On Fri, Jun 05, 2009 at 11:14:38PM +0200, Jan Kara wrote: > On Fri 05-06-09 21:15:28, Jens Axboe wrote: > > On Fri, Jun 05 2009, Frederic Weisbecker wrote: > > > The result with noop is even more impressive. > > > > > > See: http://kernel.org/pub/linux/kernel/people/frederic/dbench-noop.pdf > > > > > > Also a comparison, noop with pdflush against noop with bdi writeback: > > > > > > http://kernel.org/pub/linux/kernel/people/frederic/dbench-noop-cmp.pdf > > > > OK, so things aren't exactly peachy here to begin with. It may not > > actually BE an issue, or at least now a new one, but that doesn't mean > > that we should not attempt to quantify the impact. > What looks interesting is also the overall throughput. With pdflush we > get to 2.5 MB/s + 26 MB/s while with per-bdi we get to 2.7 MB/s + 13 MB/s. > So per-bdi seems to be *more* fair but throughput suffers a lot (which > might be inevitable due to incurred seeks). Heh indeed, I was confused with the colors here but yes pdflush has a faster total and a higher unfairness with noop, at least with this test. > Frederic, how much does dbench achieve for you just on one partition > (test both consecutively if possible) with as many threads as have those > two dbench instances together? Thanks. Good idea, I'll try it out so that there wouldn't have any per superblock ordering there, or whathever that could be. Thanks. > Honza > -- > Jan Kara <jack@xxxxxxx> > SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
