From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932699AbbFEMHV (ORCPT ); Fri, 5 Jun 2015 08:07:21 -0400 Received: from www.linutronix.de ([62.245.132.108]:35203 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751748AbbFEMHQ (ORCPT ); Fri, 5 Jun 2015 08:07:16 -0400 Date: Fri, 5 Jun 2015 14:07:12 +0200 (CEST) From: Thomas Gleixner To: Prarit Bhargava cc: Richard Cochran , Peter Zijlstra , John Stultz , Ingo Molnar , lkml , Daniel Bristot de Oliveira , Jan Kara , Jiri Bohac , Ingo Molnar , Shuah Khan Subject: Re: [RFC][PATCH 4/4] time: Do leapsecond adjustment in gettime fastpaths In-Reply-To: <55718A00.5010208@redhat.com> Message-ID: References: <1432931068-4980-1-git-send-email-john.stultz@linaro.org> <1432931068-4980-5-git-send-email-john.stultz@linaro.org> <20150602090154.GA2590@gmail.com> <20150603090452.GA9490@gmail.com> <20150604064809.GA14685@gmail.com> <20150605072913.GD19282@twins.programming.kicks-ass.net> <20150605090433.GC1528@localhost.localdomain> <55718A00.5010208@redhat.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 5 Jun 2015, Prarit Bhargava wrote: > > > On 06/05/2015 05:04 AM, Richard Cochran wrote: > > On Fri, Jun 05, 2015 at 09:29:13AM +0200, Peter Zijlstra wrote: > >> That leaves the question; for who is this exact second edge important? > > > > Distributed applications using the UTC time scale. > > > > Many control applications are done with a 1 millisecond period. > > Having the time wrong by a second for 10 or 100 loops is bad news. Control applications with a 1ms period running on CLOCK_REALTIME are broken by definition. > > > > Anything starting @ UTC midnight (I think that would be Beijing, China?) ... > being one second off is not good. > > P. > > > Thanks, > > Richard > > >