Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755360AbZGGGui (ORCPT ); Tue, 7 Jul 2009 02:50:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751150AbZGGGu2 (ORCPT ); Tue, 7 Jul 2009 02:50:28 -0400 Received: from mail-bw0-f225.google.com ([209.85.218.225]:49417 "EHLO mail-bw0-f225.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750920AbZGGGu1 (ORCPT ); Tue, 7 Jul 2009 02:50:27 -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:in-reply-to:user-agent; b=pYMh2I/IvoV+vchJxk7m6QTA7JzuJBjLRXkpRTfwrcHI0i+bEpXauh6R3VXjgl+8oY UNfyMdghhQDi+jzZGCYfhNDDOjlWjDX0Ye3rlF28nKqxyljUXPNHI1cTecxOdFFUt1iV uEtErm9HNoF1UiHps9oZ7tpa1hPA3yVP+1LXs= Date: Tue, 7 Jul 2009 08:50:14 +0200 From: Jarek Poplawski To: Andres Freund Cc: Joao Correia , Arun R Bharadwaj , Thomas Gleixner , Stephen Hemminger , netdev@vger.kernel.org, LKML Subject: Re: Soft-Lockup/Race in networking in 2.6.31-rc1+195 ( possibly?caused by netem) Message-ID: <20090707065014.GA3296@ami.dom.local> References: <200907031326.21822.andres@anarazel.de> <20090706163106.GA4559@ami.dom.local> <200907061926.43625.andres@anarazel.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200907061926.43625.andres@anarazel.de> 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 Content-Length: 1618 Lines: 43 On Mon, Jul 06, 2009 at 07:26:43PM +0200, Andres Freund wrote: > On Monday 06 July 2009 19:23:18 Joao Correia wrote: > > Hello > > > > Since i already had the kernel compiled and ready to boot when i read > > this, i gave it a go anyway :-). > > > > I can reproduce the freeze with those 4 patches applied, so i can > > confirm that its, at least, related to, or exposed by, those patches. > > There must be something else too, or its just too much fuzziness, but > > the freeze takes a bit more time (approximately five minutes, give or > > take) compared to the instant freeze before, but its there with the > > patches, and without them, no freeze. > > > > I assume there isnt a "safe" way to get them out of current .31-rc's, > > right? > `echo 0 > /proc/sys/kernel/timer_migration` should mitigate the problem. I guess it should fix it entirely. Btw., here is a patch disabling the timers' part, so to make it hrtimers only. Could you try? Thanks, Jarek P. --- diff --git a/kernel/timer.c b/kernel/timer.c index 0b36b9e..011429c 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -634,7 +634,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires, cpu = smp_processor_id(); -#if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP) +#if 0 if (!pinned && get_sysctl_timer_migration() && idle_cpu(cpu)) { int preferred_cpu = get_nohz_load_balancer(); -- 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/