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

["Chen, Yu C" <yu.c.chen@intel.com>]

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@intel.com/
>>
>> Signed-off-by: Chen Yu <yu.c.chen@intel.com>
> 
> Feel free to add:
> 
> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
> 


Thanks Prateek!

Thanks,
Chenyu