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 <yaoyinnan@foxmail.com>
This commit is contained in:
yaoyinnan 2022-07-08 19:36:06 +08:00
parent 9dfd949f23
commit 4ab45e5c93
2 changed files with 8 additions and 17 deletions

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@ -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.

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@ -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