From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frederic Weisbecker Subject: Re: 2.6.35-rc4-git3: Reported regressions from 2.6.34 Date: Fri, 9 Jul 2010 04:04:42 +0200 Message-ID: <20100709020440.GJ6405@nowhere> References: <-IGZ64uxA6G.A.P0H.bLmNMB@chimera> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: Sender: kernel-testers-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Linus Torvalds Cc: "Rafael J. Wysocki" , Linux Kernel Mailing List , Maciej Rutecki , Andrew Morton , Kernel Testers List , Network Development , Linux ACPI , Linux PM List , Linux SCSI List , Linux Wireless List , DRI , Al Viro , Shawn Starr , Jesse Barnes , Dave Airlie , "David S. Miller" , Patrick McHardy , Jens Axboe List-Id: linux-scsi@vger.kernel.org On Thu, Jul 08, 2010 at 06:34:25PM -0700, Linus Torvalds wrote: > On Thu, Jul 8, 2010 at 4:33 PM, Rafael J. Wysocki wrote= : > > Bug-Entry =A0 =A0 =A0 : http://bugzilla.kernel.org/show_bug.cgi?id=3D= 16284 > > Subject =A0 =A0 =A0 =A0 : Hitting WARN_ON in hw_breakpoint code > > Submitter =A0 =A0 =A0 : Paul Mackerras > > Date =A0 =A0 =A0 =A0 =A0 =A0: 2010-06-23 12:57 (16 days old) > > Message-ID =A0 =A0 =A0: <20100623125740.GA3368-oklZEfemRj05kJ7NmlRacFaTQe2KTcn/@public.gmane.org= > > > References =A0 =A0 =A0: http://marc.info/?l=3Dlinux-kernel&m=3D1277= 29789113432&w=3D2 >=20 > This has "I have a fix, will post it very soon." in the thread from > Frederic, but I'm not seeing anything else. Frederic? Right. In fact it wasn't a regression. The per task breakpoint reservat= ion design was broken from the beginning and this warning has revealed the problem. This only touched perf, and it did since perf support breakpoi= nts. =46ortunately ptrace wasn't concerned by this problem, even not by side= effects of this. The fix is invasive as it's a rewrite of a (little) part of the breakpo= int reservation. And since the symptom is only a warning and also breakpoin= ts never released from the constraint table (just a counter, no memory lea= k), the fix is headed for 2.6.36. It is ready in tip:/perf/core: http://git.kernel.org/?p=3Dlinux/kernel/git/tip/linux-2.6-tip.git;a=3Dc= ommitdiff;h=3D45a73372efe4a63f44aa2e1125d4a777c2fdc8d8 I think this ticket can be safely closed. Thanks. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754820Ab0GICE4 (ORCPT ); Thu, 8 Jul 2010 22:04:56 -0400 Received: from mail-ww0-f44.google.com ([74.125.82.44]:48254 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751946Ab0GICEx (ORCPT ); Thu, 8 Jul 2010 22:04:53 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:content-transfer-encoding :in-reply-to:user-agent; b=PzWy6t2cQUxetj/Gfq6GkGxSXOUV4zMzIq53d3jO79G5bZEeYqGLslVGfZ03chqX2I LgNZtzuTuCZCVaXZ+UPEYQgHLZblh4b59F2VpgaHCKHbhYWN+tx9rgxowWLWY5Hs93kG w6E85hurU7KB7f0pOKdkXoZhfupqNgzbf9KvY= Date: Fri, 9 Jul 2010 04:04:42 +0200 From: Frederic Weisbecker To: Linus Torvalds Cc: "Rafael J. Wysocki" , Linux Kernel Mailing List , Maciej Rutecki , Andrew Morton , Kernel Testers List , Network Development , Linux ACPI , Linux PM List , Linux SCSI List , Linux Wireless List , DRI , Al Viro , Shawn Starr , Jesse Barnes , Dave Airlie , "David S. Miller" , Patrick McHardy , Jens Axboe Subject: Re: 2.6.35-rc4-git3: Reported regressions from 2.6.34 Message-ID: <20100709020440.GJ6405@nowhere> References: <-IGZ64uxA6G.A.P0H.bLmNMB@chimera> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 08, 2010 at 06:34:25PM -0700, Linus Torvalds wrote: > On Thu, Jul 8, 2010 at 4:33 PM, Rafael J. Wysocki wrote: > > Bug-Entry       : http://bugzilla.kernel.org/show_bug.cgi?id=16284 > > Subject         : Hitting WARN_ON in hw_breakpoint code > > Submitter       : Paul Mackerras > > Date            : 2010-06-23 12:57 (16 days old) > > Message-ID      : <20100623125740.GA3368@brick.ozlabs.ibm.com> > > References      : http://marc.info/?l=linux-kernel&m=127729789113432&w=2 > > This has "I have a fix, will post it very soon." in the thread from > Frederic, but I'm not seeing anything else. Frederic? Right. In fact it wasn't a regression. The per task breakpoint reservation design was broken from the beginning and this warning has revealed the problem. This only touched perf, and it did since perf support breakpoints. Fortunately ptrace wasn't concerned by this problem, even not by side effects of this. The fix is invasive as it's a rewrite of a (little) part of the breakpoint reservation. And since the symptom is only a warning and also breakpoints never released from the constraint table (just a counter, no memory leak), the fix is headed for 2.6.36. It is ready in tip:/perf/core: http://git.kernel.org/?p=linux/kernel/git/tip/linux-2.6-tip.git;a=commitdiff;h=45a73372efe4a63f44aa2e1125d4a777c2fdc8d8 I think this ticket can be safely closed. Thanks.