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| author | Waiman Long <longman@redhat.com> | 2026-01-12 19:00:19 +0300 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2026-03-04 15:19:56 +0300 |
| commit | efa59cc2142db0df3098043bc48efe14edbd5c90 (patch) | |
| tree | fc112b4036bd4715032018d40f9c7b2e161988d4 /Documentation | |
| parent | b725955d651dfb8f4e68feadc7b9cde09537e57a (diff) | |
| download | linux-efa59cc2142db0df3098043bc48efe14edbd5c90.tar.xz | |
cgroup/cpuset: Don't fail cpuset.cpus change in v2
[ Upstream commit 6e6f13f6d5095f3a432da421e78f4d7d51ef39c8 ]
Commit fe8cd2736e75 ("cgroup/cpuset: Delay setting of CS_CPU_EXCLUSIVE
until valid partition") introduced a new check to disallow the setting
of a new cpuset.cpus.exclusive value that is a superset of a sibling's
cpuset.cpus value so that there will at least be one CPU left in the
sibling in case the cpuset becomes a valid partition root. This new
check does have the side effect of failing a cpuset.cpus change that
make it a subset of a sibling's cpuset.cpus.exclusive value.
With v2, users are supposed to be allowed to set whatever value they
want in cpuset.cpus without failure. To maintain this rule, the check
is now restricted to only when cpuset.cpus.exclusive is being changed
not when cpuset.cpus is changed.
The cgroup-v2.rst doc file is also updated to reflect this change.
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/admin-guide/cgroup-v2.rst | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 0e6c67ac585a..edcd125d6992 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -2538,10 +2538,10 @@ Cpuset Interface Files Users can manually set it to a value that is different from "cpuset.cpus". One constraint in setting it is that the list of CPUs must be exclusive with respect to "cpuset.cpus.exclusive" - of its sibling. If "cpuset.cpus.exclusive" of a sibling cgroup - isn't set, its "cpuset.cpus" value, if set, cannot be a subset - of it to leave at least one CPU available when the exclusive - CPUs are taken away. + and "cpuset.cpus.exclusive.effective" of its siblings. Another + constraint is that it cannot be a superset of "cpuset.cpus" + of its sibling in order to leave at least one CPU available to + that sibling when the exclusive CPUs are taken away. For a parent cgroup, any one of its exclusive CPUs can only be distributed to at most one of its child cgroups. Having an |