Re: [PATCH] mm: memcontrol: drain memcg stock on force_empty

[Shakeel Butt]

On Mon, May 7, 2018 at 1:16 PM Shakeel Butt <shakeelb@xxxxxxxxxx> wrote:

> From: Junaid Shahid <junaids@xxxxxxxxxx>

> The per-cpu memcg stock can retain a charge of upto 32 pages. On a
> machine with large number of cpus, this can amount to a decent amount
> of memory. Additionally force_empty interface might be triggering
> unneeded memcg reclaims.

> Signed-off-by: Junaid Shahid <juanids@xxxxxxxxxx>

This should be "Junaid Shahid <junaids@xxxxxxxxxx>".

> Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
> ---
>   mm/memcontrol.c | 3 +++
>   1 file changed, 3 insertions(+)

> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index e2d33a37f971..2c3c69524b49 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -2841,6 +2841,9 @@ static int mem_cgroup_force_empty(struct mem_cgroup
*memcg)

>          /* we call try-to-free pages for make this cgroup empty */
>          lru_add_drain_all();
> +
> +       drain_all_stock(memcg);
> +
>          /* try to free all pages in this cgroup */
>          while (nr_retries && page_counter_read(&memcg->memory)) {
>                  int progress;
> --
> 2.17.0.441.gb46fe60e1d-goog