linux-kernel - Re: [PATCH 2/2] Filter unevictable page out in deactivate

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20110502193820.2D60.A69D9226@jp.fujitsu.com>
Date:	Mon,  2 May 2011 19:37:30 +0900 (JST)
From:	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
To:	Minchan Kim <minchan.kim@...il.com>
Cc:	kosaki.motohiro@...fujitsu.com,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-mm <linux-mm@...ck.org>,
	LKML <linux-kernel@...r.kernel.org>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	Johannes Weiner <hannes@...xchg.org>,
	Rik van Riel <riel@...hat.com>, Mel Gorman <mgorman@...e.de>,
	Ying Han <yinghan@...gle.com>
Subject: Re: [PATCH 2/2] Filter unevictable page out in deactivate_page

> 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@...il.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
> +	 * is pointless.
> +	 */
> +	if (PageUnevictable(page))
> +		return;
> +

	Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>


btw, I think we should check PageLRU too.



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/