128 lines
4.2 KiB
Markdown
128 lines
4.2 KiB
Markdown
---
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reviewers:
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- derekwaynecarr
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title: 管理巨页（HugePages）
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content_type: task
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---
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<!--
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---
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reviewers:
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- derekwaynecarr
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title: Manage HugePages
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content_type: task
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---
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--->
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<!-- overview -->
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{{< feature-state state="stable" >}}
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<!--
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Kubernetes supports the allocation and consumption of pre-allocated huge pages
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by applications in a Pod as a **GA** feature. This page describes how users
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can consume huge pages and the current limitations.
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--->
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作为 **GA** 特性，Kubernetes 支持在 Pod 应用中使用预先分配的巨页。本文描述了用户如何使用巨页，以及当前的限制。
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## {{% heading "prerequisites" %}}
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<!--
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1. Kubernetes nodes must pre-allocate huge pages in order for the node to report
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its huge page capacity. A node may only pre-allocate huge pages for a single
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size.
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The nodes will automatically discover and report all huge page resources as a
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schedulable resource.
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--->
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1. 为了使节点能够上报巨页容量，Kubernetes 节点必须预先分配巨页。每个节点只能预先分配一种特定规格的巨页。
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节点会自动发现全部巨页资源，并作为可供调度的资源进行上报。
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<!-- steps -->
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## API
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<!--
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Huge pages can be consumed via container level resource requirements using the
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resource name `hugepages-<size>`, where size is the most compact binary notation
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using integer values supported on a particular node. For example, if a node
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supports 2048KiB page sizes, it will expose a schedulable resource
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`hugepages-2Mi`. Unlike CPU or memory, huge pages do not support overcommit. Note
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that when requesting hugepage resources, either memory or CPU resources must
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be requested as well.
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--->
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用户可以通过在容器级别的资源需求中使用资源名称 `hugepages-<size>` 来使用巨页，其中的 size 是特定节点上支持的以整数值表示的最小二进制单位。 例如，如果节点支持 2048KiB 的页面规格， 它将暴露可供调度的资源 `hugepages-2Mi`。 与 CPU 或内存不同，巨页不支持过量使用（overcommit）。
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注意，在请求巨页资源时，还必须请求内存或 CPU 资源。
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```yaml
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apiVersion: v1
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kind: Pod
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metadata:
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generateName: hugepages-volume-
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spec:
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containers:
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- image: fedora:latest
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command:
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- sleep
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- inf
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name: example
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volumeMounts:
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- mountPath: /hugepages
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name: hugepage
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resources:
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limits:
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hugepages-2Mi: 100Mi
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memory: 100Mi
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requests:
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memory: 100Mi
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volumes:
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- name: hugepage
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emptyDir:
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medium: HugePages
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```
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<!--
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- Huge page requests must equal the limits. This is the default if limits are
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specified, but requests are not.
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- Huge pages are isolated at a pod scope, container isolation is planned in a
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future iteration.
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- EmptyDir volumes backed by huge pages may not consume more huge page memory
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than the pod request.
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- Applications that consume huge pages via `shmget()` with `SHM_HUGETLB` must
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run with a supplemental group that matches `proc/sys/vm/hugetlb_shm_group`.
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- Huge page usage in a namespace is controllable via ResourceQuota similar
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to other compute resources like `cpu` or `memory` using the `hugepages-<size>`
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token.
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--->
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- 巨页的资源请求值必须等于其限制值。该条件在指定了资源限制，而没有指定请求的情况下默认成立。
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- 巨页是被隔离在 pod 作用域的，计划在将来的迭代中实现容器级别的隔离。
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- 巨页可用于 EmptyDir 卷，不过 EmptyDir 卷所使用的巨页数量不能够超出 Pod 请求的巨页数量。
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- 通过带有 `SHM_HUGETLB` 的 `shmget()` 使用巨页的应用，必须运行在一个与
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`proc/sys/vm/hugetlb_shm_group` 匹配的补充组下。
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- 通过 ResourceQuota 资源，可以使用 `hugepages-<size>` 标记控制每个命名空间下的巨页使用量，
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类似于使用 `cpu` 或 `memory` 来控制其他计算资源。
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<!--
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## Future
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- Support container isolation of huge pages in addition to pod isolation.
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- NUMA locality guarantees as a feature of quality of service.
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- LimitRange support.
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--->
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## 待实现的特性
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- 在 pod 级别隔离的基础上，支持巨页在容器级别的隔离。
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- 作为服务质量特性，保证巨页的 NUMA 局部性。
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- 支持 LimitRange 。
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