[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20101019113558.A1D5.A69D9226@jp.fujitsu.com>
Date: Tue, 19 Oct 2010 11:37:00 +0900 (JST)
From: KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
To: Wu Fengguang <fengguang.wu@...el.com>
Cc: kosaki.motohiro@...fujitsu.com,
Andrew Morton <akpm@...ux-foundation.org>,
Neil Brown <neilb@...e.de>, Rik van Riel <riel@...hat.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"linux-mm@...ck.org" <linux-mm@...ck.org>,
"Li, Shaohua" <shaohua.li@...el.com>
Subject: Re: Deadlock possibly caused by too_many_isolated.
> ---
> Subject: vmscan: comment too_many_isolated()
> From: Wu Fengguang <fengguang.wu@...el.com>
> Date: Tue Oct 19 09:53:23 CST 2010
>
> Comment "Why it's doing so" rather than "What it does"
> as proposed by Andrew Morton.
>
> Signed-off-by: Wu Fengguang <fengguang.wu@...el.com>
> ---
> mm/vmscan.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> --- linux-next.orig/mm/vmscan.c 2010-10-19 09:29:44.000000000 +0800
> +++ linux-next/mm/vmscan.c 2010-10-19 10:21:41.000000000 +0800
> @@ -1142,7 +1142,11 @@ int isolate_lru_page(struct page *page)
> }
>
> /*
> - * Are there way too many processes in the direct reclaim path already?
> + * A direct reclaimer may isolate SWAP_CLUSTER_MAX pages from the LRU list and
> + * then get resheduled. When there are massive number of tasks doing page
> + * allocation, such sleeping direct reclaimers may keep piling up on each CPU,
> + * the LRU list will go small and be scanned faster than necessary, leading to
> + * unnecessary swapping, thrashing and OOM.
> */
> static int too_many_isolated(struct zone *zone, int file,
> struct scan_control *sc)
nice!
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
--
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/
Powered by blists - more mailing lists