From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932544AbbI3LPX (ORCPT ); Wed, 30 Sep 2015 07:15:23 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:47278 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932108AbbI3LPT (ORCPT ); Wed, 30 Sep 2015 07:15:19 -0400 Date: Wed, 30 Sep 2015 13:15:12 +0200 From: Peter Zijlstra To: Steven Rostedt Cc: mingo@kernel.org, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, fweisbec@gmail.com, oleg@redhat.com, umgwanakikbuti@gmail.com, tglx@linutronix.de Subject: Re: [PATCH v2 12/12] sched: Add preempt_count invariant check Message-ID: <20150930111512.GC2903@worktop.programming.kicks-ass.net> References: <20150930071035.514587432@infradead.org> <20150930072304.760800554@infradead.org> <20150930053810.52507d1b@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150930053810.52507d1b@gandalf.local.home> User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 30, 2015 at 05:38:10AM -0400, Steven Rostedt wrote: > On Wed, 30 Sep 2015 09:10:47 +0200 > Peter Zijlstra wrote: > > > Ingo requested I keep my debug check for the preempt_count invariant. > > > > Requested-by: Ingo Molnar > > Signed-off-by: Peter Zijlstra (Intel) > > --- > > kernel/sched/core.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > --- a/kernel/sched/core.c > > +++ b/kernel/sched/core.c > > @@ -2514,6 +2514,10 @@ static struct rq *finish_task_switch(str > > * > > * Also, see FORK_PREEMPT_COUNT. > > */ > > + if (unlikely(WARN_ONCE(preempt_count() != 2*PREEMPT_DISABLE_OFFSET, > > Nuke the "unlikely" it's redundant with the WARN_ONCE(). Ah, indeed. *poof*