Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751256AbaKFCH2 (ORCPT ); Wed, 5 Nov 2014 21:07:28 -0500 Received: from mga02.intel.com ([134.134.136.20]:45359 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750883AbaKFCH0 (ORCPT ); Wed, 5 Nov 2014 21:07:26 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,691,1406617200"; d="scan'208";a="484928043" Date: Thu, 6 Nov 2014 09:46:34 +0800 From: Wanpeng Li To: Peter Zijlstra Cc: Wanpeng Li , Wanpeng Li , Ingo Molnar , Juri Lelli , Kirill Tkhai , linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH v2] sched/deadline: support dl task migration during cpu hotplug Message-ID: <20141106014634.GA25640@kernel> Reply-To: Wanpeng Li References: <1415177517-7189-1-git-send-email-wanpeng.li@linux.intel.com> <20141105105058.GQ3337@twins.programming.kicks-ass.net> <545A0317.4090406@gmail.com> <20141105125254.GT3337@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20141105125254.GT3337@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Peter, On Wed, Nov 05, 2014 at 01:52:54PM +0100, Peter Zijlstra wrote: >On Wed, Nov 05, 2014 at 06:59:35PM +0800, Wanpeng Li wrote: >> Hi Peter, >> On 14/11/5 下午6:50, Peter Zijlstra wrote: >> >On Wed, Nov 05, 2014 at 04:51:57PM +0800, Wanpeng Li wrote: >> >>Note: dl task can be migrated successfully if rq is offline currently, however, >> >>I'm still not sure why task_rq(task)->rd->span just include the cpu which the dl >> >>task previous running on, so cpu_active_mask is used in the patch. >> >> >> >>Peterz, Juri? >> >So the root domain span is for exclusive cpusets >> >(Documentation/cgroups/cpusets.txt) where we fully separate sets of CPUs >> >and have no load-balancing between the sets. >> > >> >For 'normal' setups the rd->span is the entire machine, but using >> >cpusets you can create more (smaller) domains. >> >> I don't setup any cpusets related stuff, however, task_rq(task)->rd->span >> just include the cpu which the dl task previous running on instead of the >> entire machine in find_later_rq(). > >Ah, it could be that for offline cpus we have a singleton rd. Lemme try I still cannot find where build the singleton rd in the codes, could you point out? Regards, Wanpeng Li >and remember wth we did there. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/