On Tue, Apr 14, 2009 at 06:30:22PM +0900, Ryo Tsuruta wrote: > Hi Vivek, > > > I quickly looked at the xls sheet. Most of the test cases seem to be > > direct IO. Have you done testing with buffered writes/async writes and > > been able to provide service differentiation between cgroups? > > > > For example, two "dd" threads running in two cgroups doing writes. > > Thanks for taking a look at the sheet. I did a buffered write test > with "fio." Only two "dd" threads can't generate enough I/O load to > make dm-ioband start bandwidth control. The following is a script that > I actually used for the test. > > #!/bin/bash > sync > echo 1 > /proc/sys/vm/drop_caches > arg="--size=64m --rw=write --numjobs=50 --group_reporting" > echo $$ > /cgroup/1/tasks > fio $arg --name=ioband1 --directory=/mnt1 --output=ioband1.log & > echo $$ > /cgroup/2/tasks > fio $arg --name=ioband2 --directory=/mnt2 --output=ioband2.log & > echo $$ > /cgroup/tasks > wait > Ryo, Can you also send bio-cgroup patches which apply to 2.6.30-rc1 so that I can do testing for async writes. Why have you split the regular patch and bio-cgroup patch? Do you want to address only reads and sync writes? In the above test case, do these "fio" jobs finish at different times? In my testing I see that two dd generate a lot of traffic at IO scheudler level but traffic seems to be bursty. So when higher weight process has done some IO, it seems to disappear for .2 to 1 seconds and in that time other writer gets to do lot of IO and eradicates any service difference provided so far. I am not sure where this high priority writer is blocked and that needs to be looked into. But I am sure that you will also face the same issue. Thanks Vivek > I created two dm-devices to easily monitor the throughput of each > cgroup by iostat, and gave weights of 200 for cgroup1 and 100 for > cgroup2 that means cgroup1 can use twice bandwidth of cgroup2. The > following is a part of the output of iostat. dm-0 and dm-1 corresponds > to ioband1 and ioband2. You can see the bandwidth is according to the > weights. > > avg-cpu: %user %nice %system %iowait %steal %idle > 0.99 0.00 6.44 92.57 0.00 0.00 > > Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn > dm-0 3549.00 0.00 28392.00 0 28392 > dm-1 1797.00 0.00 14376.00 0 14376 > > avg-cpu: %user %nice %system %iowait %steal %idle > 1.01 0.00 4.02 94.97 0.00 0.00 > > Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn > dm-0 3919.00 0.00 31352.00 0 31352 > dm-1 1925.00 0.00 15400.00 0 15400 > > avg-cpu: %user %nice %system %iowait %steal %idle > 0.00 0.00 5.97 94.03 0.00 0.00 > > Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn > dm-0 3534.00 0.00 28272.00 0 28272 > dm-1 1773.00 0.00 14184.00 0 14184 > > avg-cpu: %user %nice %system %iowait %steal %idle > 0.50 0.00 6.00 93.50 0.00 0.00 > > Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn > dm-0 4053.00 0.00 32424.00 0 32424 > dm-1 2039.00 8.00 16304.00 8 16304 > > Thanks, > Ryo Tsuruta -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
