vmscan: split LRU lists into anon & file sets

Split the LRU lists in two, one set for pages that are backed by real file
systems ("file") and one for pages that are backed by memory and swap
("anon").  The latter includes tmpfs.

The advantage of doing this is that the VM will not have to scan over lots
of anonymous pages (which we generally do not want to swap out), just to
find the page cache pages that it should evict.

This patch has the infrastructure and a basic policy to balance how much
we scan the anon lists and how much we scan the file lists.  The big
policy changes are in separate patches.

[lee.schermerhorn@hp.com: collect lru meminfo statistics from correct offset]
[kosaki.motohiro@jp.fujitsu.com: prevent incorrect oom under split_lru]
[kosaki.motohiro@jp.fujitsu.com: fix pagevec_move_tail() doesn't treat unevictable page]
[hugh@veritas.com: memcg swapbacked pages active]
[hugh@veritas.com: splitlru: BDI_CAP_SWAP_BACKED]
[akpm@linux-foundation.org: fix /proc/vmstat units]
[nishimura@mxp.nes.nec.co.jp: memcg: fix handling of shmem migration]
[kosaki.motohiro@jp.fujitsu.com: adjust Quicklists field of /proc/meminfo]
[kosaki.motohiro@jp.fujitsu.com: fix style issue of get_scan_ratio()]
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 216 insertions, 200 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index e656035..d10d2f9 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -78,7 +78,7 @@ struct scan_control {
 	unsigned long (*isolate_pages)(unsigned long nr, struct list_head *dst,
 			unsigned long *scanned, int order, int mode,
 			struct zone *z, struct mem_cgroup *mem_cont,
-			int active);
+			int active, int file);
 };
 
 #define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru))
@@ -680,7 +680,7 @@ keep:
  *
  * returns 0 on success, -ve errno on failure.
  */
-int __isolate_lru_page(struct page *page, int mode)
+int __isolate_lru_page(struct page *page, int mode, int file)
 {
 	int ret = -EINVAL;
 
@@ -696,6 +696,9 @@ int __isolate_lru_page(struct page *page, int mode)
 	if (mode != ISOLATE_BOTH && (!PageActive(page) != !mode))
 		return ret;
 
+	if (mode != ISOLATE_BOTH && (!page_is_file_cache(page) != !file))
+		return ret;
+
 	ret = -EBUSY;
 	if (likely(get_page_unless_zero(page))) {
 		/*
@@ -726,12 +729,13 @@ int __isolate_lru_page(struct page *page, int mode)
  * @scanned:	The number of pages that were scanned.
  * @order:	The caller's attempted allocation order
  * @mode:	One of the LRU isolation modes
+ * @file:	True [1] if isolating file [!anon] pages
  *
  * returns how many pages were moved onto *@dst.
  */
 static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 		struct list_head *src, struct list_head *dst,
-		unsigned long *scanned, int order, int mode)
+		unsigned long *scanned, int order, int mode, int file)
 {
 	unsigned long nr_taken = 0;
 	unsigned long scan;
@@ -748,7 +752,7 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 
 		VM_BUG_ON(!PageLRU(page));
 
-		switch (__isolate_lru_page(page, mode)) {
+		switch (__isolate_lru_page(page, mode, file)) {
 		case 0:
 			list_move(&page->lru, dst);
 			nr_taken++;
@@ -791,10 +795,11 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 				break;
 
 			cursor_page = pfn_to_page(pfn);
+
 			/* Check that we have not crossed a zone boundary. */
 			if (unlikely(page_zone_id(cursor_page) != zone_id))
 				continue;
-			switch (__isolate_lru_page(cursor_page, mode)) {
+			switch (__isolate_lru_page(cursor_page, mode, file)) {
 			case 0:
 				list_move(&cursor_page->lru, dst);
 				nr_taken++;
@@ -819,30 +824,37 @@ static unsigned long isolate_pages_global(unsigned long nr,
 					unsigned long *scanned, int order,
 					int mode, struct zone *z,
 					struct mem_cgroup *mem_cont,
-					int active)
+					int active, int file)
 {
+	int lru = LRU_BASE;
 	if (active)
-		return isolate_lru_pages(nr, &z->lru[LRU_ACTIVE].list, dst,
-						scanned, order, mode);
-	else
-		return isolate_lru_pages(nr, &z->lru[LRU_INACTIVE].list, dst,
-						scanned, order, mode);
+		lru += LRU_ACTIVE;
+	if (file)
+		lru += LRU_FILE;
+	return isolate_lru_pages(nr, &z->lru[lru].list, dst, scanned, order,
+								mode, !!file);
 }
 
