Re: [PATCH-cgroup v2] cgroup/cpuset: Include isolated cpuset CPUs in cpu_is_isolated() check

Tejun Heo
2023-12-06T19:38:21Z

On Tue, Dec 05, 2023 at 05:21:14PM -0500, Waiman Long wrote:
> Currently, the cpu_is_isolated() function checks only the statically
> isolated CPUs specified via the "isolcpus" and "nohz_full" kernel
> command line options. This function is used by vmstat and memcg to
> reduce interference with isolated CPUs by not doing stat flushing
> or scheduling works on those CPUs.
>
> Workloads running on isolated CPUs within isolated cpuset
> partitions should receive the same treatment to reduce unnecessary
> interference. This patch introduces a new cpuset_cpu_is_isolated()
> function to be called by cpu_is_isolated() so that the set of dynamically
> created cpuset isolated CPUs will be included in the check.
>
> Assuming that testing a bit in a cpumask is atomic, no synchronization
> primitive is currently used to synchronize access to the cpuset's
> isolated_cpus mask.
>
> Signed-off-by: Waiman Long <longman@redhat.com>

Applied to cgroup/for-6.8.

Thanks.

--
tejun