KEP: Memory Manager Hugepages Availability Verification

[srikalyan]

Summary

This KEP proposes enhancing the Memory Manager's Static policy to verify OS-reported free hugepages availability during pod admission.

Problem

The Memory Manager only tracks hugepage allocations for Guaranteed QoS pods. Burstable/BestEffort pods can consume hugepages (via hugetlbfs mounts or mmap with MAP_HUGETLB) without being tracked, causing subsequent Guaranteed pods to be admitted but fail at runtime when hugepages are exhausted.

Solution

1. cadvisor: Add FreePages field to HugePagesInfo (PR: Add FreePages to HugePagesInfo for hugepage availability reporting google/cadvisor#3804)
2. Memory Manager: Verify OS-reported free hugepages during Allocate() in Static policy
3. Admission: Reject pods when insufficient free hugepages are available

Related

• Issue: Static Memory Manager doesn't verify OS reported available huge pages during pod admission kubernetes#134395
• cadvisor PR: Add FreePages to HugePagesInfo for hugepage availability reporting google/cadvisor#3804

KEP Metadata

• SIG: sig-node
• Stage: Alpha (target v1.33)
• Feature Gate: MemoryManagerHugepagesVerification

/sig node
/kind kep

[k8s-ci-robot]

@srikalyan: The label(s) area/kubelet cannot be applied, because the repository doesn't have them.

Details

In response to this:

Summary

This KEP proposes enhancing the Memory Manager's Static policy to verify OS-reported free hugepages availability during pod admission.

Problem

The Memory Manager only tracks hugepage allocations for Guaranteed QoS pods. Burstable/BestEffort pods can consume hugepages (via hugetlbfs mounts or mmap with MAP_HUGETLB) without being tracked, causing subsequent Guaranteed pods to be admitted but fail at runtime when hugepages are exhausted.

Solution

1. cadvisor: Add FreePages field to HugePagesInfo (PR: Add FreePages to HugePagesInfo for hugepage availability reporting google/cadvisor#3804)
2. Memory Manager: Verify OS-reported free hugepages during Allocate() in Static policy
3. Admission: Reject pods when insufficient free hugepages are available

Related

• Issue: Static Memory Manager doesn't verify OS reported available huge pages during pod admission kubernetes#134395
• cadvisor PR: Add FreePages to HugePagesInfo for hugepage availability reporting google/cadvisor#3804

KEP Metadata

• SIG: sig-node
• Stage: Alpha (target v1.33)
• Feature Gate: MemoryManagerHugepagesVerification

/sig node
/kind kep
/area kubelet

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[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: srikalyan
Once this PR has been reviewed and has the lgtm label, please assign dchen1107 for approval. For more information see the Code Review Process.

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Details

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• keps/sig-node/OWNERS

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[k8s-ci-robot]

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[k8s-ci-robot]

Hi @srikalyan. Thanks for your PR.

I'm waiting for a github.com member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[srikalyan]

/remove-area kubelet

[k8s-ci-robot]

@srikalyan: Those labels are not set on the issue: area/kubelet

Details

In response to this:

/remove-area kubelet

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.