From a2fdf1676265df57ca25b9aa7981d458a045f44d Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 18 Mar 2013 12:22:34 -0700 Subject: [PATCH] sched: Convert BUG_ON()s in try_to_wake_up_local() to WARN_ON_ONCE()s commit 383efcd00053ec40023010ce5034bd702e7ab373 upstream. 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 Acked-by: Steven Rostedt Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20130318192234.GD3042@htj.dyndns.org Signed-off-by: Ingo Molnar [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings --- kernel/sched.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index eeeec4e6fa04..d08c9f4b9fce 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2889,8 +2889,10 @@ 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)) { -- 2.39.2