Re: [PATCH 2/2] Filter unevictable page out in deactivate_page

Rik van Riel
2011-05-02T14:57:44Z

On 05/01/2011 11:03 AM, Minchan Kim wrote:
> It's pointless that deactive_page's pagevec operation about
> unevictable page as it's nop.
> This patch removes unnecessary overhead which might be a bit problem
> in case that there are many unevictable page in system(ex, mprotect workload)
>
> Signed-off-by: Minchan Kim<minchan.kim@gmail.com>
> ---
> mm/swap.c | 9 +++++++++
> 1 files changed, 9 insertions(+), 0 deletions(-)
>
> diff --git a/mm/swap.c b/mm/swap.c
> index 2e9656d..b707694 100644
> --- a/mm/swap.c
> +++ b/mm/swap.c
> @@ -511,6 +511,15 @@ static void drain_cpu_pagevecs(int cpu)
> */
> void deactivate_page(struct page *page)
> {
> +
> + /*
> + * In workload which system has many unevictable page(ex, mprotect),
> + * unevictalge page deactivation for accelerating reclaim

Typo.

> + * is pointless.
> + */
> + if (PageUnevictable(page))
> + return;
> +
> if (likely(get_page_unless_zero(page))) {
> struct pagevec *pvec =&get_cpu_var(lru_deactivate_pvecs);
>

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