linux-kernel - [PATCH] [mmotm] don't attempt to reclaim anon page in lumpy reclaim when no swap space is avilable

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>] [day] [month] [year] [list]

Message-Id: <20090716194910.602446a4.minchan.kim@barrios-desktop>
Date:	Thu, 16 Jul 2009 19:49:10 +0900
From:	Minchan Kim <minchan.kim@...il.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	lkml <linux-kernel@...r.kernel.org>, Mel Gorman <mel@....ul.ie>,
	Rik van Riel <riel@...hat.com>,
	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	linux-mm <linux-mm@...ck.org>
Subject: [PATCH] [mmotm] don't attempt to reclaim anon page in lumpy reclaim
 when no swap space is avilable


This patch is based on mmotm 2009-07-15-20-57

This version is better than old one.
That's because enough swap space check is done in case of only lumpy reclaim.
so it can't degrade performance in normal case.

== CUT HERE ==

VM already avoids attempting to reclaim anon pages in various places, But
it doesn't avoid it for lumpy reclaim.

It shuffles lru list unnecessary so that it is pointless.

Signed-off-by: Minchan Kim <minchan.kim@...il.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
Reviewed-by: Rik van Riel <riel@...hat.com>
Cc: Mel Gorman <mel@....ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
---
 mm/vmscan.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 543596e..8b1132f 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -930,6 +930,15 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 			/* Check that we have not crossed a zone boundary. */
 			if (unlikely(page_zone_id(cursor_page) != zone_id))
 				continue;
+
+			/*
+			 * If we don't have enough swap space, reclaiming of anon page
+			 * which don't already have a swap slot is pointless.
+			 */
+			if (nr_swap_pages <= 0 && (PageAnon(cursor_page) &&
+									!PageSwapCache(cursor_page)))
+				continue;
+
 			if (__isolate_lru_page(cursor_page, mode, file) == 0) {
 				list_move(&cursor_page->lru, dst);
 				mem_cgroup_del_lru(cursor_page);
-- 
1.5.4.3


-- 
Kind regards,
Minchan Kim
--
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/