Re: [PATCH v11 7/8] cgroup/cpuset: Update description of cpuset.cpus.partition in cgroup-v2.rst

[Waiman Long]

On 6/13/22 09:18, Waiman Long wrote:
> On 6/12/22 23:12, Tejun Heo wrote:
> > Hello,
> >
> > On Sun, Jun 12, 2022 at 11:02:38PM -0400, Waiman Long wrote:
> > > That is the behavior enforced by setting the CPU_EXCLUSIVE bit in 
> > > cgroup v1.
> > > I haven't explicitly change it to make it different in cgroup v2. 
> > > The major
> > > reason is that I don't want change to one cpuset to affect a sibling
> > > partition as it may make the code more complicate to validate if a 
> > > partition
> > > is valid.
> > If at all possible, I'd really like to avoid situations where a 
> > parent can't
> > withdraw resources due to something that a descendant does.
>
> No, it doesn't affect parent at all. It just limit whats the siblings 
> can do due to their mutual constraint. If this is what the confusion 
> is about, I will try to reword the doc text.

I am planning to make the following change to the documentation patch. 
Please let me know if that can clarify the confusion, if any.

Thanks,
Longman

diff --git a/Documentation/admin-guide/cgroup-v2.rst 
b/Documentation/admin-guid>
index 9184a09e0fc9..9cbfa25dab97 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -2176,7 +2175,8 @@ Cpuset Interface Files

        For a valid partition root or an invalid partition root with
        the exclusivity rule enabled, changes made to "cpuset.cpus"
-       that violate the exclusivity rule will not be allowed.
+       that violate the exclusivity rule with its siblings will not
+       be allowed.

        A valid non-root parent partition may distribute out all its CPUs
        to its child partitions when there is no task associated with it.