6.12-stable review patch. If anyone has any objections, please let me know.
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From: Waiman Long longman@redhat.com
[ Upstream commit 668e041662e92ab3ebcb9eb606d3ec01884546ab ]
Before commit f0af1bfc27b5 ("cgroup/cpuset: Relax constraints to partition & cpus changes"), a cpuset partition cannot be enabled if not all the requested CPUs can be granted from the parent cpuset. After that commit, a cpuset partition can be created even if the requested exclusive CPUs contain CPUs not allowed its parent. The delmask containing exclusive CPUs to be removed from its parent wasn't adjusted accordingly.
That is not a problem until the introduction of a new isolated_cpus mask in commit 11e5f407b64a ("cgroup/cpuset: Keep track of CPUs in isolated partitions") as the CPUs in the delmask may be added directly into isolated_cpus.
As a result, isolated_cpus may incorrectly contain CPUs that are not isolated leading to incorrect data reporting. Fix this by adjusting the delmask to reflect the actual exclusive CPUs for the creation of the partition.
Fixes: 11e5f407b64a ("cgroup/cpuset: Keep track of CPUs in isolated partitions") Signed-off-by: Waiman Long longman@redhat.com Signed-off-by: Tejun Heo tj@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/cgroup/cpuset.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 24ece85fd3b12..f7ad5651c93db 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1656,9 +1656,9 @@ static int update_parent_effective_cpumask(struct cpuset *cs, int cmd, if (nocpu) return PERR_NOCPUS;
- cpumask_copy(tmp->delmask, xcpus); - deleting = true; - subparts_delta++; + deleting = cpumask_and(tmp->delmask, xcpus, parent->effective_xcpus); + if (deleting) + subparts_delta++; new_prs = (cmd == partcmd_enable) ? PRS_ROOT : PRS_ISOLATED; } else if (cmd == partcmd_disable) { /*