From 4ab45e5c9351c468f297da3b27f13004b563312b Mon Sep 17 00:00:00 2001 From: yaoyinnan Date: Fri, 8 Jul 2022 19:36:06 +0800 Subject: [PATCH] docs: Update support for host cgroupv2 Currently cgroup v2 is supported. Remove the note that host cgroup v2 is not supported. Fixes: #3073 Signed-off-by: yaoyinnan --- docs/design/host-cgroups.md | 19 ++++++++----------- .../containerd/containerd-install.md | 6 ------ 2 files changed, 8 insertions(+), 17 deletions(-) diff --git a/docs/design/host-cgroups.md b/docs/design/host-cgroups.md index de5f3288d..0049ba5ab 100644 --- a/docs/design/host-cgroups.md +++ b/docs/design/host-cgroups.md @@ -12,7 +12,7 @@ The OCI [runtime specification][linux-config] provides guidance on where the con > [`cgroupsPath`][cgroupspath]: (string, OPTIONAL) path to the cgroups. It can be used to either control the cgroups > hierarchy for containers or to run a new process in an existing container -Cgroups are hierarchical, and this can be seen with the following pod example: +The cgroups are hierarchical, and this can be seen with the following pod example: - Pod 1: `cgroupsPath=/kubepods/pod1` - Container 1: `cgroupsPath=/kubepods/pod1/container1` @@ -247,14 +247,14 @@ cgroup size and constraints accordingly. # Supported cgroups -Kata Containers currently only supports cgroups `v1`. +Kata Containers currently supports cgroups `v1` and `v2`. In the following sections each cgroup is described briefly. -## Cgroups V1 +## cgroups v1 -`Cgroups V1` are under a [`tmpfs`][1] filesystem mounted at `/sys/fs/cgroup`, where each cgroup is -mounted under a separate cgroup filesystem. A `Cgroups v1` hierarchy may look like the following +`cgroups v1` are under a [`tmpfs`][1] filesystem mounted at `/sys/fs/cgroup`, where each cgroup is +mounted under a separate cgroup filesystem. A `cgroups v1` hierarchy may look like the following diagram: ``` @@ -301,13 +301,12 @@ diagram: A process can join a cgroup by writing its process id (`pid`) to `cgroup.procs` file, or join a cgroup partially by writing the task (thread) id (`tid`) to the `tasks` file. -Kata Containers only supports `v1`. To know more about `cgroups v1`, see [cgroupsv1(7)][2]. -## Cgroups V2 +## cgroups v2 -`Cgroups v2` are also known as unified cgroups, unlike `cgroups v1`, the cgroups are -mounted under the same cgroup filesystem. A `Cgroups v2` hierarchy may look like the following +`cgroups v2` are also known as unified cgroups, unlike `cgroups v1`, the cgroups are +mounted under the same cgroup filesystem. A `cgroups v2` hierarchy may look like the following diagram: ``` @@ -354,8 +353,6 @@ Same as `cgroups v1`, a process can join the cgroup by writing its process id (` `cgroup.procs` file, or join a cgroup partially by writing the task (thread) id (`tid`) to `cgroup.threads` file. -Kata Containers does not support cgroups `v2` on the host. - ### Distro Support Many Linux distributions do not yet support `cgroups v2`, as it is quite a recent addition. diff --git a/docs/install/container-manager/containerd/containerd-install.md b/docs/install/container-manager/containerd/containerd-install.md index 15e1e332e..2be3192d9 100644 --- a/docs/install/container-manager/containerd/containerd-install.md +++ b/docs/install/container-manager/containerd/containerd-install.md @@ -19,12 +19,6 @@ > - If you decide to proceed and install a Kata Containers release, you can > still check for the latest version of Kata Containers by running > `kata-runtime check --only-list-releases`. -> -> - These instructions will not work for Fedora 31 and higher since those -> distribution versions only support cgroups version 2 by default. However, -> Kata Containers currently requires cgroups version 1 (on the host side). See -> https://github.com/kata-containers/kata-containers/issues/927 for further -> details. ## Install Kata Containers