From mboxrd@z Thu Jan  1 00:00:00 1970
From: Gleb Natapov <gleb@redhat.com>
Subject: Re: [Ilw] iwlagn and kvm related "BUG: scheduling while atomic"
 after resuming
Date: Tue, 19 Jul 2011 12:18:50 +0300
Message-ID: <20110719091850.GR2400@redhat.com>
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Cc: Stefan Hajnoczi <stefanha@gmail.com>,
	"Berg, Johannes" <johannes.berg@intel.com>,
	kvm <kvm@vger.kernel.org>,
	Intel Linux Wireless <ilw@linux.intel.com>
To: Avi Kivity <avi@redhat.com>
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On Tue, Jul 19, 2011 at 12:16:54PM +0300, Avi Kivity wrote:
> On 07/19/2011 12:13 PM, Gleb Natapov wrote:
> >>  Preemption is still disabled at this point.  Where does the
> >>  "scheduling while atomic" come from?  Nothing in this area attempts
> >>  to schedule.
> >>
> >0x10000000 in preemption counter is PREEMPT_ACTIVE, so this looks like
> >preemptable kernel tries to preempt itself.
> >
> 
> Yes, it's the wlan interrupt comming after local_irq_enable().  But
> it still doesn't make sense.  We're in a preempt_disable() section,
> so the scheduler shouldn't have been called in the first place.
> 
Yes, and soft irq depth count should prevent that too. Very strange.

--
			Gleb.