[RFC PATCH 2/3] xfs: fix xfsaild hang due to premature idle

[Brian Foster]

On 05/21/2012 02:12 PM, Ben Myers wrote:
> Hey Brian,
> 
> On Mon, May 21, 2012 at 01:21:25PM -0400, Brian Foster wrote:
>> Running xfstests 273 in a loop reproduces an XFS lockup due to
>> xfsaild entering idle mode indefinitely. The following
>> high-level sequence of events leads to the hang:
>>
>> - xfsaild is running, hits the stuck item threshold and reschedules,
>>   setting xa_last_pushed_lsn appropriately.
>> - xa_threshold is updated.
>> - xfsaild restarts from the previous xa_last_pushed_lsn, hits the
>>   new target and enters idle mode, even though the previously
>>   stuck items still populate the ail.
>>
>> Modify the tout logic to only enter idle mode when the ail is empty.
>> IOW, if we hit the target but did not perform the current scan from
>> the start of the ail, reschedule at least one more time.
>>
>> Signed-off-by: Brian Foster <bfoster at redhat.com>
> 
> Thanks for the patch.  Unfortunately it does not apply cleanly.  Care to spin it again?
> 

Hmm... thought I rebased, but apparently not. Sorry about that, I'll repost...

Brian

> Regards,
> 	Ben