From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755721AbbI2Ok6 (ORCPT ); Tue, 29 Sep 2015 10:40:58 -0400 Received: from smtprelay0094.hostedemail.com ([216.40.44.94]:36879 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754076AbbI2Okr (ORCPT ); Tue, 29 Sep 2015 10:40:47 -0400 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::::::::,RULES_HIT:41:355:379:541:599:800:960:973:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1539:1593:1594:1711:1730:1747:1777:1792:2393:2553:2559:2562:3138:3139:3140:3141:3142:3352:3622:3870:3872:3874:3876:5007:6119:6261:7875:7903:10004:10400:10848:10967:11026:11232:11658:11914:12043:12219:12438:12517:12519:12740:13069:13311:13357:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: flag19_5de37b0e8311c X-Filterd-Recvd-Size: 1816 Date: Tue, 29 Sep 2015 10:40:44 -0400 From: Steven Rostedt To: Peter Zijlstra Cc: Frederic Weisbecker , mingo@kernel.org, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, oleg@redhat.com, umgwanakikbuti@gmail.com, tglx@linutronix.de Subject: Re: [RFC][PATCH 02/11] sched: Create preempt_count invariant Message-ID: <20150929104044.60172e41@gandalf.local.home> In-Reply-To: <20150929130201.GH3816@twins.programming.kicks-ass.net> References: <20150929092825.540553633@infradead.org> <20150929093519.817299442@infradead.org> <20150929125512.GB31582@lerouge> <20150929130201.GH3816@twins.programming.kicks-ass.net> X-Mailer: Claws Mail 3.12.0 (GTK+ 2.24.28; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 29 Sep 2015 15:02:01 +0200 Peter Zijlstra wrote: > On Tue, Sep 29, 2015 at 02:55:13PM +0200, Frederic Weisbecker wrote: > > On Tue, Sep 29, 2015 at 11:28:27AM +0200, Peter Zijlstra wrote: > > > #define init_task_preempt_count(p) do { \ > > > - task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \ > > > + task_thread_info(p)->preempt_count = 2*PREEMPT_DISABLED; \ > > > > Since it's not quite obvious why we use this magic value without looking > > at schedule_tail() details, maybe add a little comment? (Just "/* see schedule_tail() */"). > > Right, I fixed that in 12/11 v2. I'll change that around a bit. I'll wait for v2 because this confused me too. -- Steve