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

[Shakeel Butt]

On Mon, Feb 02, 2026 at 02:23:54PM +0530, Dev Jain wrote:
> 
> 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.
> 

Hi Dev, can you please try the following patch?