Re: btrfs deadlock in 3.5-rc3

[Stefan Priebe <s.priebe@profihost.ag>]

With v3.4 the same. Can't go back more as this really results in very 
fast corruption. Any ideas how to debug?

Stefan

Am 25.06.2012 20:28, schrieb Stefan Priebe:
> Am 25.06.2012 20:02, schrieb Josef Bacik:
>>>   >  Can you turn that off and see if you
>>>> can still reproduce the deadlock?  If so sysrq+w again, if not then
>>>> I know where
>>>> to look ;).  Thanks,
>>> without discard i can't reproduce but random write speed with ceph
>>> without discard is a LOT slower (around 8000 iops/s instead of
>>> 13000iops/s). So i don't know if it is discard or if i'm just not able
>>> to trigger it.
>>>
>>
>> Ouch, what kind of drive goes faster with discard _on_?  Anyway it
>> looks like
>> we're waiting for the discard to come back, so either its your drive
>> or theres a
>> bug in the block layer.  Maybe try an older kernel and see if it's
>> broken there,
>> and then bisect it down?  Thanks,
>
> Intel 520 series SSD. I can't try an older kernel version as ceph
> crashes with them pretty fast due to other bugs which where fixed with
> 3.5-rc1.
>
> Greets
> Stefan