From 7635eaa033cfcce7f351b5023952f23f0daffefe Mon Sep 17 00:00:00 2001
From: KOSAKI Motohiro<kosaki.motohiro@xxxxxxxxxxxxxx>
Date: Fri, 4 Dec 2009 12:03:07 +0900
Subject: [PATCH 5/7] Don't deactivate the page if trylock_page() is failed.
Currently, wipe_page_reference() increment refctx->referenced variable
if trylock_page() is failed. but it is meaningless at all.
shrink_active_list() deactivate the page although the page was
referenced. The page shouldn't be deactivated with young bit. it
break reclaim basic theory and decrease reclaim throughput.
This patch introduce new SWAP_AGAIN return value to
wipe_page_reference().
Signed-off-by: KOSAKI Motohiro<kosaki.motohiro@xxxxxxxxxxxxxx>