Commit 383efcd0 authored Mar 18, 2013 by Tejun Heo Committed by Ingo Molnar Mar 21, 2013

sched: Convert BUG_ON()s in try_to_wake_up_local() to WARN_ON_ONCE()s



try_to_wake_up_local() should only be invoked to wake up another
task in the same runqueue and BUG_ON()s are used to enforce the
rule. Missing try_to_wake_up_local() can stall workqueue
execution but such stalls are likely to be finite either by
another work item being queued or the one blocked getting
unblocked.  There's no reason to trigger BUG while holding rq
lock crashing the whole system.

Convert BUG_ON()s in try_to_wake_up_local() to WARN_ON_ONCE()s.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20130318192234.GD3042@htj.dyndns.org


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

parent 7f6575f1

kernel/sched/core.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -1488,8 +1488,10 @@ static void try_to_wake_up_local(struct task_struct *p)
		{
		struct rq *rq = task_rq(p);

		BUG_ON(rq != this_rq());
		BUG_ON(p == current);
		if (WARN_ON_ONCE(rq != this_rq()) \|\|
		WARN_ON_ONCE(p == current))
		return;

		lockdep_assert_held(&rq->lock);

		if (!raw_spin_trylock(&p->pi_lock)) {

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