Re: [PATCH REBASED] mm, memcg: Make scan aggression always exclude protection

From: Chris Down
Date: Thu May 30 2019 - 02:48:29 EST


Michal Hocko writes:
Maybe I am missing something so correct me if I am wrong but the new
calculation actually means that we always allow to scan even min
protected memcgs right?

We check if the memcg is min protected as a precondition for coming into this function at all, so this generally isn't possible. See the mem_cgroup_protected MEMCG_PROT_MIN check in shrink_node.

(Of course, it's possible we race with going within protection thresholds again, but this patch doesn't make that any better or worse than the previous situation.)