From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1947441Ab3BHXu6 (ORCPT ); Fri, 8 Feb 2013 18:50:58 -0500 Received: from mail-ie0-f176.google.com ([209.85.223.176]:52136 "EHLO mail-ie0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1947395Ab3BHXu5 (ORCPT ); Fri, 8 Feb 2013 18:50:57 -0500 Message-ID: <51158F5E.9000007@linaro.org> Date: Fri, 08 Feb 2013 15:50:54 -0800 From: John Stultz User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: Prarit Bhargava CC: linux-kernel@vger.kernel.org, Thomas Gleixner Subject: Re: [PATCH] time, Fix setting of hardware clock in NTP code References: <1360364393-17595-1-git-send-email-prarit@redhat.com> <51158643.1020204@linaro.org> <51158DF2.3090702@redhat.com> In-Reply-To: <51158DF2.3090702@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/08/2013 03:44 PM, Prarit Bhargava wrote: > > On 02/08/2013 06:12 PM, John Stultz wrote: >> On 02/08/2013 02:59 PM, Prarit Bhargava wrote: >> Ok, I've got this queued in my tree. What sort of testing did you do with it? >> >> I want to make sure we don't run into any bad interactions with the existing >> 15min cap on x86. > John, > > I did the following: > > I used powerpc pseries systems and tested this using both positive and negative > values of sys_tz.minuteswest, with both UTC and LOCAL in /etc/adjtime. I dumped > values of 'hwclock -D' and date and confirmed that I no longer see time > increasing by sys_tz.minuteswest each reboot. > > I also tested x86 32-bit and 64-bit as a sanity check and verified that the > current behaviour on those arches is the same; ie) I don't see *any* impact to > the x86 rtc. I dumped values of 'hwclock -D' and date, and again confirmed that > I see no differences in values. I did that with both UTC and LOCAL. > > I also tested a powerpc box and set the hwclock (via BIOS) back to Dec 6 2012 to > see what would happen when I enabled ntp. The system booted, set the system > time to Dec 6 2012, and then properly ended up with both system time AND hwclock > as Feb 8 2013 after systemd init .... (The *exact* time-of-day was correct as > well. I just can't remember the time I did it ;) ) > > And I did the same thing (adjusting the BIOS date back) on x86. I only see the > hours and minutes change, as we expect. The year, month, day are unaffected > with both UTC and LOCAL. > > tl;dr Yup. Tested as much as I could think of doing before submitting. Tested > on a both x86, powerpc. Fixed the bug on powerpc. No change in behavior seen > with x86. Great! This is perfect! Thanks for being so thorough! -john