Re:[PATCH] sched/numa: initialize numa statistics when forking new task

From: Honglei Wang
Date: Mon Jan 17 2022 - 12:21:42 EST


Hello, friendly ping... any comments about this?

At 2022-01-13 21:39:20, "Honglei Wang" <wanghonglei@xxxxxxxxxxxxxxx> wrote:
>The child processes will inherit numa_pages_migrated and
>total_numa_faults from the parent. It means even if there is no numa
>fault happen on the child, the statistics in /proc/$pid of the child
>process might show huge amount. This is a bit weird. Let's initialize
>them when do fork.
>
>Signed-off-by: Honglei Wang <wanghonglei@xxxxxxxxxxxxxxx>
>---
> kernel/sched/fair.c | 2 ++
> 1 file changed, 2 insertions(+)
>
>diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
>index 6e476f6d9435..1aa0ec123a4b 100644
>--- a/kernel/sched/fair.c
>+++ b/kernel/sched/fair.c
>@@ -2826,6 +2826,8 @@ void init_numa_balancing(unsigned long clone_flags, struct task_struct *p)
> /* Protect against double add, see task_tick_numa and task_numa_work */
> p->numa_work.next = &p->numa_work;
> p->numa_faults = NULL;
>+ p->numa_pages_migrated = 0;
>+ p->total_numa_faults = 0;
> RCU_INIT_POINTER(p->numa_group, NULL);
> p->last_task_numa_placement = 0;
> p->last_sum_exec_runtime = 0;
>--
>2.14.1