From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2992607AbXCWX2Y (ORCPT ); Fri, 23 Mar 2007 19:28:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2992630AbXCWX2Y (ORCPT ); Fri, 23 Mar 2007 19:28:24 -0400 Received: from www.osadl.org ([213.239.205.134]:51725 "EHLO mail.tglx.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2992607AbXCWX2O (ORCPT ); Fri, 23 Mar 2007 19:28:14 -0400 Subject: Re: [4/5] 2.6.21-rc4: known regressions (v2) From: Thomas Gleixner Reply-To: tglx@linutronix.de To: Chuck Ebbert Cc: Adrian Bunk , Linus Torvalds , Andrew Morton , Linux Kernel Mailing List , Ingo Molnar , David L , john stultz In-Reply-To: <1174689791.10840.377.camel@localhost.localdomain> References: <20070323185028.GR752@stusta.de> <1174677338.10840.321.camel@localhost.localdomain> <46045355.1020105@redhat.com> <1174689791.10840.377.camel@localhost.localdomain> Content-Type: text/plain Date: Sat, 24 Mar 2007 00:35:36 +0100 Message-Id: <1174692936.10840.392.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2007-03-23 at 23:43 +0100, Thomas Gleixner wrote: > On Fri, 2007-03-23 at 18:23 -0400, Chuck Ebbert wrote: > > Thomas Gleixner wrote: > > > On Fri, 2007-03-23 at 19:50 +0100, Adrian Bunk wrote: > > >> Subject : gettimeofday increments too slowly > > >> References : http://bugzilla.kernel.org/show_bug.cgi?id=8027 > > >> Submitter : David L > > >> Caused-By : Thomas Gleixner > > >> commit 92c7e00254b2d0efc1e36ac3e45474ce1871b6b2 > > >> Handled-By : Thomas Gleixner > > >> Status : problem is being debugged > > > > > > Patch available: http://lkml.org/lkml/2007/3/22/301 > > > > > > commit 6b3964cde70cfe6db79d35b42137431ef7d2f7e4 > > > > > > > For the other issue raised there, clock running too slow, I now > > realize there is a similar report: > > > > https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=231626 > > That's a different one, AFAICT. Davids problem is probably caused by me > breaking the TSC watchdog. > > /me orders paperbags prophylactically and goes back to look at the code David, can you please test the patch below ? tglx ---------------------> Subject: [PATCH] clocksource: Fix thinko in watchdog selection The watchdog implementation excludes low res / non continuous clocksources from being selected as a watchdog reference unintentionally. Allow using jiffies/PIT as a watchdog reference as long as no better clocksource is available. This is necessary to detect TSC breakage on systems, which have no pmtimer/hpet. The main goal of the initial patch (preventing to switch to highres/nohz when no reliable fallback clocksource is available) is still guaranteed by the checks in clocksource_watchdog(). Signed-off-by: Thomas Gleixner diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 5b0e46b..fe5c7db 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -151,7 +151,8 @@ static void clocksource_check_watchdog(struct clocksource *cs) watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL; add_timer(&watchdog_timer); } - } else if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) { + } else { + if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES; if (!watchdog || cs->rating > watchdog->rating) {