linux-kernel - [PATCH v3 04/10] compaction: make isolate_lru

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: <10ad16e14fdbe47ac36f7e55ae72ed59ae73ed0c.1307455422.git.minchan.kim@gmail.com>
Date:	Tue,  7 Jun 2011 23:38:17 +0900
From:	Minchan Kim <minchan.kim@...il.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	linux-mm <linux-mm@...ck.org>, LKML <linux-kernel@...r.kernel.org>,
	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>,
	Mel Gorman <mgorman@...e.de>,
	Andrea Arcangeli <aarcange@...hat.com>,
	Rik van Riel <riel@...hat.com>,
	Johannes Weiner <hannes@...xchg.org>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	Minchan Kim <minchan.kim@...il.com>
Subject: [PATCH v3 04/10] compaction: make isolate_lru_page with filter aware

In async mode, compaction doesn't migrate dirty or writeback pages.
So, it's meaningless to pick the page and re-add it to lru list.

Of course, when we isolate the page in compaction, the page might
be dirty or writeback but when we try to migrate the page, the page
would be not dirty, writeback. So it could be migrated. But it's
very unlikely as isolate and migration cycle is much faster than
writeout.

So, this patch helps cpu and prevent unnecessary LRU churning.

Cc: Andrea Arcangeli <aarcange@...hat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
Acked-by: Johannes Weiner <hannes@...xchg.org>
Acked-by: Mel Gorman <mgorman@...e.de>
Acked-by: Rik van Riel <riel@...hat.com>
Signed-off-by: Minchan Kim <minchan.kim@...il.com>
---
 mm/compaction.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/mm/compaction.c b/mm/compaction.c
index f0d75e9..8079346 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -243,6 +243,7 @@ static unsigned long isolate_migratepages(struct zone *zone,
 	unsigned long last_pageblock_nr = 0, pageblock_nr;
 	unsigned long nr_scanned = 0, nr_isolated = 0;
 	struct list_head *migratelist = &cc->migratepages;
+	enum ISOLATE_MODE mode = ISOLATE_ACTIVE|ISOLATE_INACTIVE;
 
 	/* Do not scan outside zone boundaries */
 	low_pfn = max(cc->migrate_pfn, zone->zone_start_pfn);
@@ -326,9 +327,11 @@ static unsigned long isolate_migratepages(struct zone *zone,
 			continue;
 		}
 
+		if (!cc->sync)
+			mode |= ISOLATE_CLEAN;
+ 
 		/* Try isolate the page */
-		if (__isolate_lru_page(page,
-				ISOLATE_ACTIVE|ISOLATE_INACTIVE, 0) != 0)
+		if (__isolate_lru_page(page, mode, 0) != 0)
 			continue;
 
 		VM_BUG_ON(PageTransCompound(page));
-- 
1.7.0.4

--
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/