runc update will clear cpu burst value

[lifubang]

1. runc update will clear cpu burst value

root@acmcoder:/home/acmcoder/ubuntutest# cat /sys/fs/cgroup/cpu/user.slice/test/cpu.cfs_burst_us
0
root@acmcoder:/home/acmcoder/ubuntutest#
root@acmcoder:/home/acmcoder/ubuntutest# runc update --cpu-burst=10000 test
root@acmcoder:/home/acmcoder/ubuntutest# cat /sys/fs/cgroup/cpu/user.slice/test/cpu.cfs_burst_us
10000
root@acmcoder:/home/acmcoder/ubuntutest# runc update --memory=100M test
root@acmcoder:/home/acmcoder/ubuntutest# cat /sys/fs/cgroup/cpu/user.slice/test/cpu.cfs_burst_us
0

2. Error for container update for the kernel not support cpu burst
   When I'm testing tests/int: swap-related fixes #4188 in ubuntu 20.04 with cgroupv2, I got some errors:

✗ update cgroup v1/v2 common limits
   (in test file tests/integration/update.bats, line 74)
     `[ "$status" -eq 0 ]' failed
   runc spec (status=0):

   runc run -d --console-socket /tmp/bats-run-JaQGX1/runc.L3uZyo/tty/sock test_update (status=0):

   cat: /sys/fs/cgroup/runc-cgroups-integration-test/test-cgroup-16459/memory.swap.max: No such file or directory
   current 33554432 !? 33554432
   current 25165824 !? 25165824
   current 20 !? 20
   runc update test_update --cpuset-cpus 1 (status=1):
   time="2024-03-03T07:53:10+08:00" level=warning msg="Setting back cgroup configs failed due to error: open /sys/fs/cgroup/runc-cgroups-integration-test/test-cgroup-16459/cpu.max.burst: no such file or directory, your state.json and actual configs might be inconsistent."
   time="2024-03-03T07:53:10+08:00" level=error msg="open /sys/fs/cgroup/runc-cgroups-integration-test/test-cgroup-16459/cpu.max.burst: no such file or directory"

root@iZj6ccy7ct4rpjdodcohzlZ:~/ubuntu# uname -a
Linux iZj6ccy7ct4rpjdodcohzlZ 5.4.0-170-generic #188-Ubuntu SMP Wed Jan 10 09:51:01 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux
root@iZj6ccy7ct4rpjdodcohzlZ:~/ubuntu# ls /sys/fs/cgroup/user.slice/user-0.slice/
cgroup.controllers      cpu.max                cpu.weight           memory.low        rdma.max
cgroup.events           cpu.pressure           cpu.weight.nice      memory.max        session-104.scope
cgroup.freeze           cpuset.cpus            io.max               memory.min        session-106.scope
cgroup.max.depth        cpuset.cpus.effective  io.pressure          memory.oom.group  session-109.scope
cgroup.max.descendants  cpuset.cpus.partition  io.stat              memory.pressure   test
cgroup.procs            cpuset.mems            io.weight            memory.stat       test1
cgroup.stat             cpuset.mems.effective  memory.current       pids.current      user@0.service
cgroup.subtree_control  cpu.stat               memory.events        pids.events       user-runtime-dir@0.service
cgroup.threads          cpu.uclamp.max         memory.events.local  pids.max
cgroup.type             cpu.uclamp.min         memory.high          rdma.current

[lifubang]

I'll add a testcase for this issue later.

[rata]

The ubuntu issue you mention seems the same that breaks containerd tests with the new runc: https://github.com/containerd/containerd/actions/runs/8540558806/job/23398018642?pr=9313:

=== FAIL: integration/client TestTaskUpdate (0.23s)
    log_hook.go:47: time="2024-04-03T14:43:18.318748080Z" level=debug msg="remote introspection plugin filters" func="proxy.(*introspectionRemote).Plugins" file="/home/runner/actions-runner/_work/containerd/containerd/core/introspection/proxy/remote.go:57" filters="[type==io.containerd.snapshotter.v1, id==overlayfs]" testcase=TestTaskUpdate
    container_linux_test.go:137: runc did not terminate successfully: exit status 1: openat2 /sys/fs/cgroup/testing/TestTaskUpdate/cpu.max.burst: no such file or directory
        : unknown

@lifubang do you know already what the fix should/might look like? Or did you find a wall as @kolyshkin with his PR?

[lifubang]

Yes, it’s easy to fix this issue, but we found some other issues for ‘runc update’, we want to fix all of these issues in one PR, but it’s too difficult, I think maybe we should fix them step by step.