 /*
  * clear_active_flags() is a helper for shrink_active_list(), clearing
  * any active bits from the pages in the list.
  */
-static unsigned long clear_active_flags(struct list_head *page_list)
+static unsigned long clear_active_flags(struct list_head *page_list,
+					unsigned int *count)
 {
 	int nr_active = 0;
+	int lru;
 	struct page *page;
 
-	list_for_each_entry(page, page_list, lru)
+	list_for_each_entry(page, page_list, lru) {
+		lru = page_is_file_cache(page);
 		if (PageActive(page)) {
+			lru += LRU_ACTIVE;
 			ClearPageActive(page);
 			nr_active++;
 		}
+		count[lru]++;
+	}
 
 	return nr_active;
 }
@@ -880,12 +892,12 @@ int isolate_lru_page(struct page *page)
 
 		spin_lock_irq(&zone->lru_lock);
 		if (PageLRU(page) && get_page_unless_zero(page)) {
+			int lru = LRU_BASE;
 			ret = 0;
 			ClearPageLRU(page);
-			if (PageActive(page))
-				del_page_from_active_list(zone, page);
-			else
-				del_page_from_inactive_list(zone, page);
+
+			lru += page_is_file_cache(page) + !!PageActive(page);
+			del_page_from_lru_list(zone, page, lru);
 		}
 		spin_unlock_irq(&zone->lru_lock);
 	}
@@ -897,7 +909,7 @@ int isolate_lru_page(struct page *page)
  * of reclaimed pages
  */
 static unsigned long shrink_inactive_list(unsigned long max_scan,
-				struct zone *zone, struct scan_control *sc)
+			struct zone *zone, struct scan_control *sc, int file)
 {
 	LIST_HEAD(page_list);
 	struct pagevec pvec;
@@ -914,20 +926,32 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
 		unsigned long nr_scan;
 		unsigned long nr_freed;
 		unsigned long nr_active;
+		unsigned int count[NR_LRU_LISTS] = { 0, };
+		int mode = (sc->order > PAGE_ALLOC_COSTLY_ORDER) ?
+					ISOLATE_BOTH : ISOLATE_INACTIVE;
 
 		nr_taken = sc->isolate_pages(sc->swap_cluster_max,
-			     &page_list, &nr_scan, sc->order,
-			     (sc->order > PAGE_ALLOC_COSTLY_ORDER)?
-					     ISOLATE_BOTH : ISOLATE_INACTIVE,
-				zone, sc->mem_cgroup, 0);
-		nr_active = clear_active_flags(&page_list);
+			     &page_list, &nr_scan, sc->order, mode,
+				zone, sc->mem_cgroup, 0, file);
+		nr_active = clear_active_flags(&page_list, count);
 		__count_vm_events(PGDEACTIVATE, nr_active);
 
-		__mod_zone_page_state(zone, NR_ACTIVE, -nr_active);
-		__mod_zone_page_state(zone, NR_INACTIVE,
-						-(nr_taken - nr_active));
-		if (scan_global_lru(sc))
+		__mod_zone_page_state(zone, NR_ACTIVE_FILE,
+						-count[LRU_ACTIVE_FILE]);
+		__mod_zone_page_state(zone, NR_INACTIVE_FILE,
+						-count[LRU_INACTIVE_FILE]);
+		__mod_zone_page_state(zone, NR_ACTIVE_ANON,
+						-count[LRU_ACTIVE_ANON]);
+		__mod_zone_page_state(zone, NR_INACTIVE_ANON,
+						-count[LRU_INACTIVE_ANON]);
+
+		if (scan_global_lru(sc)) {
 			zone->pages_scanned += nr_scan;
+			zone->recent_scanned[0] += count[LRU_INACTIVE_ANON];
+			zone->recent_scanned[0] += count[LRU_ACTIVE_ANON];
+			zone->recent_scanned[1] += count[LRU_INACTIVE_FILE];
+			zone->recent_scanned[1] += count[LRU_ACTIVE_FILE];
+		}
 		spin_unlock_irq(&zone->lru_lock);
 
