Re: [PATCH] cgroup/cpuset: Prevent leakage of isolated CPUs into sched domains

[Tejun Heo]

On Thu, Dec 05, 2024 at 02:51:01PM -0500, Waiman Long wrote:
> Isolated CPUs are not allowed to be used in a non-isolated partition.
> The only exception is the top cpuset which is allowed to contain boot
> time isolated CPUs.
> 
> Commit ccac8e8de99c ("cgroup/cpuset: Fix remote root partition creation
> problem") introduces a simplified scheme of including only partition
> roots in sched domain generation. However, it does not properly account
> for this exception case. This can result in leakage of isolated CPUs
> into a sched domain.
> 
> Fix it by making sure that isolated CPUs are excluded from the top
> cpuset before generating sched domains.
> 
> Also update the way the boot time isolated CPUs are handled in
> test_cpuset_prs.sh to make sure that those isolated CPUs are really
> isolated instead of just skipping them in the tests.
> 
> Fixes: ccac8e8de99c ("cgroup/cpuset: Fix remote root partition creation problem")
> Signed-off-by: Waiman Long <longman@xxxxxxxxxx>

Applied to cgroup/for-6.13-fixes.

Thanks.

-- 
tejun