1 files changed, 45 insertions, 7 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 6be2068f61c8..1024979d6589 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1212,6 +1212,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 	unsigned long pgscanned;
 	unsigned long vm_flags;
 	LIST_HEAD(l_hold);	/* The pages which were snipped off */
+	LIST_HEAD(l_active);
 	LIST_HEAD(l_inactive);
 	struct page *page;
 	struct pagevec pvec;
@@ -1251,28 +1252,42 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 
 		/* page_referenced clears PageReferenced */
 		if (page_mapping_inuse(page) &&
-		    page_referenced(page, 0, sc->mem_cgroup, &vm_flags))
+		    page_referenced(page, 0, sc->mem_cgroup, &vm_flags)) {
 			pgmoved++;
+			/*
+			 * Identify referenced, file-backed active pages and
+			 * give them one more trip around the active list. So
+			 * that executable code get better chances to stay in
+			 * memory under moderate memory pressure.  Anon pages
+			 * are not likely to be evicted by use-once streaming
+			 * IO, plus JVM can create lots of anon VM_EXEC pages,
+			 * so we ignore them here.
+			 */
+			if ((vm_flags & VM_EXEC) && !PageAnon(page)) {
+				list_add(&page->lru, &l_active);
+				continue;
+			}
+		}
 
 		list_add(&page->lru, &l_inactive);
 	}
 
 	/*
-	 * Move the pages to the [file or anon] inactive list.
+	 * Move pages back to the lru list.
 	 */
 	pagevec_init(&pvec, 1);
-	lru = LRU_BASE + file * LRU_FILE;
 
 	spin_lock_irq(&zone->lru_lock);
 	/*
-	 * Count referenced pages from currently used mappings as
-	 * rotated, even though they are moved to the inactive list.
-	 * This helps balance scan pressure between file and anonymous
-	 * pages in get_scan_ratio.
+	 * Count referenced pages from currently used mappings as rotated,
+	 * even though only some of them are actually re-activated.  This
+	 * helps balance scan pressure between file and anonymous pages in
+	 * get_scan_ratio.
 	 */
 	reclaim_stat->recent_rotated[!!file] += pgmoved;
 
 	pgmoved = 0;  /* count pages moved to inactive list */
+	lru = LRU_BASE + file * LRU_FILE;
 	while (!list_empty(&l_inactive)) {
 		page = lru_to_page(&l_inactive);
 		prefetchw_prev_lru_page(page, &l_inactive, flags);
@@ -1295,6 +1310,29 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 	__mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
 	__count_zone_vm_events(PGREFILL, zone, pgscanned);
 	__count_vm_events(PGDEACTIVATE, pgmoved);
+
+	pgmoved = 0;  /* count pages moved back to active list */
+	lru = LRU_ACTIVE + file * LRU_FILE;
+	while (!list_empty(&l_active)) {
+		page = lru_to_page(&l_active);
+		prefetchw_prev_lru_page(page, &l_active, flags);
+		VM_BUG_ON(PageLRU(page));
+		SetPageLRU(page);
+		VM_BUG_ON(!PageActive(page));
+
+		list_move(&page->lru, &zone->lru[lru].list);
+		mem_cgroup_add_lru_list(page, lru);
+		pgmoved++;
+		if (!pagevec_add(&pvec, page)) {
+			spin_unlock_irq(&zone->lru_lock);
+			if (buffer_heads_over_limit)
+				pagevec_strip(&pvec);
+			__pagevec_release(&pvec);
+			spin_lock_irq(&zone->lru_lock);
+		}
+	}
+	__mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
+
 	spin_unlock_irq(&zone->lru_lock);
 	if (buffer_heads_over_limit)
 		pagevec_strip(&pvec);