From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754927AbbFONqu (ORCPT ); Mon, 15 Jun 2015 09:46:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33375 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750734AbbFONqm (ORCPT ); Mon, 15 Jun 2015 09:46:42 -0400 Message-ID: <557ED740.7030000@redhat.com> Date: Mon, 15 Jun 2015 09:46:40 -0400 From: Prarit Bhargava User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20131028 Thunderbird/17.0.10 MIME-Version: 1.0 To: John Stultz CC: linux-kernel@vger.kernel.org, Daniel Bristot de Oliveira , Richard Cochran , Jan Kara , Jiri Bohac , Thomas Gleixner , Ingo Molnar , Shuah Khan Subject: Re: [PATCH 0/5 v2] Fixes for leapsecond expiring early ABS_TIME CLOCK_REALTIME timers References: <1434063297-28657-1-git-send-email-john.stultz@linaro.org> <557ECEB8.6010804@redhat.com> In-Reply-To: <557ECEB8.6010804@redhat.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 06/15/2015 09:10 AM, Prarit Bhargava wrote: > > > On 06/11/2015 06:54 PM, John Stultz wrote: >> So this is a second round at trying to address the issue, trying >> to integrate feedback from Ingo and Thomas, trying to simplify >> what I can. I've also split out the changes so each can be >> more easily reviewed. Its still not tiny, but its simpler. >> >> This series is against tip/timers/core, and the first patch isn't >> strictly related but is a fix that is needed in tip/timers/core. >> >> As Prarit reported here: >> https://lkml.org/lkml/2015/5/27/458 >> >> Since the leapsecond is applied at timer tick time, and not >> the actual second edge, ABS_TIME CLOCK_REALTIME timers set for >> right after the leapsecond could fire a second early, since >> some timers may be expired before we trigger the timekeeping >> timer, which then applies the leapsecond. >> >> Thus this patch series tries to address this issue, including >> extending the leap-a-day test to catch this problem, as well >> as other relevant fixups I found while working on the code. >> >> This series has only had limited testing, so I wanted to send >> it out for initial review and comment. Folks can grab this tree >> via git for testing here: >> https://git.linaro.org/people/john.stultz/linux.git dev/early-leap-timer >> > > I'm testing this on a few more large CPU count systems. So far, so good ... > John, unfortunately I'm seeing failures across a lot of the large systems dev/early-leap-timer as of this AM [root@intel-chiefriver-04 ~]# systemctl status chronyd chronyd.service - NTP client/server Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled) Active: inactive (dead) since Mon 2015-06-15 09:25:33 EDT; 5s ago Process: 731 ExecStartPost=/usr/libexec/chrony-helper add-dhclient-servers (code=exited, status=0/SUCCESS) Process: 713 ExecStart=/usr/sbin/chronyd -u chrony $OPTIONS (code=exited, status=0/SUCCESS) Main PID: 724 (code=exited, status=0/SUCCESS) CGroup: /system.slice/chronyd.service Jun 15 09:25:06 intel-chiefriver-04.khw.lab.eng.bos.redhat.com chronyd[724]: ... Jun 15 09:25:06 intel-chiefriver-04.khw.lab.eng.bos.redhat.com chronyd[724]: ... Jun 15 09:25:06 intel-chiefriver-04.khw.lab.eng.bos.redhat.com chronyd[724]: ... Jun 15 09:25:06 intel-chiefriver-04.khw.lab.eng.bos.redhat.com chronyd[724]: ... Jun 15 09:25:06 intel-chiefriver-04.khw.lab.eng.bos.redhat.com systemd[1]: St... Jun 15 09:25:19 intel-chiefriver-04.khw.lab.eng.bos.redhat.com chronyd[724]: ... Jun 15 09:25:19 intel-chiefriver-04.khw.lab.eng.bos.redhat.com chronyd[724]: ... Jun 15 09:25:33 intel-chiefriver-04.khw.lab.eng.bos.redhat.com systemd[1]: St... Jun 15 09:25:33 intel-chiefriver-04.khw.lab.eng.bos.redhat.com chronyd[724]: ... Jun 15 09:25:33 intel-chiefriver-04.khw.lab.eng.bos.redhat.com systemd[1]: St... Hint: Some lines were ellipsized, use -l to show in full. [root@intel-chiefriver-04 ~]# ./leap-a-day -s Setting time to speed up testing This runs continuously. Press ctrl-c to stop Setting time to Mon Jun 15 19:59:50 2015 Scheduling leap second for Mon Jun 15 20:00:00 2015 Setting timer for Mon Jun 15 20:00:00 2015 Mon Jun 15 19:59:57 2015 + 18177 us (0) TIME_INS Mon Jun 15 19:59:57 2015 + 526181 us (0) TIME_INS Mon Jun 15 19:59:58 2015 + 37418 us (0) TIME_INS Mon Jun 15 19:59:58 2015 + 546474 us (0) TIME_INS Mon Jun 15 19:59:59 2015 + 55724 us (0) TIME_INS Mon Jun 15 19:59:59 2015 + 566970 us (0) TIME_INS Mon Jun 15 19:59:59 2015 + 6013 us (1) TIME_OOP - TIMER FIRED Error: Early timer expiration! Error: Incorrect NTP state? Mon Jun 15 19:59:59 2015 + 6040 us (1) TIME_OOP Mon Jun 15 19:59:59 2015 + 517240 us (1) TIME_OOP Mon Jun 15 20:00:00 2015 + 28504 us (1) TIME_WAIT Mon Jun 15 20:00:00 2015 + 539745 us (1) TIME_WAIT Mon Jun 15 20:00:01 2015 + 50978 us (1) TIME_WAIT Mon Jun 15 20:00:01 2015 + 560360 us (1) TIME_WAIT Mon Jun 15 20:00:02 2015 + 69952 us (1) TIME_WAIT ERROR: hrtimer early expiration failure observed. Leap complete Errors observed P.