[PATCH] Optimize free_one_page

Free one_page currently adds the page to a fake list and calls
free_page_bulk.  Fee_page_bulk takes it off again and then calles
__free_one_page.

Make free_one_page go directly to __free_one_page.  Saves list on / off and
a temporary list in free_one_page for higher ordered pages.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

mm/page_alloc.c

@@ -448,9 +448,11 @@ static void free_pages_bulk(struct zone *zone, int count,
 
 static void free_one_page(struct zone *zone, struct page *page, int order)
 {
-	LIST_HEAD(list);
-	list_add(&page->lru, &list);
-	free_pages_bulk(zone, 1, &list, order);
+	spin_lock(&zone->lock);
+	zone->all_unreclaimable = 0;
+	zone->pages_scanned = 0;
+	__free_one_page(page, zone ,order);
+	spin_unlock(&zone->lock);
 }
 
 static void __free_pages_ok(struct page *page, unsigned int order)