On Tue, 22 Aug 2023, Michal Hocko wrote:
Yes, this doesn't really show any actual correctness problem so I do not think this is sufficient to change the code. You would need to show that the existing behavior is actively harmful.
Having some pages from a remote NUMA node stuck in a pcp somewhere is making that memory unusable. It is usually rate that these remote pages are needed again and so they may remain there for a long time if the situation is right.
And he is right that the intended behavior of freeing the remote pages has been disabled by the patch.
So I think there is sufficient rationale to apply these fixes.
