mm: add free_hot_cold_page_list() helper

This patch adds helper free_hot_cold_page_list() to free list of 0-order
pages.  It frees pages directly from list without temporary page-vector.
It also calls trace_mm_pagevec_free() to simulate pagevec_free()
behaviour.

bloat-o-meter:

add/remove: 1/1 grow/shrink: 1/3 up/down: 267/-295 (-28)
function                                     old     new   delta
free_hot_cold_page_list                        -     264    +264
get_page_from_freelist                      2129    2132      +3
__pagevec_free                               243     239      -4
split_free_page                              380     373      -7
release_pages                                606     510     -96
free_page_list                               188       -    -188

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 11 deletions

diff --git a/mm/swap.c b/mm/swap.c
index a91caf7..67a09a6 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -585,11 +585,10 @@ int lru_add_drain_all(void)
 void release_pages(struct page **pages, int nr, int cold)
 {
 	int i;
-	struct pagevec pages_to_free;
+	LIST_HEAD(pages_to_free);
 	struct zone *zone = NULL;
 	unsigned long uninitialized_var(flags);
 
-	pagevec_init(&pages_to_free, cold);
 	for (i = 0; i < nr; i++) {
 		struct page *page = pages[i];
 
@@ -620,19 +619,12 @@ void release_pages(struct page **pages, int nr, int cold)
 			del_page_from_lru(zone, page);
 		}
 
-		if (!pagevec_add(&pages_to_free, page)) {
-			if (zone) {
-				spin_unlock_irqrestore(&zone->lru_lock, flags);
-				zone = NULL;
-			}
-			__pagevec_free(&pages_to_free);
-			pagevec_reinit(&pages_to_free);
-  		}
+		list_add(&page->lru, &pages_to_free);
 	}
 	if (zone)
 		spin_unlock_irqrestore(&zone->lru_lock, flags);
 
-	pagevec_free(&pages_to_free);
+	free_hot_cold_page_list(&pages_to_free, cold);
 }
 EXPORT_SYMBOL(release_pages);