Re: [PATCH v2 2/3] sched/numa: expose per-task pages-migration-failure

[çè]

Hi, Peter,

This has been acked by Mel Gorman, since it is not much related
with the rest patches, would you like to pick this one now?

Regards,
Michael Wang

On 2019/11/27 äå9:50, çè wrote:
> NUMA balancing will try to migrate pages between nodes, which
> could caused by memory policy or numa group aggregation, while
> the page migration could failed too for eg when the target node
> run out of memory.
> 
> Since this is critical to the performance, admin should know
> how serious the problem is, and take actions before it causing
> too much performance damage, thus this patch expose the counter
> as 'migfailed' in '/proc/PID/sched'.
> 
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Michal Koutnà <mkoutny@xxxxxxxx>
> Suggested-by: Mel Gorman <mgorman@xxxxxxx>
> Signed-off-by: Michael Wang <yun.wang@xxxxxxxxxxxxxxxxx>
> ---
>  kernel/sched/debug.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
> index f7e4579e746c..73c4809c8f37 100644
> --- a/kernel/sched/debug.c
> +++ b/kernel/sched/debug.c
> @@ -848,6 +848,7 @@ static void sched_show_numa(struct task_struct *p, struct seq_file *m)
>  	P(total_numa_faults);
>  	SEQ_printf(m, "current_node=%d, numa_group_id=%d\n",
>  			task_node(p), task_numa_group_id(p));
> +	SEQ_printf(m, "migfailed=%lu\n", p->numa_faults_locality[2]);
>  	show_numa_stats(p, m);
>  	mpol_put(pol);
>  #endif
>