Re: Time sliced CFQ io scheduler

Jens Axboe
2004-12-08T10:09:39Z

On Wed, Dec 08 2004, Jens Axboe wrote:
> On Wed, Dec 08 2004, Jens Axboe wrote:
> > > Hmm, damn. Lots of stuff. I guess some of the notable ones that I've
> > > had trouble with are OraSim (Oracle might give you a copy), Andrew's
> > > patch scripts when applying a stack of patches, pgbench... can't
> > > really remember any others off the top of my head.
> >
> > The patch scripts case is interesting, last night (when committing other
> > patches) I was thinking I should try and bench that today. It has a good
> > mix of reads and writes.
>
> AS is currently 10 seconds faster for that workload (untar of a kernel
> and then applying 2237 patches). AS completes it in 155 seconds, CFQ
> takes 164 seconds.

DEADLINE does 160 seconds, btw.

Something like

for i in patches.*/*; do cp "$i" /dev/null; done

while running a

dd if=/dev/zero of=testfile bs=64k

could be better for both schedulers. AS completes the workload in
4min 14sec, CFQ in 3min 5sec. I don't have the time to try DEADLINE :-)

--
Jens Axboe