 		nr_scanned += nr_scan;
@@ -947,7 +971,7 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
 			 * The attempt at page out may have made some
 			 * of the pages active, mark them inactive again.
 			 */
-			nr_active = clear_active_flags(&page_list);
+			nr_active = clear_active_flags(&page_list, count);
 			count_vm_events(PGDEACTIVATE, nr_active);
 
 			nr_freed += shrink_page_list(&page_list, sc,
@@ -977,6 +1001,10 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
 			SetPageLRU(page);
 			list_del(&page->lru);
 			add_page_to_lru_list(zone, page, page_lru(page));
+			if (PageActive(page) && scan_global_lru(sc)) {
+				int file = !!page_is_file_cache(page);
+				zone->recent_rotated[file]++;
+			}
 			if (!pagevec_add(&pvec, page)) {
 				spin_unlock_irq(&zone->lru_lock);
 				__pagevec_release(&pvec);
@@ -1007,115 +1035,7 @@ static inline void note_zone_scanning_priority(struct zone *zone, int priority)
 
 static inline int zone_is_near_oom(struct zone *zone)
 {
-	return zone->pages_scanned >= (zone_page_state(zone, NR_ACTIVE)
-				+ zone_page_state(zone, NR_INACTIVE))*3;
-}
-
-/*
- * Determine we should try to reclaim mapped pages.
- * This is called only when sc->mem_cgroup is NULL.
- */
-static int calc_reclaim_mapped(struct scan_control *sc, struct zone *zone,
-				int priority)
-{
-	long mapped_ratio;
-	long distress;
-	long swap_tendency;
-	long imbalance;
-	int reclaim_mapped = 0;
-	int prev_priority;
-
-	if (scan_global_lru(sc) && zone_is_near_oom(zone))
-		return 1;
-	/*
-	 * `distress' is a measure of how much trouble we're having
-	 * reclaiming pages.  0 -> no problems.  100 -> great trouble.
-	 */
-	if (scan_global_lru(sc))
-		prev_priority = zone->prev_priority;
-	else
-		prev_priority = mem_cgroup_get_reclaim_priority(sc->mem_cgroup);
-
-	distress = 100 >> min(prev_priority, priority);
-
-	/*
-	 * The point of this algorithm is to decide when to start
-	 * reclaiming mapped memory instead of just pagecache.  Work out
-	 * how much memory
-	 * is mapped.
-	 */
-	if (scan_global_lru(sc))
-		mapped_ratio = ((global_page_state(NR_FILE_MAPPED) +
-				global_page_state(NR_ANON_PAGES)) * 100) /
-					vm_total_pages;
-	else
-		mapped_ratio = mem_cgroup_calc_mapped_ratio(sc->mem_cgroup);
-
-	/*
-	 * Now decide how much we really want to unmap some pages.  The
-	 * mapped ratio is downgraded - just because there's a lot of
-	 * mapped memory doesn't necessarily mean that page reclaim
-	 * isn't succeeding.
-	 *
-	 * The distress ratio is important - we don't want to start
-	 * going oom.
-	 *
-	 * A 100% value of vm_swappiness overrides this algorithm
-	 * altogether.
-	 */
-	swap_tendency = mapped_ratio / 2 + distress + sc->swappiness;
-
-	/*
-	 * If there's huge imbalance between active and inactive
-	 * (think active 100 times larger than inactive) we should
-	 * become more permissive, or the system will take too much
-	 * cpu before it start swapping during memory pressure.
-	 * Distress is about avoiding early-oom, this is about
-	 * making swappiness graceful despite setting it to low
-	 * values.
-	 *
-	 * Avoid div by zero with nr_inactive+1, and max resulting
-	 * value is vm_total_pages.
-	 */
-	if (scan_global_lru(sc)) {
-		imbalance  = zone_page_state(zone, NR_ACTIVE);
-		imbalance /= zone_page_state(zone, NR_INACTIVE) + 1;
-	} else
-		imbalance = mem_cgroup_reclaim_imbalance(sc->mem_cgroup);
-
-	/*
-	 * Reduce the effect of imbalance if swappiness is low,
-	 * this means for a swappiness very low, the imbalance
-	 * must be much higher than 100 for this logic to make
-	 * the difference.
-	 *
-	 * Max temporary value is vm_total_pages*100.
-	 */
-	imbalance *= (vm_swappiness + 1);
-	imbalance /= 100;
-
-	/*
-	 * If not much of the ram is mapped, makes the imbalance
-	 * less relevant, it's high priority we refill the inactive
-	 * list with mapped pages only in presence of high ratio of
-	 * mapped pages.
-	 *
-	 * Max temporary value is vm_total_pages*100.
-	 */
-	imbalance *= mapped_ratio;
-	imbalance /= 100;
-
-	/* apply imbalance feedback to swap_tendency */
-	swap_tendency += imbalance;
-
-	/*
-	 * Now use this metric to decide whether to start moving mapped
-	 * memory onto the inactive list.
-	 */
-	if (swap_tendency >= 100)
-		reclaim_mapped = 1;
-
-	return reclaim_mapped;
+	return zone->pages_scanned >= (zone_lru_pages(zone) * 3);
 }
 
