Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757172AbaKTJKI (ORCPT ); Thu, 20 Nov 2014 04:10:08 -0500 Received: from mga02.intel.com ([134.134.136.20]:12061 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751932AbaKTJKA (ORCPT ); Thu, 20 Nov 2014 04:10:00 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,422,1413270000"; d="scan'208";a="640288240" Date: Thu, 20 Nov 2014 16:49:32 +0800 From: Wanpeng Li To: Peter Zijlstra , Juri Lelli Cc: Kirill Tkhai , Ingo Molnar , linux-kernel@vger.kernel.org, Wanpeng Li Subject: Re: [PATCH v5] sched/deadline: support dl task migration during cpu hotplug Message-ID: <20141120084932.GA3818@kernel> Reply-To: Wanpeng Li References: <1415754413-13988-1-git-send-email-wanpeng.li@linux.intel.com> <1415809626.15631.35.camel@tkhai> <20141112225636.GA23249@kernel> <1415873444.15631.42.camel@tkhai> <546485A2.7050501@gmail.com> <1415874091.15631.44.camel@tkhai> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1415874091.15631.44.camel@tkhai> 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 Peterz, Juri, On Thu, Nov 13, 2014 at 01:21:31PM +0300, Kirill Tkhai wrote: >> > Also, we should think about the following situation. >> > >> > DL task is left on dead rq. In your scheme it will be moved by the timer. >> > But what will be if somebody changes the class of the task (before timer)? >> >> I think timer will be cancelled in switched_from_dl(). > >Yeah, but nobody will move this task to alive rq. > >> > In this case the task still remains on dead rq. >> > >> > We should handle this situation in some way. I think pang's patch handle the exclusive cpusets rd->span issue, the concern which Kirill mentioned above maybe the last one block the patch merged, is there any idea or proposal from you experts? Regards, Wanpeng Li >> > >> > Kirill >> > >> > >> > -- >> > 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/ >> > -- 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/