Re: [PATCH 1/4] memcg: use mod_node_page_state to update stats

[Dev Jain]

On 02/02/26 10:24 am, Shakeel Butt wrote:
>>>> Hello Shakeel,
>>>>
>>>>  We are seeing a regression in micromm/munmap benchmark with this patch, on arm64 -
>>>>  the benchmark mmmaps a lot of memory, memsets it, and measures the time taken
>>>>  to munmap. Please see below if my understanding of this patch is correct.
>>>>
>>>  Thanks for the report. Are you seeing regression in just the benchmark
>>>  or some real workload as well? Also how much regression are you seeing?
>>>  I have a kernel rebot regression report [1] for this patch as well which
>>>  says 2.6% regression and thus it was on the back-burner for now. I will
>>>  take look at this again soon.
>>>
>> The munmap regression is ~24%. Haven't observed a regression in any other
>> benchmark yet.
> Please share the code/benchmark which shows such regression, also if you can
> share the perf profile, that would be awesome.

https://gitlab.arm.com/tooling/fastpath/-/blob/main/containers/microbench/micromm.c
You can run this with
./micromm 0 munmap 10

Don't have a perf profile, I measured the time taken by above command, with and
without the patch.