Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752515Ab3ETGXw (ORCPT ); Mon, 20 May 2013 02:23:52 -0400 Received: from e28smtp09.in.ibm.com ([122.248.162.9]:36083 "EHLO e28smtp09.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751077Ab3ETGXv (ORCPT ); Mon, 20 May 2013 02:23:51 -0400 Message-ID: <5199C169.7060504@linux.vnet.ibm.com> Date: Mon, 20 May 2013 14:23:37 +0800 From: Michael Wang User-Agent: Mozilla/5.0 (X11; Linux i686; rv:16.0) Gecko/20121011 Thunderbird/16.0.1 MIME-Version: 1.0 To: Borislav Petkov CC: "Paul E. McKenney" , Jiri Kosina , Frederic Weisbecker , Tony Luck , linux-kernel@vger.kernel.org, x86@kernel.org, Thomas Gleixner Subject: Re: NOHZ: WARNING: at arch/x86/kernel/smp.c:123 native_smp_send_reschedule, round 2 References: <20130509125040.GF27333@pd.tnic> <20130509125859.GG27333@pd.tnic> <20130515184528.GO4442@linux.vnet.ibm.com> <20130515224358.GF11783@pd.tnic> <20130515235512.GT4442@linux.vnet.ibm.com> <20130517135641.GF23035@pd.tnic> <51999591.8030401@linux.vnet.ibm.com> <20130520045023.GA12690@pd.tnic> In-Reply-To: <20130520045023.GA12690@pd.tnic> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13052006-2674-0000-0000-00000908A762 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1090 Lines: 32 On 05/20/2013 12:50 PM, Borislav Petkov wrote: > On Mon, May 20, 2013 at 11:16:33AM +0800, Michael Wang wrote: >> I suppose the reason is that the cpu we passed to >> mod_delayed_work_on() has a chance to become offline before we >> disabled irq, what about check it before send resched ipi? like: > > I think this is only addressing the symptoms - what we should be doing > instead is asking ourselves why are we even scheduling work on a cpu if > the machine goes offline? > > I don't know though who should be responsible for killing all that > work - the workqueue itself or the guy who created it, i.e. cpufreq > governor... So there are two questions here: 1. Is gov_queue_work() want to queue the work on offline cpu? 2. Is mod_delayed_work_on() allow offline cpu? I guess both should be false? Regards, Michael Wang > > Hmmm. > -- 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/