From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932455AbbI2PK7 (ORCPT ); Tue, 29 Sep 2015 11:10:59 -0400 Received: from smtprelay0108.hostedemail.com ([216.40.44.108]:35828 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756015AbbI2PKu (ORCPT ); Tue, 29 Sep 2015 11:10:50 -0400 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::::::::,RULES_HIT:41:355:379:541:599:800:960:973:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1538:1593:1594:1711:1714:1730:1747:1777:1792:2393:2553:2559:2562:3138:3139:3140:3141:3142:3350:3622:3865:3866:3867:3868:3870:3871:3872:3874:5007:6261:7875:8660:9707:10004:10400:10848:10967:11232:11658:11914:12296:12517:12519:12740:13069:13148:13230:13311:13357:21080,0,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: cup03_413b45ccea620 X-Filterd-Recvd-Size: 1532 Date: Tue, 29 Sep 2015 11:10:47 -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 04/11] sched: Rework TASK_DEAD preemption exception Message-ID: <20150929111047.618f066f@gandalf.local.home> In-Reply-To: <20150929093520.037072067@infradead.org> References: <20150929092825.540553633@infradead.org> <20150929093520.037072067@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 On Tue, 29 Sep 2015 11:28:29 +0200 Peter Zijlstra wrote: > TASK_DEAD is special in that the final schedule call from do_exit() > must be done with preemption disabled. > > This leads to a violation of our new scheduling invariant which states > that the preempt count should be 2. Move the check for TASK_DEAD out > of the debug check and use it to decrement the preempt count (from 2 > to 1). > > Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Steven Rostedt -- Steve