Re: [PATCH] mm: correct the comment when reclaimed pages exceed the scanned pages

From: zhong jiang
Date: Thu Jun 08 2017 - 00:53:47 EST


On 2017/6/7 16:31, zhongjiang wrote:
> The commit e1587a494540 ("mm: vmpressure: fix sending wrong events on
> underflow") declare that reclaimed pages exceed the scanned pages due
> to the thp reclaim. it is incorrect because THP will be spilt to normal
> page and loop again. which will result in the scanned pages increment.
>
> Signed-off-by: zhongjiang <zhongjiang@xxxxxxxxxx>
> ---
> mm/vmpressure.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/mm/vmpressure.c b/mm/vmpressure.c
> index 6063581..0e91ba3 100644
> --- a/mm/vmpressure.c
> +++ b/mm/vmpressure.c
> @@ -116,8 +116,9 @@ static enum vmpressure_levels vmpressure_calc_level(unsigned long scanned,
>
> /*
> * reclaimed can be greater than scanned in cases
> - * like THP, where the scanned is 1 and reclaimed
> - * could be 512
> + * like reclaimed slab pages, shrink_node just add
> + * reclaimed page without a related increment to
> + * scanned pages.
> */
> if (reclaimed >= scanned)
> goto out;
Hi, minchan

what suggstion about the patch

Thanks
zhongjiang