From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932696AbXCKWAh (ORCPT ); Sun, 11 Mar 2007 18:00:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932875AbXCKWAh (ORCPT ); Sun, 11 Mar 2007 18:00:37 -0400 Received: from www17.your-server.de ([213.133.104.17]:4138 "EHLO www17.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932696AbXCKWAg (ORCPT ); Sun, 11 Mar 2007 18:00:36 -0400 Message-ID: <45F47B2D.1090403@m3y3r.de> Date: Sun, 11 Mar 2007 22:57:01 +0100 From: Thomas Meyer User-Agent: Thunderbird 1.5.0.10 (X11/20070302) MIME-Version: 1.0 To: tglx@linutronix.de CC: "Rafael J. Wysocki" , Milan Broz , Andrew Morton , linux-kernel@vger.kernel.org, Pavel Machek Subject: Re: SwSusp to disk doesn't work - Try 2 References: <45F44599.3060508@m3y3r.de> <45F46660.4010102@m3y3r.de> <45F46D33.1050808@redhat.com> <200703112209.53665.rjw@sisk.pl> <1173650195.13341.11.camel@localhost.localdomain> In-Reply-To: <1173650195.13341.11.camel@localhost.localdomain> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated-Sender: thomas@m3y3r.de Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Thomas Gleixner schrieb: > On Sun, 2007-03-11 at 22:09 +0100, Rafael J. Wysocki wrote: > >>>>>>>> update_sched_domains >>>>>>>> detach_destroy_domains >>>>>>>> [waits here] --> synchronize_sched (==synchronize_rcu) >>>>>>>> >>>>>>>> >>>>>>> Well, I think the call to wait_for_completion() does not return, probably >>>>>>> because the task supposed to complete the completion is frozen at this >>>>>>> point. Can you please try to confirm that it gets stuck on >>>>>>> wait_for_completion() in synchronize_rcu()? >>>>>>> >>>>>>> >>>>>> Yes, it's in wait_for_completion() in synchronize_rcu(). >>>>>> As noted in some previous mail, it will wake up after >>>>>> event - key press etc. >>>>>> >>>>>> Patch in http://lkml.org/lkml/2007/3/7/255 solves different problem. >>>>>> I added it to my quilt and applied anyway -> no change. >>>>>> >>>>>> >>>>> Does the problem go away if NO_HZ is unset? >>>>> >>>>> >>>> i tried to boot with nohz=off, but the problem did persist. >>>> >>> Hmmmm, both variants (nohz=off or recompiled kernel without NO_HZ) works for me. >>> >> Definitely something strange is going on here. >> >> I think we need an advice from someone who knows the RCU internals. >> > > RCU synchronization depends on the timer interrupt. Which kernel version > are you guys talking about ? > > tglx > I talk about be521466feb3bb1cd89de82a2b1d080e9ebd3cb6 (2.6.21-rc3+). The worst config is with nohz and without hrtimers: the kernel even doesn't come back after pressing the power key. But i stay with without nohz and without hrtimers for now, because here the suspend to disk works.