Re: [PATCH] cgroup/cpuset: Avoid memory migration when nodemasks match

[Tejun Heo]

On Wed, Aug 25, 2021 at 12:54:15PM +0200, Nicolas Saenz Julienne wrote:
> With the introduction of ee9707e8593d ("cgroup/cpuset: Enable memory
> migration for cpuset v2") attaching a process to a different cgroup will
> trigger a memory migration regardless of whether it's really needed.
> Memory migration is an expensive operation, so bypass it if the
> nodemasks passed to cpuset_migrate_mm() are equal.
> 
> Note that we're not only avoiding the migration work itself, but also a
> call to lru_cache_disable(), which triggers and flushes an LRU drain
> work on every online CPU.
> 
> Signed-off-by: Nicolas Saenz Julienne <nsaenzju@xxxxxxxxxx>

Applied to cgroup/for-5.15.

Thanks.

-- 
tejun