On Thu, 06 Jan 2011 14:15:37 +0100 Dominik Klein <dk@xxxxxxxxxxxxxxxx> wrote: > Hi > > I am playing with cgroups and try to limit block io for guests. > > The proof of concept is: > > # mkdir /dev/cgroup/blkio > # mount -t cgroup -o blkio blkio /dev/cgroup/blkio/ > # cd blkio/ > # mkdir test > # cd test/ > # ls -l /dev/vdisks/kirk > lrwxrwxrwx 1 root root 7 2011-01-06 13:46 /dev/vdisks/kirk -> ../dm-5 > # ls -l /dev/dm-5 > brw-rw---- 1 root disk 253, 5 2011-01-06 13:36 /dev/dm-5 > # echo "253:5 1048576" > blkio.throttle.write_bps_device > # echo $$ > tasks > # dd if=/dev/zero of=/dev/dm-5 bs=1M count=20 > 20+0 records in > 20+0 records out > 20971520 bytes (21 MB) copied, 20.0223 s, 1.0 MB/s > > So limit applies to the dd child of my shell. > > Now I assign /dev/dm-5 (/dev/vdisks/kirk) to a vm and echo the qemu-kvm > pid into tasks. Limits are not applied, the guest can happily use max io > bandwidth. > qemu consists of several threads. Cgroup works per thread now. Could you double check "all threads for qemu" are in a cgroup ? I think you have to write all thread-ID to "tasks" file when you move qemu after starting it. Thanks, -Kame -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
