On Mon, Jun 22, 2009 at 11:40:42AM -0400, Jeff Moyer wrote: > Vivek Goyal <vgoyal@xxxxxxxxxx> writes: > > > On Sun, Jun 21, 2009 at 08:51:16PM +0530, Balbir Singh wrote: > >> * Vivek Goyal <vgoyal@xxxxxxxxxx> [2009-06-19 16:37:18]: > >> > >> > > >> > Hi All, > >> > > >> > Here is the V5 of the IO controller patches generated on top of 2.6.30. > >> [snip] > >> > >> > Testing > >> > ======= > >> > > >> > >> [snip] > >> > >> I've not been reading through the discussions in complete detail, but > >> I see no reference to async reads or aio. In the case of aio, aio > >> presumes the context of the user space process. Could you elaborate on > >> any testing you've done with these cases? > >> > > > > Hi Balbir, > > > > So far I had not done any testing with AIO. I have done some just now. > > Here are the results. > > > > Test1 (AIO reads) > > ================ > > Set up two fio, AIO read jobs in two cgroup with weight 1000 and 500 > > respectively. I am using cfq scheduler. Following are some lines from my test > > script. > > > > =================================================================== > > fio_args="--ioengine=libaio --rw=read --size=512M" > > AIO doesn't make sense without O_DIRECT. > Ok, here are the read results with --direct=1 for reads. In previous posting, writes were already direct. test1 statistics: time=8 16 20796 sectors=8 16 1049648 test2 statistics: time=8 16 10551 sectors=8 16 581160 Not sure why reads are so slow with --direct=1? In the previous test (no direct IO), I had cleared the caches using (echo 3 > /proc/sys/vm/drop_caches) so reads could not have come from page cache? Thanks Vivek -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
