Uploaded image for project: 'OpenShift Virtualization'
  1. OpenShift Virtualization
  2. CNV-63585

[Tracker Bug] VMI pod slowness due to CPU throttling with k8s 1.33

XMLWordPrintable

    • Icon: Bug Bug
    • Resolution: Unresolved
    • Icon: Blocker Blocker
    • CNV v4.20.0
    • None
    • CNV Virt-Node
    • None
    • Quality / Stability / Reliability
    • 0.42
    • False
    • Hide

      None

      Show
      None
    • False
    • None
    • Critical
    • None

      Description of problem:

      When starting a vmi with guaranteed QOS, the resulting virt-launcher pod is very slow. After some analysis, it shows that the cgroups are configured as the following: 
      ```
      /<path-to-pod>/<our-container>/cpu.max (1000 100000)
      /<path-to-pod>/<our-container>/container/cpu.max (max 100000)
      ```
      Which means that the cpu is throttled.
      
      The same pod with 4.19 the cgroups:
      ```
      /<path-to-pod>/<our-container>/cpu.max (200000 100000)
      /<path-to-pod>/<our-container>/container/cpu.max (200000 100000)
      ```

      Version-Release number of selected component (if applicable):

      4.20

      How reproducible:

      Everytime

      Steps to Reproduce:

      1. Start a vm qith dedicated cpu
      2. Look at the cgroups in the node where the pod has been scheduled
      3. Try to console the vmi 

      Actual results:

      The vmi is booting very very slow

      Expected results:

      The vmi booting at normal speed

      Additional info:

      U/S cri-o issue: https://github.com/cri-o/cri-o/issues/9251
      
      
      We also noticed a general slowness in the runtime of the CI with provider 1.33. In particular, with 1.32 provider the testsuite takes ~1h30m; against the 4h20m with provider 1.33.
      My personal suspect is that, even with non guuaranteed QOS, there is something wrong. 

              sgott@redhat.com Stuart Gott
              ffossemo@redhat.com Federico Fossemo
              Denys Shchedrivyi Denys Shchedrivyi
              Votes:
              0 Vote for this issue
              Watchers:
              7 Start watching this issue

                Created:
                Updated: