From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 24 Apr 2013 21:49:52 -0700 From: Guenter Roeck To: Li Zefan Cc: Prarit Bhargava , John Stultz , linux-kernel@vger.kernel.org, Thomas Gleixner , stable Subject: Re: [PATCH] hrtimer, add expiry time overflow check in hrtimer_interrupt Message-ID: <20130425044952.GA17412@roeck-us.net> References: <1365425235-26191-1-git-send-email-prarit@redhat.com> <5163264B.3050707@linaro.org> <516329D2.1050003@redhat.com> <20130424224218.GA7767@roeck-us.net> <5178890E.9090201@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5178890E.9090201@huawei.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: On Thu, Apr 25, 2013 at 09:38:22AM +0800, Li Zefan wrote: > On 2013/4/25 6:42, Guenter Roeck wrote: > > On Mon, Apr 08, 2013 at 04:34:26PM -0400, Prarit Bhargava wrote: > >> > >> > >> On 04/08/2013 04:19 PM, John Stultz wrote: > >>> On 04/08/2013 05:47 AM, Prarit Bhargava wrote: > >> > >>>> > >>>> A simple check for an overflow can resolve this problem. Using KTIME_MAX > >>>> instead of the overflow value will result in the hrtimer function being run, > >>>> and the reprogramming of the timer after that. > >>>> > >>>> Signed-off-by: Prarit Bhargava > >>>> Cc: Thomas Gleixner > >>>> Cc: John Stultz > >>> > >>> Prarit: Should this be tagged for -stable? > >> > >> John, > >> > >> Yes, this should go to -stable. cc'd. > >> > > Hi, > > > > I am a bit surprised that this patch has not found its way into mainline yet, > > as everyone seems to agree that it is a candidate for -stable. > > > > I hit this problem very reliably (ie with each boot) with 3.8.x on systems > > which have no RTC and run systemd. Seen with Freescale P5040 as well as > > a Broadcom MIPS based system. > > > > FYI, we also hit this warning with 3.4-rt. > You are lucky if it is just a warning for you. In my case the system is reliably dead. Guess there are not (yet) many users out there using systemd (or something similar) on a system with no RTC. While I am not too happy about the delay to get the patch integrated, I am glad that Prarit found and fixed the problem. Saved me a lot of time. Guenter