On 07/24/2011 10:14 AM, Maciej Rutecki wrote:
> On czwartek, 21 lipca 2011 o 22:55:04 Török Edwin wrote:
>> Hi,
>>
>> Just got this BUG in my dmesg:
>> [47504.938446] BUG: unable to handle kernel paging request at
>> ffff884058ec3270 [47504.938488] IP: [<ffffffff8127baf1>]
> [...]
> 
> 2.6.39 works OK?. It is regression?

I don't know, I was not able to reproduce the bug on 3.0 either.
Either the bug was fixed between 3.0-rc7 and 3.0, or it is very hard to reproduce.

I tried with the attached test program (which creates a mess^H some files in the current directory, performs I/O and dumps core
from 2 processes in parallel.).

All I got was 2 hung kernel threads for 2m+ in xfs_evict_inode + xfs_file_sync, trigerring the hung_check timer and NMI backtraces,
and the process was unkillable (by kill -9) for a while. It eventually recovered though, and its not surprising that this happened
: the test program generated 100Mb/s - 500Mb/s I/O.

I'll have to see if I can reproduce the BUG with 3.0-rc7. Although I don't see any XFS changes between 3.0-rc7 and 3.0
there were some RCU fixes to core VFS code.

Best regards,
--Edwin