Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755307AbYCVQd4 (ORCPT ); Sat, 22 Mar 2008 12:33:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753133AbYCVQds (ORCPT ); Sat, 22 Mar 2008 12:33:48 -0400 Received: from www.tglx.de ([62.245.132.106]:32793 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753003AbYCVQds (ORCPT ); Sat, 22 Mar 2008 12:33:48 -0400 Date: Sat, 22 Mar 2008 17:32:49 +0100 (CET) From: Thomas Gleixner To: Gabriel C cc: Gabriel C , "Rafael J. Wysocki" , LKML , Adrian Bunk , Andrew Morton , Linus Torvalds , Natalie Protasevich , andi-bz@firstfloor.org, Ingo Molnar Subject: Re: 2.6.25-rc5-git6: Reported regressions from 2.6.24 In-Reply-To: <47E5221B.5040900@frugalware.org> Message-ID: References: <200803170018.52663.rjw@sisk.pl> <47DDB969.1060200@googlemail.com> <47DEB65A.9080907@googlemail.com> <47DF3E8B.6040502@googlemail.com> <47E3D322.1090902@googlemail.com> <47E3E66F.9040006@frugalware.org> <47E3FA4F.9060509@frugalware.org> <47E40B1C.30407@frugalware.org> <47E420C5.1050407@frugalware.org> <47E42FAB.6000906@frugalware.org> <47E50AF9.5070801@frugalware.org> <47E5221B.5040900@frugalware.org> User-Agent: Alpine 1.00 (LFD 882 2007-12-20) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1593 Lines: 40 On Sat, 22 Mar 2008, Gabriel C wrote: > Thomas Gleixner wrote: > > On Sat, 22 Mar 2008, Gabriel C wrote: > > > Now some time later CPU1 gets woken by an interrupt/IPI and runs the > >>> timer wheel. At this point the pm_timer which is the reference clock > >>> has already wrapped around, so the watchdog thinks that there is a > >>> huge time difference and marks the TSC unstable. > >>> > >>> Aside of that watchdog issue this also affects the other users of > >>> add_timer_on(): e.g. queue_delayed_work_on(). > >>> > >>> Can you please apply the patch below and verify it with Andi's > >>> watchdog patch applied ? > >> > >> Did that , git head , Andi's + your patch but TSC is still marked unstable. > > > > Doh, stupid me. We do not reevaluate the timer wheel, when we just > > wake up via the smp_reschedule IPI when the resched flag on the other > > CPU is not set. That's a separate vector which is not going through > > irq_enter() / irq_exit(). > > > > Does the patch below solve the problem ? > > With this one TSC is fine but now I get a warning on boot : Good. It confirms my assumptions about the root cause. > [ 0.041037] ------------[ cut here ]------------ > [ 0.041052] WARNING: at arch/x86/kernel/smp_32.c:562 native_smp_call_function_mask+0x23/0x11e() Grr. I'll work out a solution for that one. Thanks, tglx -- 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/