From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753807Ab3EGOZD (ORCPT ); Tue, 7 May 2013 10:25:03 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:42074 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932295Ab3EGNke (ORCPT ); Tue, 7 May 2013 09:40:34 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Tejun Heo , Peter Zijlstra , Ingo Molnar , Luis Henriques Subject: [PATCH 011/118] sched: Convert BUG_ON()s in try_to_wake_up_local() to WARN_ON_ONCE()s Date: Tue, 7 May 2013 14:37:37 +0100 Message-Id: <1367933964-1564-12-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1367933964-1564-1-git-send-email-luis.henriques@canonical.com> References: <1367933964-1564-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.5.7.12 -stable 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 Signed-off-by: Luis Henriques --- kernel/sched/core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 3231df8..473cac3 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1651,8 +1651,10 @@ 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)) { -- 1.8.1.2