 /*
@@ -1138,7 +1058,7 @@ static int calc_reclaim_mapped(struct scan_control *sc, struct zone *zone,
 
 
 static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
-				struct scan_control *sc, int priority)
+			struct scan_control *sc, int priority, int file)
 {
 	unsigned long pgmoved;
 	int pgdeactivate = 0;
@@ -1148,43 +1068,42 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 	LIST_HEAD(l_inactive);
 	struct page *page;
 	struct pagevec pvec;
-	int reclaim_mapped = 0;
-
-	if (sc->may_swap)
-		reclaim_mapped = calc_reclaim_mapped(sc, zone, priority);
+	enum lru_list lru;
 
 	lru_add_drain();
 	spin_lock_irq(&zone->lru_lock);
 	pgmoved = sc->isolate_pages(nr_pages, &l_hold, &pgscanned, sc->order,
 					ISOLATE_ACTIVE, zone,
-					sc->mem_cgroup, 1);
+					sc->mem_cgroup, 1, file);
 	/*
 	 * zone->pages_scanned is used for detect zone's oom
 	 * mem_cgroup remembers nr_scan by itself.
 	 */
-	if (scan_global_lru(sc))
+	if (scan_global_lru(sc)) {
 		zone->pages_scanned += pgscanned;
+		zone->recent_scanned[!!file] += pgmoved;
+	}
 
-	__mod_zone_page_state(zone, NR_ACTIVE, -pgmoved);
+	if (file)
+		__mod_zone_page_state(zone, NR_ACTIVE_FILE, -pgmoved);
+	else
+		__mod_zone_page_state(zone, NR_ACTIVE_ANON, -pgmoved);
 	spin_unlock_irq(&zone->lru_lock);
 
 	while (!list_empty(&l_hold)) {
 		cond_resched();
 		page = lru_to_page(&l_hold);
 		list_del(&page->lru);
-		if (page_mapped(page)) {
-			if (!reclaim_mapped ||
-			    (total_swap_pages == 0 && PageAnon(page)) ||
-			    page_referenced(page, 0, sc->mem_cgroup)) {
-				list_add(&page->lru, &l_active);
-				continue;
-			}
-		}
 		list_add(&page->lru, &l_inactive);
 	}
 
+	/*
+	 * Now put the pages back on the appropriate [file or anon] inactive
+	 * and active lists.
+	 */
 	pagevec_init(&pvec, 1);
 	pgmoved = 0;
+	lru = LRU_BASE + file * LRU_FILE;
 	spin_lock_irq(&zone->lru_lock);
 	while (!list_empty(&l_inactive)) {
 		page = lru_to_page(&l_inactive);
@@ -1194,11 +1113,11 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 		VM_BUG_ON(!PageActive(page));
 		ClearPageActive(page);
 
