Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756890AbYLPTH7 (ORCPT ); Tue, 16 Dec 2008 14:07:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754511AbYLPTHq (ORCPT ); Tue, 16 Dec 2008 14:07:46 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:43479 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755602AbYLPTHp (ORCPT ); Tue, 16 Dec 2008 14:07:45 -0500 Date: Tue, 16 Dec 2008 20:07:07 +0100 From: Ingo Molnar To: "Rafael J. Wysocki" Cc: Fabio Comolli , Linux Kernel Mailing List , Kernel Testers List , Dave Kleikamp , Peter Zijlstra , Greg Kroah-Hartman , Chuck Ebbert , Linus Torvalds Subject: Re: [Bug #12155] Regression in 2.6.28-rc and 2.6.27-stable - hibernate related Message-ID: <20081216190707.GA336@elte.hu> References: <200812131956.03495.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200812131956.03495.rjw@sisk.pl> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2849 Lines: 67 * Rafael J. Wysocki wrote: > On Saturday, 13 of December 2008, Fabio Comolli wrote: > > Hi. > > Hi, > > > On Sat, Dec 13, 2008 at 5:33 PM, Rafael J. Wysocki wrote: > > > This message has been generated automatically as a part of a report > > > of recent regressions. > > > > > > The following bug entry is on the current list of known regressions > > > from 2.6.27. Please verify if it still should be listed and let me know > > > (either way). > > > > > > > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=12155 > > > Subject : Regression in 2.6.28-rc and 2.6.27-stable - hibernate related > > > Submitter : Fabio Comolli > > > Date : 2008-11-23 16:17 (21 days old) > > > References : http://marc.info/?l=linux-kernel&m=122745709926361&w=4 > > > > Still present. It has been bisected to: > > > > --------------------------------------------------------------------------------------------------------------- > > commit 5e55aa8db085dad1aabb4574c73c23c7ae571e7b > > Author: Dave Kleikamp > > Date: Sun Oct 26 18:20:14 2008 -0400 > > > > sched_clock: prevent scd->clock from moving backwards > > > > commit 5b7dba4ff834259a5623e03a565748704a8fe449 upstream > > > > sched_clock: prevent scd->clock from moving backwards > > > > When sched_clock_cpu() couples the clocks between two cpus, it may > > increment scd->clock beyond the GTOD tick window that __update_sched_clock() > > uses to clamp the clock. A later call to __update_sched_clock() may move > > the clock back to scd->tick_gtod + TICK_NSEC, violating the clock's > > monotonic property. > > > > This patch ensures that scd->clock will not be set backward. > > > > Signed-off-by: Dave Kleikamp > > Acked-by: Peter Zijlstra > > Signed-off-by: Ingo Molnar > > Cc: Chuck Ebbert > > Signed-off-by: Greg Kroah-Hartman > > ------------------------------------------------------------------------------------------------------------ > > > > Both 2.6.27.8 and 2.6.28-rc8 with that commit reverted work fine > > (well, at least they failed to show the bug so far). > > Thanks for the update, I have put this information into the Bugzilla entry. > > Would everyone involved agree with reverting the above commit for now > and revisiting the issue in the 2.6.29 time frame? yeah - i think it's too late to do anything but a revert here. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/