XFS write speed down

[Dave Chinner]

On Thu, Apr 29, 2010 at 11:46:33PM +0200, Jan Engelhardt wrote:
> Hi,
> 
> Running 2.6.33.2, I am observing this 
> 
> used-xfs$ time ( tar -xf /dev/shm/linux-2.6.33.3.tar ; sync )
> real    12m29.272s
> user    0m0.196s
> sys     0m3.028s

What was the last kernel you ran that didn't have this slowdown?
I see the same test on 2.6.32 to my 2.6TB RAID6 volume take
about 35s.

Can you post the output of "echo w > /proc/sysrq-trigger" while
your test is running?

Cheers,

Dave.

-- 
Dave Chinner
david at fromorbit.com