p->static_prio = NICE_TO_PRIO(nice);
set_load_weight(p);
@ -3764,6 +3768,8 @@ void set_user_nice(struct task_struct *p, long nice)
if (delta < 0 || (delta > 0 && task_running(rq, p)))
resched_curr(rq);
}
if (running)
set_curr_task(rq, p);
out_unlock:
task_rq_unlock(rq, p, &rf);
}