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

[Rik van Riel <riel@redhat.com>]

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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