Re: [PATCH RFC] mm: don't raise MEMCG_OOM event due to failed high-order allocation

From: peter enderborg
Date: Tue Sep 11 2018 - 08:41:09 EST


On 09/11/2018 02:11 PM, Michal Hocko wrote:
> Why is this a problem though? IIRC this event was deliberately placed
> outside of the oom path because we wanted to count allocation failures
> and this is also documented that way
>
> oom
> The number of time the cgroup's memory usage was
> reached the limit and allocation was about to fail.
>
> Depending on context result could be invocation of OOM
> killer and retrying allocation or failing a
>
> One could argue that we do not apply the same logic to GFP_NOWAIT
> requests but in general I would like to see a good reason to change
> the behavior and if it is really the right thing to do then we need to
> update the documentation as well.
>

Why not introduce a MEMCG_ALLOC_FAIL in to memcg_memory_event?