Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754538Ab0BAGlK (ORCPT ); Mon, 1 Feb 2010 01:41:10 -0500 Received: from mail-pz0-f171.google.com ([209.85.222.171]:38406 "EHLO mail-pz0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754186Ab0BAGlI convert rfc822-to-8bit (ORCPT ); Mon, 1 Feb 2010 01:41:08 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=B262BVMakNBznjxBNPRKbBY78aAZ7OnX/Hh87t0rWwF0/XW00CFnR10kaIOqMSLZLf ycIcS9wo8L2bvZBq38sbybbU9adHeIAWfpbSmq7Ao33wpWG2yAVU2Uo/nAlb1XiND+Ty 0emsmElnvH55mmegSClbSTdtRdTTkOsoGw+Fc= MIME-Version: 1.0 In-Reply-To: <4B666F41.9080302@windriver.com> References: <1264631124-4837-1-git-send-email-jason.wessel@windriver.com> <1264631124-4837-2-git-send-email-jason.wessel@windriver.com> <20100129080706.GJ14636@elte.hu> <4B62F5F6.3040401@windriver.com> <4B666F41.9080302@windriver.com> Date: Mon, 1 Feb 2010 14:41:01 +0800 Message-ID: Subject: Re: [PATCH 1/3] softlockup: add sched_clock_tick() to avoid kernel warning on kgdb resume From: Dongdong Deng To: Jason Wessel Cc: Ingo Molnar , Thomas Gleixner , linux-kernel@vger.kernel.org, kgdb-bugreport@lists.sourceforge.net, "Deng, Dongdong" , peterz@infradead.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1397 Lines: 41 On Mon, Feb 1, 2010 at 2:05 PM, Jason Wessel wrote: > Dongdong Deng wrote: >> On Fri, Jan 29, 2010 at 10:51 PM, Jason Wessel >> wrote: >> >>> echo 3 > /proc/sys/kernel/softlockup_thresh >>> >>> And then some kernel code in a thread like: >>>        local_irq_disable(); >>>        printk("Disable local irq for 11 seconds\n"); >>>        mdelay(11000); >>>        local_irq_enable(); >>> >> >> Hi Jason, >> >> Maybe this problem was fixed by >> commit baf48f6577e581a9adb8fe849dc80e24b21d171d - "softlock: fix false >> panic which can occur if softlockup_thresh is reduced". >> > > > That is not the same problem.   The fix you referenced is a corner case > where you end up with the stack trace at the point in time you reduce > the threshold.  The only reason I reduce the threshold in the first > place is just to shorten the amount of time it takes to observe the problem. Thanks for your nice explanation. :) Dongdong > You can just change the numbers for the mdelay and use the default > softlockup threshold values and still see the problem I reported. > > Jason. > -- 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/