Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755996Ab3DVOtY (ORCPT ); Mon, 22 Apr 2013 10:49:24 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51447 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754457Ab3DVO3h (ORCPT ); Mon, 22 Apr 2013 10:29:37 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Ingo Molnar" , "Peter Zijlstra" , "Steven Rostedt" , "Tejun Heo" Date: Mon, 22 Apr 2013 15:25:59 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [75/75] sched: Convert BUG_ON()s in try_to_wake_up_local() to WARN_ON_ONCE()s In-Reply-To: X-SA-Exim-Connect-IP: 2001:470:1f08:1539:6834:ff73:7553:7f84 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1673 Lines: 50 3.2.44-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Tejun Heo 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(-) --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2889,8 +2889,10 @@ static void try_to_wake_up_local(struct { 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)) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/