Commit 15ff991e authored Oct 05, 2016 by Peter Zijlstra Committed by Ingo Molnar Mar 16, 2017

sched/core: Avoid double update_rq_clock() in move_queued_task()



Address this case:

  WARNING: CPU: 0 PID: 2070 at ../kernel/sched/core.c:109 update_rq_clock+0x74/0x80
  rq->clock_update_flags & RQCF_UPDATED

  Call Trace:
  update_rq_clock()
  move_queued_task()
  __set_cpus_allowed_ptr()
  ...

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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 5704ac0a

kernel/sched/core.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -948,7 +948,7 @@ static struct rq move_queued_task(struct rq rq, struct rq_flags *rf,
		lockdep_assert_held(&rq->lock);

		p->on_rq = TASK_ON_RQ_MIGRATING;
		dequeue_task(rq, p, 0);
		dequeue_task(rq, p, DEQUEUE_NOCLOCK);
		set_task_cpu(p, new_cpu);
		rq_unlock(rq, rf);

		@@ -987,6 +987,7 @@ static struct rq __migrate_task(struct rq rq, struct rq_flags *rf,
		if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed))
		return rq;

		update_rq_clock(rq);
		rq = move_queued_task(rq, rf, p, dest_cpu);

		return rq;