From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932874Ab2GEO3n (ORCPT ); Thu, 5 Jul 2012 10:29:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38069 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751191Ab2GEO3l (ORCPT ); Thu, 5 Jul 2012 10:29:41 -0400 Message-ID: <4FF5A4CC.3050302@redhat.com> Date: Thu, 05 Jul 2012 10:29:32 -0400 From: Prarit Bhargava User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110419 Red Hat/3.1.10-1.el6_0 Thunderbird/3.1.10 MIME-Version: 1.0 To: John Stultz CC: Linux Kernel , stable@vger.kernel.org, Thomas Gleixner , linux@openhuawei.org Subject: Re: [PATCH 2/3] [RFC] time: Fix leapsecond triggered hrtimer/futex load spike issue References: <1341382890-42324-1-git-send-email-johnstul@us.ibm.com> <1341382890-42324-3-git-send-email-johnstul@us.ibm.com> In-Reply-To: <1341382890-42324-3-git-send-email-johnstul@us.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/04/2012 02:21 AM, John Stultz wrote: > As widely reported on the internet, some Linux systems after > the leapsecond was inserted are experiencing futex related load > spikes (usually connected to MySQL, Firefox, Thunderbird, Java, etc). > > An apparent for this issue workaround is running: > $ date -s "`date`" > > Credit: http://www.sheeri.com/content/mysql-and-leap-second-high-cpu-and-fix > > I this issue is due to the leapsecond being added without > calling clock_was_set() to notify the hrtimer subsystem of the > change. > > The workaround functions as it forces a clock_was_set() > call from settimeofday(). > > This fix adds the required clock_was_set() calls to where > we adjust for leapseconds. > > NOTE: This fix *depends* on the previous fix, which allows > clock_was_set to be called from atomic context. Do not try > to apply just this patch. > > CC: Prarit Bhargava > CC: stable@vger.kernel.org > CC: Thomas Gleixner > CC: linux@openhuawei.org > Reported-by: Jan Engelhardt > Signed-off-by: John Stultz Acked-by: Prarit Bhargava P.