이 콘텐츠는 선택한 언어로 제공되지 않습니다.

Chapter 11. Using CPU Manager


11.1. What CPU Manager Does

Important

CPU Manager is a Technology Preview feature. Technology Preview features are not supported with Red Hat production service level agreements (SLAs), might not be functionally complete, and Red Hat does not recommend to use them for production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information on Red Hat Technology Preview features support scope, see https://access.redhat.com/support/offerings/techpreview/.

CPU Manager manages groups of CPUs and constrains workloads to specific CPUs.

CPU Manager is useful for workloads that have some of these attributes:

  • Require as much CPU time as possible.
  • Are sensitive to processor cache misses.
  • Are low-latency network applications.
  • Coordinate with other processes and benefit from sharing a single processor cache.

11.2. Setting up CPU Manager

To set up CPU Manager:

  1. Optionally, label a node:

    # oc label node perf-node.example.com cpumanager=true
  2. Enable CPU manager support on the target node:

    # cat /etc/origin/node/node-config.yaml
    ...
    kubeletArguments:
    ...
      feature-gates:
      - CPUManager=true
      cpu-manager-policy:
      - static
      cpu-manager-reconcile-period:
      - 5s
      kube-reserved: 
    1
    
      - cpu=500m
    
    # systemctl restart atomic-openshift-node
    1
    kube-reserved is a required setting. The value may need to be adjusted depending on your environment.
  3. Create a pod that requests a core or multiple cores. Both limits and requests must have their CPU value set to a whole integer. That is the number of cores that will be dedicated to this pod:

    # cat cpumanager.yaml
    apiVersion: v1
    kind: Pod
    metadata:
      generateName: cpumanager-
    spec:
      containers:
      - name: cpumanager
        image: gcr.io/google_containers/pause-amd64:3.0
        resources:
          requests:
            cpu: 1
            memory: "1G"
          limits:
            cpu: 1
            memory: "1G"
      nodeSelector:
        cpumanager: "true"
  4. Create the pod:

    # oc create -f cpumanager.yaml
  5. Verify that the pod is scheduled to the node that you labeled:

    # oc describe pod cpumanager
    Name:         cpumanager-4gdtn
    Namespace:    test
    Node:         perf-node.example.com/172.31.62.105
    ...
        Limits:
          cpu:     1
          memory:  1G
        Requests:
          cpu:        1
          memory:     1G
    ...
    QoS Class:       Guaranteed
    Node-Selectors:  cpumanager=true
                     region=primary
  6. Verify that the cgroups are set up correctly. Get the PID of the pause process:

    # systemd-cgls -l
    ├─1 /usr/lib/systemd/systemd --system --deserialize 20
    ├─kubepods.slice
    │ ├─kubepods-pod0ec1ab8b_e1c4_11e7_bb22_027b30990a24.slice
    │ │ ├─docker-b24e29bc4021064057f941dc5f3538595c317d294f2c8e448b5e61a29c026d1c.scope
    │ │ │ └─44216 /pause

    Pods of QoS tier Guaranteed are placed within the kubepods.slice. Pods of other QoS tiers end up in child cgroups of kubepods.

    # cd /sys/fs/cgroup/cpuset/kubepods.slice/kubepods-pod0ec1ab8b_e1c4_11e7_bb22_027b30990a24.slice/docker-b24e29bc4021064057f941dc5f3538595c317d294f2c8e448b5e61a29c026d1c.scope
    # for i in `ls cpuset.cpus tasks` ; do echo -n "$i "; cat $i ; done
    cpuset.cpus 2
    tasks 44216
  7. Check the allowed CPU list for the task:

    # grep ^Cpus_allowed_list /proc/44216/status
    Cpus_allowed_list:      2
  8. Verify that another pod (in this case, the pod in the burstable QoS tier) on the system can not run on the core allocated for the Guaranteed pod:

    # cat /sys/fs/cgroup/cpuset/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-podbe76ff22_dead_11e7_b99e_027b30990a24.slice/docker-da621bea7569704fc39f84385a179923309ab9d832f6360cccbff102e73f9557.scope/cpuset.cpus
    0-1,3
    # oc describe node perf-node.example.com
    ...
    Capacity:
     cpu:     4
     memory:  16266720Ki
     pods:    40
    Allocatable:
     cpu:     3500m
     memory:  16164320Ki
     pods:    40
    ---
      Namespace                  Name                      CPU Requests  CPU Limits  Memory Requests  Memory Limits
      ---------                  ----                      ------------  ----------  ---------------  -------------
      test                        cpumanager-4gdtn          1 (28%)       1 (28%)     1G (6%)          1G (6%)
      test                        cpumanager-hczts          1 (28%)       1 (28%)     1G (6%)          1G (6%)
      test                        cpumanager-r9wrq          1 (28%)       1 (28%)     1G (6%)          1G (6%)
    ...
    Allocated resources:
      (Total limits may be over 100 percent, i.e., overcommitted.)
      CPU Requests  CPU Limits  Memory Requests  Memory Limits
      ------------  ----------  ---------------  -------------
      3 (85%)       3 (85%)     5437500k (32%)   9250M (55%)

    This VM has four CPU cores. You set kube-reserved to 500 millicores, meaning half of one core is subtracted from the total capacity of the node to arrive at the Node Allocatable amount.

    You can see that Allocatable CPU is 3500 millicores. This means we can run three of our CPU manager pods since each will take one whole core. A whole core is equivalent to 1000 millicores.

    If you try to schedule a fourth pod, the system will accept the pod, but it will never be scheduled:

    # oc get pods --all-namespaces |grep test
    test              cpumanager-4gdtn               1/1       Running            0          8m
    test              cpumanager-hczts               1/1       Running            0          8m
    test              cpumanager-nb9d5               0/1       Pending            0          8m
    test              cpumanager-r9wrq               1/1       Running            0          8m
Red Hat logoGithubredditYoutubeTwitter

자세한 정보

평가판, 구매 및 판매

커뮤니티

Red Hat 소개

Red Hat은 기업이 핵심 데이터 센터에서 네트워크 에지에 이르기까지 플랫폼과 환경 전반에서 더 쉽게 작업할 수 있도록 강화된 솔루션을 제공합니다.

보다 포괄적 수용을 위한 오픈 소스 용어 교체

Red Hat은 코드, 문서, 웹 속성에서 문제가 있는 언어를 교체하기 위해 최선을 다하고 있습니다. 자세한 내용은 다음을 참조하세요.Red Hat 블로그.

Red Hat 문서 정보

Legal Notice

Theme

© 2026 Red Hat
맨 위로 이동