From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758808AbYD2G7b (ORCPT ); Tue, 29 Apr 2008 02:59:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753736AbYD2G7X (ORCPT ); Tue, 29 Apr 2008 02:59:23 -0400 Received: from viefep18-int.chello.at ([213.46.255.22]:53186 "EHLO viefep19-int.chello.at" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753685AbYD2G7X (ORCPT ); Tue, 29 Apr 2008 02:59:23 -0400 Subject: Re: [BUG-REPORT] hrtick_start_fair and CPU-Hotplug From: Peter Zijlstra To: ego@in.ibm.com Cc: Ingo Molnar , Dhaval Giani , Srivatsa Vaddagiri , Balbir Singh , linux-kernel@vger.kernel.org In-Reply-To: <20080429065211.GB7859@in.ibm.com> References: <20080429065211.GB7859@in.ibm.com> Content-Type: text/plain Date: Tue, 29 Apr 2008 08:59:19 +0200 Message-Id: <1209452359.13978.26.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.22.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2008-04-29 at 12:22 +0530, Gautham R Shenoy wrote: > Hello! > > While running the usual CPU-Hotplug stress tests on linux-2.6.25, > I noticed the following in the console logs. > > This is a wee bit difficult to reproduce. In the past 10 runs I hit this > only once. > > ------------[ cut here ]------------ > > WARNING: at kernel/sched.c:962 hrtick+0x2e/0x65() > I am not well versed with this part of the code, so just wondering if we > are doing a good job at handling the cancellation of any per-cpu > scheduler timers during CPU-Hotplug. This looks like its not cancelled at all and migrates the it to another cpu. I'll see what I can come up with.