Re: [PATCH] sched/numa: Add statistics of numa balance task migration and swap

[K Prateek Nayak]

Hello Michal,

On 4/2/2025 6:54 PM, Michal Koutný wrote:
> Hello Chen.
>
> On Wed, Apr 02, 2025 at 09:06:11AM +0800, Chen Yu <yu.c.chen@xxxxxxxxx> wrote:
> > On system with NUMA balancing enabled, it is found that tracking
> > the task activities due to NUMA balancing is helpful.
> ...
> > The following two new fields:
> >
> > numa_task_migrated
> > numa_task_swapped
> >
> > will be displayed in both
> > /sys/fs/cgroup/{GROUP}/memory.stat and /proc/{PID}/sched
>
> Why is the field /proc/$pid/sched not enough?

The /proc/$pid/sched accounting is only done when schedstats are
enabled. memcg users might want to track it separately without relying
on schedstats which also enables a bunch of other scheduler related
stats collection adding more overheads.

> Also, you may want to update Documentation/admin-guide/cgroup-v2.rst
> too.
>
> Thanks,
> Michal

--
Thanks and Regards,
Prateek