Manage HugePages

    FEATURE STATE:

    1. Kubernetes nodes must pre-allocate huge pages in order for the node to report its huge page capacity. A node can pre-allocate huge pages for multiple sizes.

    The nodes will automatically discover and report all huge page resources as schedulable resources.

    API

    A pod may consume multiple huge page sizes in a single pod spec. In this case it must use medium: HugePages-<hugepagesize> notation for all volume mounts.

    1. apiVersion: v1
    2. kind: Pod
    3. metadata:
    4.   name: huge-pages-example
    5. spec:
    7.   - name: example
    8.     command:
    9.     - sleep
    10.     - inf
    11.     volumeMounts:
    12.     - mountPath: /hugepages
    13.       name: hugepage
    14.     resources:
    15.       limits:
    16.         hugepages-2Mi: 100Mi
    18.         memory: 100Mi
    19.   volumes:
    20.   - name: hugepage
    21.     emptyDir:
    22.       medium: HugePages
    • Huge page requests must equal the limits. This is the default if limits are specified, but requests are not.
    • Huge pages are isolated at a container scope, so each container has own limit on their cgroup sandbox as requested in a container spec.
    • EmptyDir volumes backed by huge pages may not consume more huge page memory than the pod request.
    • Applications that consume huge pages via shmget() with SHM_HUGETLB must run with a supplemental group that matches proc/sys/vm/hugetlb_shm_group.
    • Huge page usage in a namespace is controllable via ResourceQuota similar to other compute resources like cpu or memory using the token.