Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752220AbYLMS6g (ORCPT ); Sat, 13 Dec 2008 13:58:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751251AbYLMS60 (ORCPT ); Sat, 13 Dec 2008 13:58:26 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:40885 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750919AbYLMS60 (ORCPT ); Sat, 13 Dec 2008 13:58:26 -0500 From: "Rafael J. Wysocki" To: "Fabio Comolli" Subject: Re: [Bug #12155] Regression in 2.6.28-rc and 2.6.27-stable - hibernate related Date: Sat, 13 Dec 2008 19:56:02 +0100 User-Agent: KMail/1.9.9 Cc: "Linux Kernel Mailing List" , "Kernel Testers List" , "Dave Kleikamp" , Peter Zijlstra , Ingo Molnar , "Greg Kroah-Hartman" , Chuck Ebbert , Linus Torvalds References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200812131956.03495.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2634 Lines: 64 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? Rafael -- 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/