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

[Madadi Vineeth Reddy]

Hi Chen Yu,

On 02/04/25 06:36, 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

I was able to see the fields and their corresponding values for schbench:

numa_task_swapped                            :                    2
numa_task_migrated                           :                    0
numa_task_swapped                            :                    1
numa_task_migrated                           :                    0
numa_task_swapped                            :                    0
numa_task_migrated                           :                    0
numa_task_swapped                            :                    1

Tested-by: Madadi Vineeth Reddy <vineethr@xxxxxxxxxxxxx>

Thanks,
Madadi Vineeth Reddy

> 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>
> ---
> RFC->v1: Rename the nr_numa_task_migrated to
>          numa_task_migrated, and nr_numa_task_swapped
>          numa_task_swapped in /proc/{PID}/sched,
>          so both cgroup's memory.stat and task's
>          sched have the same field name.
> ---
>  include/linux/sched.h         |  4 ++++
>  include/linux/vm_event_item.h |  2 ++
>  kernel/sched/core.c           | 10 ++++++++--
>  kernel/sched/debug.c          |  4 ++++
>  mm/memcontrol.c               |  2 ++
>  mm/vmstat.c                   |  2 ++
>  6 files changed, 22 insertions(+), 2 deletions(-)