From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1947399Ab3BHXo5 (ORCPT ); Fri, 8 Feb 2013 18:44:57 -0500 Received: from mx1.redhat.com ([209.132.183.28]:24311 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1947361Ab3BHXo4 (ORCPT ); Fri, 8 Feb 2013 18:44:56 -0500 Message-ID: <51158DF2.3090702@redhat.com> Date: Fri, 08 Feb 2013 18:44:50 -0500 From: Prarit Bhargava User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110419 Red Hat/3.1.10-1.el6_0 Thunderbird/3.1.10 MIME-Version: 1.0 To: John Stultz 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> In-Reply-To: <51158643.1020204@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 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. If you want me to do some other test I certainly can give it a shot. P.