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Date: Thu, 23 May 2013 12:09:41 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] segfault in aio_bh_poll async.c:80 WAS: Re: kvm
 process disappears
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To: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
Cc: Josh Durgin <josh.durgin@inktank.com>, Stefan Hajnoczi <stefanha@gmail.com>, qemu-devel <qemu-devel@nongnu.org>, "pve-devel@pve.proxmox.com" <pve-devel@pve.proxmox.com>, Michael Roth <mdroth@linux.vnet.ibm.com>

Il 22/05/2013 14:24, Stefan Priebe - Profihost AG ha scritto:
> Am 22.05.2013 um 10:41 schrieb Paolo Bonzini <pbonzini@redhat.com>:
> 
>> Il 22/05/2013 08:26, Stefan Priebe - Profihost AG ha scritto:
>>>> Hi,
>>>>
>>>> as i can't reproduce no ;-( i just saw the kernel segfault message and
>>>> used addr2line and a qemu dbg package to get the code line.
>>>
>>> I've now seen this again for two or three times. It always happens
>>> when we do an fstrim inside the guest.
>>
>>
>>> And I've seen this first since josh async rbd patch.
>>
>> This one?
>>
>> commit dc7588c1eb3008bda53dde1d6b890cd299758155
> 
> Yes. But i'm not sure whether this is coincendence.

Ok.

>>  Do you see it even with "-drive discard=off"?
>
> I use discard / trim for thin provisioning and need it. This is a
> production system so I can't test without it.
> 
> I use scsi virtio with discard_granularity=512

Note that 1.5.0 won't need this anymore, but it will need "-drive
discard=on".  Any chance you can try to reproduce it in a different
environment?

Paolo