From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755498AbbFLOwa (ORCPT ); Fri, 12 Jun 2015 10:52:30 -0400 Received: from arcturus.aphlor.org ([188.246.204.175]:39709 "EHLO arcturus.aphlor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755373AbbFLOw3 (ORCPT ); Fri, 12 Jun 2015 10:52:29 -0400 Date: Fri, 12 Jun 2015 10:52:12 -0400 From: Dave Jones To: John Stultz Cc: linux-kernel@vger.kernel.org, Prarit Bhargava , 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 Message-ID: <20150612145211.GA22489@codemonkey.org.uk> Mail-Followup-To: Dave Jones , John Stultz , linux-kernel@vger.kernel.org, Prarit Bhargava , Daniel Bristot de Oliveira , Richard Cochran , Jan Kara , Jiri Bohac , Thomas Gleixner , Ingo Molnar , Shuah Khan References: <1434063297-28657-1-git-send-email-john.stultz@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1434063297-28657-1-git-send-email-john.stultz@linaro.org> User-Agent: Mutt/1.5.23 (2014-03-12) X-Spam-Score: -2.9 (--) X-Spam-Report: Spam report generated by SpamAssassin on "arcturus.aphlor.org" Content analysis details: (-2.9 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] X-Authenticated-User: davej@codemonkey.org.uk Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 11, 2015 at 03:54:52PM -0700, 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 Any idea how far back this reaches ? Ie, which longterm stable releases might be affected by this ? (It really creeps me out that we're still changing this code so close to the next leap second event). Dave