Re: [PATCH V3 3/3] mm: page_alloc: drain pcp lists before oom kill

[Charan Teja Kalla]

Thanks Michal!!

On 11/14/2023 4:18 PM, Michal Hocko wrote:
>> At least in my particular stress test case it just delayed the OOM as i
>> can see that at the time of OOM kill, there are no free pcp pages. My
>> understanding of the OOM is that it should be the last resort and only
>> after doing the enough reclaim retries. CMIW here.
> Yes it is a last resort but it is a heuristic as well. So the real
> questoin is whether this makes any practical difference outside of
> artificial workloads. I do not see anything particularly worrying to
> drain the pcp cache but it should be noted that this won't be 100%
> either as racing freeing of memory will end up on pcp lists first.

Okay, I don't have any practical scenario where this helped me in
avoiding the OOM.  Will comeback If I ever encounter this issue in
practical scenario.

Also If you have any comments on [PATCH V2 2/3] mm: page_alloc: correct
high atomic reserve calculations will help me.

Thanks.