From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934594AbbDWNLB (ORCPT ); Thu, 23 Apr 2015 09:11:01 -0400 Received: from smtprelay0002.hostedemail.com ([216.40.44.2]:54854 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932206AbbDWNLA (ORCPT ); Thu, 23 Apr 2015 09:11:00 -0400 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::,RULES_HIT:41:355:379:541:599:800:973:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1539:1593:1594:1711:1730:1747:1777:1792:2393:2553:2559:2562:3138:3139:3140:3141:3142:3150:3352:3622:3865:3866:3867:3868:3871:3872:4250:5007:6119:6120:6261:7875:7901:7903:10004:10400:10848:10967:11232:11658:11914:12517:12519:12740:13069:13255:13311:13357:21080,0,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: art97_5fe5b510e8d4e X-Filterd-Recvd-Size: 1996 Date: Thu, 23 Apr 2015 09:10:57 -0400 From: Steven Rostedt To: pang.xunlei@zte.com.cn Cc: Juri Lelli , linux-kernel@vger.kernel.org, Xunlei Pang , Peter Zijlstra Subject: Re: [PATCH v6 2/3] sched/rt: Fix wrong SMP scheduler behavior for equal prio cases Message-ID: <20150423091057.05bcc309@gandalf.local.home> In-Reply-To: References: <1429518168-7965-1-git-send-email-xlpang@126.com> <1429518168-7965-2-git-send-email-xlpang@126.com> <20150420105228.461e103c@gandalf.local.home> <20150420172048.GZ27490@worktop.programming.kicks-ass.net> <20150420134803.5446e32d@gandalf.local.home> <20150422230122.3637f11f@grimm.local.home> X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.25; 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 Thu, 23 Apr 2015 14:53:27 +0800 pang.xunlei@zte.com.cn wrote: > > Why not use Peter's idea of instead of checking PREEMPT_ACTIVE, just > > check if the task is on the runqueue or not. If it scheduled out, it > > would take itself off the runqueue, if it was preempted by anything, it > > would still be on the run queue, and according to FIFO, it should still > > maintain CPU ownership over other tasks of the same prio. > > > > But for yield() or RR scheduling when running out of time slice, > I think this would be still inappropriate, am I missing something? Good point, I'll have to look into this a bit more. -- Steve