Re: [PATCH] mm, memcg: unify reclaim retry limits with page allocator

From: Shakeel Butt
Date: Fri May 22 2020 - 10:08:12 EST


On Wed, May 20, 2020 at 9:32 AM Chris Down <chris@xxxxxxxxxxxxxx> wrote:
>
> Reclaim retries have been set to 5 since the beginning of time in
> 66e1707bc346 ("Memory controller: add per cgroup LRU and reclaim").
> However, we now have a generally agreed-upon standard for page reclaim:
> MAX_RECLAIM_RETRIES (currently 16), added many years later in
> 0a0337e0d1d1 ("mm, oom: rework oom detection").
>
> In the absence of a compelling reason to declare an OOM earlier in memcg
> context than page allocator context, it seems reasonable to supplant
> MEM_CGROUP_RECLAIM_RETRIES with MAX_RECLAIM_RETRIES, making the page
> allocator and memcg internals more similar in semantics when reclaim
> fails to produce results, avoiding premature OOMs or throttling.
>
> Signed-off-by: Chris Down <chris@xxxxxxxxxxxxxx>

Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx>