Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752831AbYLUWns (ORCPT ); Sun, 21 Dec 2008 17:43:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751439AbYLUWnj (ORCPT ); Sun, 21 Dec 2008 17:43:39 -0500 Received: from rn-out-0910.google.com ([64.233.170.191]:25321 "EHLO rn-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750963AbYLUWni (ORCPT ); Sun, 21 Dec 2008 17:43:38 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=sk6HkHvlNs0mVNZ6Um89koVDgi20TfBu/ogz11ntvasR3nfKgJzx10jy403nR7RiFM goiwE/bt7M5QNV5FZvcfp74JH/Xw7ROE8Cu13nNB6g1JvzHrk1riFwlftNlSuIHFOgNv V6pfsbS0Su7Z4O29w4DtVHZG07azhkbMKInAM= Message-ID: Date: Sun, 21 Dec 2008 23:43:36 +0100 From: "Fabio Comolli" To: "Thomas Gleixner" Subject: Re: TSC not updating after resume: Bug or Feature? Cc: "Rafael J. Wysocki" , "Ingo Molnar" , "Peter Zijlstra" , "Steven Rostedt" , dsaxena@plexity.net, linux-kernel@vger.kernel.org, "Dave Kleikamp" In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20081217172758.GA6010@trantor.hsd1.or.comcast.net> <1229592279.9487.133.camel@twins> <20081218123924.GH25715@elte.hu> <200812182319.57235.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2473 Lines: 64 Hi Thomas. On Sun, Dec 21, 2008 at 8:43 PM, Thomas Gleixner wrote: > On Sun, 21 Dec 2008, Thomas Gleixner wrote: >> On Thu, 18 Dec 2008, Rafael J. Wysocki wrote: >> > > 5b7dba4: sched_clock: prevent scd->clock from moving backwards >> > > >> > > and the bug triggered by hibernation fixed instead. >> >> Hmm. Depending on the hibernation sleep time we can end up with a >> pretty long delta between the pre suspend and the post resume call to >> __update_sched_clock(). >> >> I have the feeling that sched_clock looks into stale values after >> resume and the first call to __update_sched_clock() trips over the >> stale scd->clock value. Shaggy's patch brings scd->clock into the mix >> and that might cause the whole machinery to blow up on resume. >> >> Also we need to investigate whether sched_clock is referencing gtod >> values _before_ timekeeping is resume. > > I checked the two bugzillas (12149 & 12155) and both reporters have > hpet=force on the command line. Well, I'm the submitter of bug 12155 and I never had hpet=force on my command line. I don't know where you found it. Actually my command line is: ------------------------------------------------------------------------------------------------------------------------- fcomolli@hawking:~> cat /proc/cmdline root=/dev/sda2 resume=/dev/sda3 i8042.nomux=1 pciehp.pciehp_force=1 quiet splash=silent vga=791 ------------------------------------------------------------------------------------------------------------------------- By the way, I don't know if it matters but the problema happened with in-kernel hibernation and also in out-of-tree TuxOnIce hibernation. Maybe this can help debugging the issue, I don't know. > > One of the reporters said: "If I de-select CONFIG_HPET_TIMER then the > issue went away ..." > > It looks like this was not further investigated. Is this problem > reproducible on other systems as well ? > > Thanks, > > tglx > -- Regards, Fabio > 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/ > -- 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/