Re: [PATCH] mm: Fix recent_rotated history

[Michal Hocko <mhocko@kernel.org>]

On Tue 28-05-19 19:09:02, Kirill Tkhai wrote:
> Johannes pointed that after commit 886cf1901db9
> we lost all zone_reclaim_stat::recent_rotated
> history. This commit fixes that.
> 
> Fixes: 886cf1901db9 "mm: move recent_rotated pages calculation to shrink_inactive_list()"
> Reported-by: Johannes Weiner <hannes@cmpxchg.org>
> Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>

I didn't get to review the original bug series but this one looks
obviously correct.

Acked-by: Michal Hocko <mhocko@suse.com>

> ---
>  mm/vmscan.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index d9c3e873eca6..1d49329a4d7d 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -1953,8 +1953,8 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
>  	if (global_reclaim(sc))
>  		__count_vm_events(item, nr_reclaimed);
>  	__count_memcg_events(lruvec_memcg(lruvec), item, nr_reclaimed);
> -	reclaim_stat->recent_rotated[0] = stat.nr_activate[0];
> -	reclaim_stat->recent_rotated[1] = stat.nr_activate[1];
> +	reclaim_stat->recent_rotated[0] += stat.nr_activate[0];
> +	reclaim_stat->recent_rotated[1] += stat.nr_activate[1];
>  
>  	move_pages_to_lru(lruvec, &page_list);
>  
> 

-- 
Michal Hocko
SUSE Labs