From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753144AbbFAL6E (ORCPT ); Mon, 1 Jun 2015 07:58:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48335 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753003AbbFAL5w (ORCPT ); Mon, 1 Jun 2015 07:57:52 -0400 Message-ID: <556C48BD.9010201@redhat.com> Date: Mon, 01 Jun 2015 07:57:49 -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: lkml , Daniel Bristot de Oliveira , Richard Cochran , Jan Kara , Jiri Bohac , Thomas Gleixner , Ingo Molnar , Shuah Khan Subject: Re: [RFC][PATCH 0/4] Fixes for leapsecond expiring early ABS_TIME CLOCK_REALTIME timers References: <1432931068-4980-1-git-send-email-john.stultz@linaro.org> In-Reply-To: <1432931068-4980-1-git-send-email-john.stultz@linaro.org> 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 05/29/2015 04:24 PM, John Stultz wrote: > 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 isssue, 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 > John, native testing went well across many 32-bit and 64-bit AMD and Intel boxes. However, virtual (specifically KVM) guests failed with some sort of corruption: [ 1546.038479] Clock: inserting leap second 23:59:60 UTC [ 1559.774700] Clock: inserting leap second 23:59:60 UTC [ 1573.502989] Clock: inserting leap second 23:59:60 UTC [ 1587.235917] Clock: inserting leap second 23:59:60 UTC [ 7. X] Clock: inserting leap second 23:59:60 UTC [ 7. X] Clock: inserting leap second 23:59:60 UTC [ 7. X] Clock: inserting leap second 23:59:60 UTC [ 7. X] Clock: inserting leap second 23:59:60 UTC I'm going to see if I can figure out a way to kdump a guest with this problem. The issue is that it seems like all input to the console is ignored when this happens. P.