mm: memcontrol: use page lists for uncharge batching

Pages are now uncharged at release time, and all sources of batched
uncharges operate on lists of pages.  Directly use those lists, and
get rid of the per-task batching state.

This also batches statistics accounting, in addition to the res
counter charges, to reduce IRQ-disabling and re-enabling.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 5 deletions

diff --git a/mm/swap.c b/mm/swap.c
index 00523fffa5ed..6b2dc3897cd5 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -908,8 +908,6 @@ void release_pages(struct page **pages, int nr, bool cold)
 	struct lruvec *lruvec;
 	unsigned long uninitialized_var(flags);
 
-	mem_cgroup_uncharge_start();
-
 	for (i = 0; i < nr; i++) {
 		struct page *page = pages[i];
 
@@ -941,7 +939,6 @@ void release_pages(struct page **pages, int nr, bool cold)
 			__ClearPageLRU(page);
 			del_page_from_lru_list(page, lruvec, page_off_lru(page));
 		}
-		mem_cgroup_uncharge(page);
 
 		/* Clear Active bit in case of parallel mark_page_accessed */
 		__ClearPageActive(page);
@@ -951,8 +948,7 @@ void release_pages(struct page **pages, int nr, bool cold)
 	if (zone)
 		spin_unlock_irqrestore(&zone->lru_lock, flags);
 
-	mem_cgroup_uncharge_end();
-
+	mem_cgroup_uncharge_list(&pages_to_free);
 	free_hot_cold_page_list(&pages_to_free, cold);
 }
 EXPORT_SYMBOL(release_pages);