From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752490Ab2IJRIj (ORCPT ); Mon, 10 Sep 2012 13:08:39 -0400 Received: from e38.co.us.ibm.com ([32.97.110.159]:55308 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751495Ab2IJRIh (ORCPT ); Mon, 10 Sep 2012 13:08:37 -0400 Message-ID: <504E1E19.9050106@linaro.org> Date: Mon, 10 Sep 2012 10:06:33 -0700 From: John Stultz User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120827 Thunderbird/15.0 MIME-Version: 1.0 To: Fengguang Wu CC: Thomas Gleixner , Ingo Molnar , LKML Subject: Re: BUG: soft lockup - CPU#1 stuck for 1024s! References: <20120909075927.GA13058@localhost> In-Reply-To: <20120909075927.GA13058@localhost> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12091017-5518-0000-0000-00000789E142 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/09/2012 12:59 AM, Fengguang Wu wrote: > Hi John, > > The below lockup warning pops up very occasionally in kvm guest > kernels and it's bisected down to > > commit 2a8c0883c3cfffcc148ea606e2a4e7453cd75e73 > Author: John Stultz > Date: Fri Jul 13 01:21:56 2012 -0400 > > time: Move xtime_nsec adjustment underflow handling timekeeping_adjust > > [ 8.340327] Freeing unused kernel memory: 460k freed > [ 1107.515496] [sched_delayed] sched: RT throttling activated > [ 1107.516439] BUG: soft lockup - CPU#1 stuck for 1024s! [swapper/1:0] Thanks so much for sending this. One detail I'm curious about is that these kernels from the Bug messages seem to be v3.6-rc1 or earlier. Ingo had a fix 1d17d17484d40f2d5b35c79518597a2b25296996 ("time: Fix adjustment cleanup bug in timekeeping_adjust") that landed in 3.6-rc2 Has this issue actually been seen on a 3.6-rc2+ kernel? thanks -john