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

[Chen, Yu C]

On 4/3/2025 1:35 AM, K Prateek Nayak wrote:
> Hello Chenyu,
>
> On 4/2/2025 6:36 AM, Chen Yu wrote:
> > On system with NUMA balancing enabled, it is found that tracking
> > the task activities due to NUMA balancing is helpful. NUMA balancing
> > has two mechanisms for task migration: one is to migrate the task to
> > an idle CPU in its preferred node, the other is to swap tasks on
> > different nodes if they are on each other's preferred node.
> >
> > The kernel already has NUMA page migration statistics in
> > /sys/fs/cgroup/mytest/memory.stat and /proc/{PID}/sched.
> > but does not have statistics for task migration/swap.
> > Add the task migration and swap count accordingly.
> >
> > 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
>
> Running sched-messaging with schedstats enabled, I could see both
> "numa_task_migrated" and "numa_task_swapped" being populated for the
> sched-messaging threads:
>
> $ for i in $(ls /proc/4030/task/); do grep "numa_task_migrated" /proc/ 
> $i/sched; done | tr -s ' ' | cut -d ' ' -f3 | sort | uniq -c
>      400 0
>      231 1
>       10 2
>
> $ for i in $(ls /proc/4030/task/); do grep "numa_task_swapped" /proc/$i/ 
> sched; done | tr -s ' ' | cut -d ' ' -f3 | sort | uniq -c
>      389 0
>      193 1
>       47 2
>       11 3
>        1 4
>
> > Previous RFC version can be found here:
> > https://lore.kernel.org/ 
> > lkml/1847c5ef828ad4835a35e3a54b88d2e13bce0eea.1740483690.git.yu.c.chen@xxxxxxxxx/
> >
> > Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx>
>
> Feel free to add:
>
> Tested-by: K Prateek Nayak <kprateek.nayak@xxxxxxx>


Thanks Prateek!

Thanks,
Chenyu