From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Date: Tue, 22 Sep 2009 00:01:46 +0000 (-0700)
Subject: vmscan: kill unnecessary prefetch
X-Git-Tag: firefly_0821_release~12846
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=a26f5320c4ee3d46a0da48fa0f3ac6a00b575793;p=firefly-linux-kernel-4.4.55.git

vmscan: kill unnecessary prefetch

The pages in the list passed move_active_pages_to_lru() are already
touched by shrink_active_list().  IOW the prefetch in
move_active_pages_to_lru() don't populate any cache.  it's pointless.

This patch remove it.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 20c5fa8eca46..e219b47fc50b 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1273,7 +1273,6 @@ static void move_active_pages_to_lru(struct zone *zone,
 
 	while (!list_empty(list)) {
 		page = lru_to_page(list);
-		prefetchw_prev_lru_page(page, list, flags);
 
 		VM_BUG_ON(PageLRU(page));
 		SetPageLRU(page);