Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.16 kernel[0].
If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'. If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'. Once testing of the upstream kernel is complete, please mark this bug as "Confirmed". Thanks in advance. [0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.16 ** Changed in: linux (Ubuntu) Importance: Undecided => Medium ** Tags added: kernel-da-key xenial ** Changed in: linux (Ubuntu) Status: Confirmed => Incomplete -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1760375 Title: cgroup blkio throttle does not work on root group Status in linux package in Ubuntu: Incomplete Bug description: from kernel document, https://www.kernel.org/doc/Documentation/cgroup-v1/blkio-controller.txt ``` Throttling/Upper Limit policy ----------------------------- - Enable Block IO controller CONFIG_BLK_CGROUP=y - Enable throttling in block layer CONFIG_BLK_DEV_THROTTLING=y - Mount blkio controller (see cgroups.txt, Why are cgroups needed?) mount -t cgroup -o blkio none /sys/fs/cgroup/blkio - Specify a bandwidth rate on particular device for root group. The format for policy is "<major>:<minor> <bytes_per_second>". echo "8:16 1048576" > /sys/fs/cgroup/blkio/blkio.throttle.read_bps_device Above will put a limit of 1MB/second on reads happening for root group on device having major/minor number 8:16. - Run dd to read a file and see if rate is throttled to 1MB/s or not. # dd iflag=direct if=/mnt/common/zerofile of=/dev/null bs=4K count=1024 1024+0 records in 1024+0 records out 4194304 bytes (4.2 MB) copied, 4.0001 s, 1.0 MB/s Limits for writes can be put using blkio.throttle.write_bps_device file. ``` tested with ubuntu 16.04(xenial) and seems throttle not working, but on my virtual machine, ubuntu 14.04(trusty) works. ``` ubuntu16.04(xenial) root@i-x3mn8m8i:~# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT vda 253:0 0 20G 0 disk `-vda1 253:1 0 20G 0 part / vdb 253:16 0 1G 0 disk [SWAP] root@i-x3mn8m8i:~# dd if=/dev/zero of=test.img bs=4k oflag=direct ^C16246+0 records in 16246+0 records out 66543616 bytes (67 MB, 63 MiB) copied, 3.15081 s, 21.1 MB/s root@i-x3mn8m8i:~# echo 253:0 1000 > /sys/fs/cgroup/blkio/blkio.throttle.write_iops_device root@i-x3mn8m8i:~# dd if=/dev/zero of=test.img bs=4k oflag=direct ^C26702+0 records in 26702+0 records out 109371392 bytes (109 MB, 104 MiB) copied, 5.2413 s, 20.9 MB/s ubuntu14.04(trusty) root@i-ulhx27oo:~# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT vda 253:0 0 20G 0 disk `-vda1 253:1 0 20G 0 part / vdb 253:16 0 1G 0 disk [SWAP] root@i-ulhx27oo:~# dd if=/dev/zero of=test.img bs=4k oflag=direct ^C27679+0 records in 27679+0 records out 113373184 bytes (113 MB) copied, 5.43766 s, 20.8 MB/s root@i-ulhx27oo:~# echo 253:0 1000 > /sys/fs/cgroup/blkio/blkio.throttle.write_iops_device root@i-ulhx27oo:~# dd if=/dev/zero of=test.img bs=4k oflag=direct ^C7553+0 records in 7553+0 records out 30937088 bytes (31 MB) copied, 7.60268 s, 4.1 MB/s ``` To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1760375/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
