Vivek Goyal <vgoyal@xxxxxxxxxx> writes: > 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? O_DIRECT bypasses the page cache, and hence the readahead code. Try driving deeper queue depths and/or using larger I/O sizes. Cheers, Jeff _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
