Re: deadlocked xfs

[Eric Sandeen <sandeen@sandeen.net>]

Mark Goodwin wrote:
> Thanks for the report Eric. This looks very similar to a
> deadlock Lachlan recently hit in the patch for
> "Use atomics for iclog reference counting"
> http://oss.sgi.com/archives/xfs/2008-02/msg00130.html
> 
> It seems this patch can cause deadlocks under heavy log traffic.
> I don't think anyone has a fix yet ... Lachlan is out this week,
> but Tim can follow-up here ...

thanks I'll look into that.

Forgot to mention this was on 2.6.26-rc2

-Eric

> Cheers
> -- Mark
> 
> Eric Sandeen wrote:
>> while running fs_mark:
>>
>> fs_mark -d /mnt/test -D 256 -n 100000 -t 4 -s 20480 -F -S 0
>>
>> which runs 4 threads making 20k files,things got stuffed up in the log,
>> see sysrq-w output at:
>>
>> http://sandeen.fedorapeople.org/xfs/deadxfs
>>
>> 2 threads down this path:
>>
>>  [<ffffffffa03c89f5>] :xfs:xlog_state_get_iclog_space+0x83/0x187
>>  [<ffffffffa03c8c1a>] :xfs:xlog_write+0x121/0x486
>>  [<ffffffffa03c9043>] :xfs:xfs_log_write+0x2a/0x50
>>
>> this is on a 4 cpu AMD.
>>
>> I made the fs with:
>>
>> mkfs.xfs -dsize=1t,agcount=32 -l lazy-count=1 -f /dev/sdb
>>
>> and mounted with:
>>
>> mount -o nobarrier,logbsize=256k,logbufs=8,inode64 /dev/sdb /mnt/test
>>
>> has this been seen before?
>>
>> Thanks,
>>
>> -Eric
>>
>>
>