Date: Wed, 30 Sep 2009 09:50:43 +0200
From: Michal Schmidt <mschmidt@redhat.com>
To: Yong Zhang <yong.zhang0@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>, Maciej Rutecki <maciej.rutecki@gmail.com>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
       "Rafael J. Wysocki" <rjw@sisk.pl>, clemens@ladisch.de,
       venkatesh.pallipadi@intel.com, gregkh@suse.de
Subject: Re: [2.6.31-git17] WARNING: at kernel/hrtimer.c:648 
 hres_timers_resume+0x40/0x50()/WARNING: at drivers/base/sys.c:353 
 __sysdev_resume+0xc3/0xe0()
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Dne Tue, 29 Sep 2009 17:31:43 +0800
Yong Zhang <yong.zhang0@gmail.com> napsal(a):

> On Tue, Sep 29, 2009 at 3:24 PM, Ingo Molnar <mingo@elte.hu> wrote:
> > Could you try this with .32-rc1? This commit should have fixed the
> > message above:
> >
> > 89133f9: clocksource: Resume clocksource without taking the
> > clocksource mutex
> >
> 
> Hi Ingo,
> 
> Indeed, Maciej said this issue is gone with .32-rc1. But I don't think
> this is the same
> issue with 89133f9 because in this one timekeeping_resume() is called
> with irq enabled.
> This is very odd and the bug exists in other parts.

It is the same issue. Maciej has CONFIG_PREEMPT_VOLUNTARY=y which means
taking the mutex in clocksource_resume() could have called into
schedule(), thus enabling irqs.

Michal
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