docs: cgroup-v1: Document the cpuset_v2_mode mount option

The cpuset in cgroup v1 accepts a special "cpuset_v2_mode" mount
option that make cpuset.cpus and cpuset.mems behave more like those in
cgroup v2.  Document it to make other people more aware of this feature
that can be useful in some circumstances.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Waiman Long
2020-03-30 10:06:15 -04:00
committed by Tejun Heo
parent 2b729fe7f3
commit 0c05b9bdbf
2 changed files with 17 additions and 2 deletions

View File

@@ -358,8 +358,12 @@ static DECLARE_WORK(cpuset_hotplug_work, cpuset_hotplug_workfn);
static DECLARE_WAIT_QUEUE_HEAD(cpuset_attach_wq);
/*
* Cgroup v2 behavior is used when on default hierarchy or the
* cgroup_v2_mode flag is set.
* Cgroup v2 behavior is used on the "cpus" and "mems" control files when
* on default hierarchy or when the cpuset_v2_mode flag is set by mounting
* the v1 cpuset cgroup filesystem with the "cpuset_v2_mode" mount option.
* With v2 behavior, "cpus" and "mems" are always what the users have
* requested and won't be changed by hotplug events. Only the effective
* cpus or mems will be affected.
*/
static inline bool is_in_v2_mode(void)
{