From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755297Ab3CSKOl (ORCPT ); Tue, 19 Mar 2013 06:14:41 -0400 Received: from merlin.infradead.org ([205.233.59.134]:41039 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755144Ab3CSKOi (ORCPT ); Tue, 19 Mar 2013 06:14:38 -0400 Message-ID: <1363688074.22553.14.camel@laptop> Subject: Re: [PATCH] scheduler: convert BUG_ON()s in try_to_wake_up_local() to WARN_ON_ONCE()s From: Peter Zijlstra To: Tejun Heo Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Steven Rostedt Date: Tue, 19 Mar 2013 11:14:34 +0100 In-Reply-To: <20130318192234.GD3042@htj.dyndns.org> References: <20130318192234.GD3042@htj.dyndns.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.2-0ubuntu0.1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2013-03-18 at 12:22 -0700, Tejun Heo wrote: > 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. Doesn't really matter either way, the printk()s triggered by either will very likely kill the system anyhow ;-)