-		list_move(&page->lru, &zone->lru[LRU_INACTIVE].list);
+		list_move(&page->lru, &zone->lru[lru].list);
 		mem_cgroup_move_lists(page, false);
 		pgmoved++;
 		if (!pagevec_add(&pvec, page)) {
-			__mod_zone_page_state(zone, NR_INACTIVE, pgmoved);
+			__mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
 			spin_unlock_irq(&zone->lru_lock);
 			pgdeactivate += pgmoved;
 			pgmoved = 0;
@@ -1208,7 +1127,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 			spin_lock_irq(&zone->lru_lock);
 		}
 	}
-	__mod_zone_page_state(zone, NR_INACTIVE, pgmoved);
+	__mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
 	pgdeactivate += pgmoved;
 	if (buffer_heads_over_limit) {
 		spin_unlock_irq(&zone->lru_lock);
@@ -1217,6 +1136,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 	}
 
 	pgmoved = 0;
+	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);
@@ -1224,11 +1144,11 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 		SetPageLRU(page);
 		VM_BUG_ON(!PageActive(page));
 
-		list_move(&page->lru, &zone->lru[LRU_ACTIVE].list);
+		list_move(&page->lru, &zone->lru[lru].list);
 		mem_cgroup_move_lists(page, true);
 		pgmoved++;
 		if (!pagevec_add(&pvec, page)) {
-			__mod_zone_page_state(zone, NR_ACTIVE, pgmoved);
+			__mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
 			pgmoved = 0;
 			spin_unlock_irq(&zone->lru_lock);
 			if (vm_swap_full())
@@ -1237,7 +1157,8 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 			spin_lock_irq(&zone->lru_lock);
 		}
 	}
-	__mod_zone_page_state(zone, NR_ACTIVE, pgmoved);
+	__mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
+	zone->recent_rotated[!!file] += pgmoved;
 
 	__count_zone_vm_events(PGREFILL, zone, pgscanned);
 	__count_vm_events(PGDEACTIVATE, pgdeactivate);
@@ -1248,16 +1169,103 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 	pagevec_release(&pvec);
 }
 
-static unsigned long shrink_list(enum lru_list l, unsigned long nr_to_scan,
+static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan,
 	struct zone *zone, struct scan_control *sc, int priority)
 {
-	if (l == LRU_ACTIVE) {
-		shrink_active_list(nr_to_scan, zone, sc, priority);
+	int file = is_file_lru(lru);
+
+	if (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE) {
+		shrink_active_list(nr_to_scan, zone, sc, priority, file);
 		return 0;
 	}
-	return shrink_inactive_list(nr_to_scan, zone, sc);
+	return shrink_inactive_list(nr_to_scan, zone, sc, file);
+}
+
+/*
+ * Determine how aggressively the anon and file LRU lists should be
+ * scanned.  The relative value of each set of LRU lists is determined
+ * by looking at the fraction of the pages scanned we did rotate back
+ * onto the active list instead of evict.
+ *
+ * percent[0] specifies how much pressure to put on ram/swap backed
+ * memory, while percent[1] determines pressure on the file LRUs.
+ */
+static void get_scan_ratio(struct zone *zone, struct scan_control *sc,
+					unsigned long *percent)
+{
+	unsigned long anon, file, free;
+	unsigned long anon_prio, file_prio;
+	unsigned long ap, fp;
+
+	anon  = zone_page_state(zone, NR_ACTIVE_ANON) +
+		zone_page_state(zone, NR_INACTIVE_ANON);
+	file  = zone_page_state(zone, NR_ACTIVE_FILE) +
+		zone_page_state(zone, NR_INACTIVE_FILE);
+	free  = zone_page_state(zone, NR_FREE_PAGES);
+
+	/* If we have no swap space, do not bother scanning anon pages. */
+	if (nr_swap_pages <= 0) {
+		percent[0] = 0;
+		percent[1] = 100;
+		return;
+	}
+
+	/* If we have very few page cache pages, force-scan anon pages. */
+	if (unlikely(file + free <= zone->pages_high)) {
+		percent[0] = 100;
+		percent[1] = 0;
+		return;
+	}
+
+	/*
+	 * OK, so we have swap space and a fair amount of page cache
+	 * pages.  We use the recently rotated / recently scanned
+	 * ratios to determine how valuable each cache is.
+	 *
+	 * Because workloads change over time (and to avoid overflow)
+	 * we keep these statistics as a floating average, which ends
+	 * up weighing recent references more than old ones.
+	 *
+	 * anon in [0], file in [1]
+	 */
+	if (unlikely(zone->recent_scanned[0] > anon / 4)) {
+		spin_lock_irq(&zone->lru_lock);
+		zone->recent_scanned[0] /= 2;
+		zone->recent_rotated[0] /= 2;
+		spin_unlock_irq(&zone->lru_lock);
+	}
+
+	if (unlikely(zone->recent_scanned[1] > file / 4)) {
+		spin_lock_irq(&zone->lru_lock);
+		zone->recent_scanned[1] /= 2;
+		zone->recent_rotated[1] /= 2;
+		spin_unlock_irq(&zone->lru_lock);
+	}
+
+	/*
+	 * With swappiness at 100, anonymous and file have the same priority.
+	 * This scanning priority is essentially the inverse of IO cost.
+	 */
+	anon_prio = sc->swappiness;
+	file_prio = 200 - sc->swappiness;
+
+	/*
+	 *                  anon       recent_rotated[0]
+	 * %anon = 100 * ----------- / ----------------- * IO cost
+	 *               anon + file      rotate_sum
+	 */
+	ap = (anon_prio + 1) * (zone->recent_scanned[0] + 1);
+	ap /= zone->recent_rotated[0] + 1;
+
+	fp = (file_prio + 1) * (zone->recent_scanned[1] + 1);
+	fp /= zone->recent_rotated[1] + 1;
+
+	/* Normalize to percentages */
+	percent[0] = 100 * ap / (ap + fp + 1);
+	percent[1] = 100 - percent[0];
 }
 
