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 <[email protected]>
Reviewed-by: Johannes Weiner <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Wu Fengguang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 20c5fa8eca466f603d7356584c2cbcaa3b81cc07..e219b47fc50baecb7bcab48cbdd3783388a9c716 100644 (file)
--- 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);