[PATCH V2] XFS: Don't wake xfsbufd when idle

[Alex Elder]

Dave Chinner wrote:
> On Thu, Jan 14, 2010 at 10:51:25AM -0600, Alex Elder wrote:
>> Dave Chinner wrote:
>>> The xfsbufd wakes every xfsbufd_centisecs (once per second by
>>> default) for each filesystem even when the filesystem is idle.
>>> If the xfsbufd has nothing to do, put it into a long term sleep
>>> and only wake it up when there is work pending (i.e. dirty
>>> buffers to flush soon). This will make laptop power misers happy.
>> 
>> Patch generally looks good but I have a question, below.
> 
>>>  	do {
>>> +		long	age = xfs_buf_age_centisecs * msecs_to_jiffies(10);
>>> +		long	tout = age;
>> 
>> Why do you switch from using xfs_buf_timer_centisecs to
>> using xfs_buf_age_centisecs for the timeout (in the non-empty
>> delwrite queue case)?
> 
> Because it's a bug? It should be xfs_buf_timer_centisecs
> here. Good catch, Alex. :)
> 
> Updated patch below
> 
> Cheers,
> 
> Dave.

Looks good.

Reviewed-by: Alex Elder <aelder at sgi.com>