+
 /*
  * This is a basic per-zone page freer.  Used by both kswapd and direct reclaim.
  */
@@ -1267,36 +1275,43 @@ static unsigned long shrink_zone(int priority, struct zone *zone,
 	unsigned long nr[NR_LRU_LISTS];
 	unsigned long nr_to_scan;
 	unsigned long nr_reclaimed = 0;
+	unsigned long percent[2];	/* anon @ 0; file @ 1 */
 	enum lru_list l;
 
-	if (scan_global_lru(sc)) {
-		/*
-		 * Add one to nr_to_scan just to make sure that the kernel
-		 * will slowly sift through the active list.
-		 */
-		for_each_lru(l) {
-			zone->lru[l].nr_scan += (zone_page_state(zone,
-					NR_LRU_BASE + l)  >> priority) + 1;
+	get_scan_ratio(zone, sc, percent);
+
+	for_each_lru(l) {
+		if (scan_global_lru(sc)) {
+			int file = is_file_lru(l);
+			int scan;
+			/*
+			 * Add one to nr_to_scan just to make sure that the
+			 * kernel will slowly sift through each list.
+			 */
+			scan = zone_page_state(zone, NR_LRU_BASE + l);
+			if (priority) {
+				scan >>= priority;
+				scan = (scan * percent[file]) / 100;
+			}
+			zone->lru[l].nr_scan += scan + 1;
 			nr[l] = zone->lru[l].nr_scan;
 			if (nr[l] >= sc->swap_cluster_max)
 				zone->lru[l].nr_scan = 0;
 			else
 				nr[l] = 0;
+		} else {
+			/*
+			 * This reclaim occurs not because zone memory shortage
+			 * but because memory controller hits its limit.
+			 * Don't modify zone reclaim related data.
+			 */
+			nr[l] = mem_cgroup_calc_reclaim(sc->mem_cgroup, zone,
+								priority, l);
 		}
-	} else {
-		/*
-		 * This reclaim occurs not because zone memory shortage but
-		 * because memory controller hits its limit.
-		 * Then, don't modify zone reclaim related data.
-		 */
-		nr[LRU_ACTIVE] = mem_cgroup_calc_reclaim(sc->mem_cgroup,
-					zone, priority, LRU_ACTIVE);
-
-		nr[LRU_INACTIVE] = mem_cgroup_calc_reclaim(sc->mem_cgroup,
-					zone, priority, LRU_INACTIVE);
 	}
 
-	while (nr[LRU_ACTIVE] || nr[LRU_INACTIVE]) {
+	while (nr[LRU_ACTIVE_ANON] || nr[LRU_INACTIVE_ANON] ||
+			nr[LRU_ACTIVE_FILE] || nr[LRU_INACTIVE_FILE]) {
 		for_each_lru(l) {
 			if (nr[l]) {
 				nr_to_scan = min(nr[l],
@@ -1369,7 +1384,7 @@ static unsigned long shrink_zones(int priority, struct zonelist *zonelist,
 
 	return nr_reclaimed;
 }
- 
+
 /*
  * This is the main entry point to direct page reclaim.
  *
@@ -1412,8 +1427,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 			if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
 				continue;
 
