From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756620AbbI2Onz (ORCPT ); Tue, 29 Sep 2015 10:43:55 -0400 Received: from smtprelay0034.hostedemail.com ([216.40.44.34]:48588 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754040AbbI2Onf (ORCPT ); Tue, 29 Sep 2015 10:43:35 -0400 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::::::::,RULES_HIT:41:355:379:541:599:800:960:973:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2393:2553:2559:2562:3138:3139:3140:3141:3142:3353:3865:3866:3867:3868:3871:3872:3874:4250:5007:6248:6261:7875:7903:8784:9040:10004:10400:10848:10967:11026:11232:11473:11658:11914:12043:12296:12438:12517:12519:12740:13069:13311:13357:14096:14097:21080,0,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: bean52_76616a8f33e03 X-Filterd-Recvd-Size: 2663 Date: Tue, 29 Sep 2015 10:43:32 -0400 From: Steven Rostedt To: Peter Zijlstra 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: [RFC][PATCH 01/11] sched: Simplify INIT_PREEMPT_COUNT Message-ID: <20150929104332.69571e98@gandalf.local.home> In-Reply-To: <20150929093519.706413197@infradead.org> References: <20150929092825.540553633@infradead.org> <20150929093519.706413197@infradead.org> 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 [ Resend with a "Reply-all" this time! ] On Tue, 29 Sep 2015 11:28:26 +0200 Peter Zijlstra wrote: > As per commit d86ee4809d03 ("sched: optimize cond_resched()") we need > PREEMPT_ACTIVE to avoid cond_resched() from working before the > scheduler is setup. > > However, keeping preemption disabled should do the same thing already, > making the PREEMPT_ACTIVE part entirely redundant. Thus PREEMPT_ACTIVE wasn't needed at that commit either, or was it? > > Signed-off-by: Peter Zijlstra (Intel) > --- > include/linux/sched.h | 7 ++----- > 1 file changed, 2 insertions(+), 5 deletions(-) > > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -608,17 +608,14 @@ struct task_cputime_atomic { > /* > * Disable preemption until the scheduler is running. > * Reset by start_kernel()->sched_init()->init_idle(). > - * > - * We include PREEMPT_ACTIVE to avoid cond_resched() from working > - * before the scheduler is active -- see should_resched(). > */ > -#define INIT_PREEMPT_COUNT (PREEMPT_DISABLED + PREEMPT_ACTIVE) > +#define INIT_PREEMPT_COUNT PREEMPT_DISABLED I can't find anything wrong with this. Reviewed-by: Steven Rostedt -- Steve > > /** > * struct thread_group_cputimer - thread group interval timer counts > * @cputime_atomic: atomic thread group interval timers. > * @running: non-zero when there are timers running and > - * @cputime receives updates. > + * @cputime receives updates. > * > * This structure contains the version of task_cputime, above, that is > * used for thread group CPU timer calculations. >