Re: [PATCH 3/3] mm/memcg: add next_mz back if not reclaimed yet

[Michal Hocko <mhocko@suse.com>]

On Tue 08-03-22 01:20:47, Wei Yang wrote:
> next_mz is removed from rb_tree, let's add it back if no reclaim has
> been tried.

Could you elaborate more why we need/want this?

> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
> ---
>  mm/memcontrol.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 344a7e891bc5..e803ff02aae2 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -3493,8 +3493,13 @@ unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
>  			loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
>  			break;
>  	} while (!nr_reclaimed);
> -	if (next_mz)
> +	if (next_mz) {
> +		spin_lock_irq(&mctz->lock);
> +		excess = soft_limit_excess(next_mz->memcg);
> +		__mem_cgroup_insert_exceeded(next_mz, mctz, excess);
> +		spin_unlock_irq(&mctz->lock);
>  		css_put(&next_mz->memcg->css);
> +	}
>  	return nr_reclaimed;
>  }
>  
> -- 
> 2.33.1

-- 
Michal Hocko
SUSE Labs