-			lru_pages += zone_page_state(zone, NR_ACTIVE)
-					+ zone_page_state(zone, NR_INACTIVE);
+			lru_pages += zone_lru_pages(zone);
 		}
 	}
 
@@ -1615,8 +1629,7 @@ loop_again:
 		for (i = 0; i <= end_zone; i++) {
 			struct zone *zone = pgdat->node_zones + i;
 
-			lru_pages += zone_page_state(zone, NR_ACTIVE)
-					+ zone_page_state(zone, NR_INACTIVE);
+			lru_pages += zone_lru_pages(zone);
 		}
 
 		/*
@@ -1660,8 +1673,7 @@ loop_again:
 			if (zone_is_all_unreclaimable(zone))
 				continue;
 			if (nr_slab == 0 && zone->pages_scanned >=
-				(zone_page_state(zone, NR_ACTIVE)
-				+ zone_page_state(zone, NR_INACTIVE)) * 6)
+						(zone_lru_pages(zone) * 6))
 					zone_set_flag(zone,
 						      ZONE_ALL_UNRECLAIMABLE);
 			/*
@@ -1715,7 +1727,7 @@ out:
 
 /*
  * The background pageout daemon, started as a kernel thread
- * from the init process. 
+ * from the init process.
  *
  * This basically trickles out pages so that we have _some_
  * free memory available even if there is no other activity
@@ -1809,6 +1821,14 @@ void wakeup_kswapd(struct zone *zone, int order)
 	wake_up_interruptible(&pgdat->kswapd_wait);
 }
 
+unsigned long global_lru_pages(void)
+{
+	return global_page_state(NR_ACTIVE_ANON)
+		+ global_page_state(NR_ACTIVE_FILE)
+		+ global_page_state(NR_INACTIVE_ANON)
+		+ global_page_state(NR_INACTIVE_FILE);
+}
+
 #ifdef CONFIG_PM
 /*
  * Helper function for shrink_all_memory().  Tries to reclaim 'nr_pages' pages
@@ -1834,7 +1854,8 @@ static unsigned long shrink_all_zones(unsigned long nr_pages, int prio,
 
 		for_each_lru(l) {
 			/* For pass = 0 we don't shrink the active list */
-			if (pass == 0 && l == LRU_ACTIVE)
+			if (pass == 0 &&
+				(l == LRU_ACTIVE || l == LRU_ACTIVE_FILE))
 				continue;
 
 			zone->lru[l].nr_scan +=
@@ -1856,11 +1877,6 @@ static unsigned long shrink_all_zones(unsigned long nr_pages, int prio,
 	return ret;
 }
 
-static unsigned long count_lru_pages(void)
-{
-	return global_page_state(NR_ACTIVE) + global_page_state(NR_INACTIVE);
-}
-
 /*
  * Try to free `nr_pages' of memory, system-wide, and return the number of
  * freed pages.
@@ -1886,7 +1902,7 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
 
 	current->reclaim_state = &reclaim_state;
 
-	lru_pages = count_lru_pages();
+	lru_pages = global_lru_pages();
 	nr_slab = global_page_state(NR_SLAB_RECLAIMABLE);
 	/* If slab caches are huge, it's better to hit them first */
 	while (nr_slab >= lru_pages) {
@@ -1929,7 +1945,7 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
 
 			reclaim_state.reclaimed_slab = 0;
 			shrink_slab(sc.nr_scanned, sc.gfp_mask,
-					count_lru_pages());
+					global_lru_pages());
 			ret += reclaim_state.reclaimed_slab;
 			if (ret >= nr_pages)
 				goto out;
@@ -1946,7 +1962,7 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
 	if (!ret) {
 		do {
 			reclaim_state.reclaimed_slab = 0;
-			shrink_slab(nr_pages, sc.gfp_mask, count_lru_pages());
+			shrink_slab(nr_pages, sc.gfp_mask, global_lru_pages());
 			ret += reclaim_state.reclaimed_slab;
 		} while (ret < nr_pages && reclaim_state.reclaimed_slab > 0);
 	}