Re: [PATCH] xfs: force background CIL push under sustained load

[Alex Elder <aelder@xxxxxxx>]

On Thu, 2010-09-23 at 12:27 +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@xxxxxxxxxx>
> 
> I have been seeing relatively frequent pauses in transaction throughput up to
> 30s long under heavy parallel workloads. The only thing that seemed strange
> about them was that the xfsaild was active during the pauses, but making no
> progress. It was running exactly 20 times a second (on the 50ms no-progress
> backoff), and the number of pushbuf events was constant across this time as
> well.  IOWs, the xfsaild appeared to be stuck on buffers that it could not 
> push
> out.

. . .

If you like I can take this patch directly (i.e., not wait for you to
send a separate pull request).  It fixes a real bug but since delayed
logging still an experimental feature I am not inclined to send it to
Linus at this point in the cycle.  Let me know if you disagree.

                                        -Alex