mm/vmscan: remove update_isolated_counts()

update_isolated_counts() is no longer required, because lumpy-reclaim was
removed.  Insanity is over, now there is only one kind of inactive page.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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>

mm/vmscan.c

@@ -1205,52 +1205,6 @@ putback_inactive_pages(struct mem_cgroup_zone *mz,
 	list_splice(&pages_to_free, page_list);
 }
 
-static noinline_for_stack void
-update_isolated_counts(struct mem_cgroup_zone *mz,
-		       struct list_head *page_list,
-		       unsigned long *nr_anon,
-		       unsigned long *nr_file)
-{
-	struct zone *zone = mz->zone;
-	unsigned int count[NR_LRU_LISTS] = { 0, };
-	unsigned long nr_active = 0;
-	struct page *page;
-	int lru;
-
-	/*
-	 * Count pages and clear active flags
-	 */
-	list_for_each_entry(page, page_list, lru) {
-		int numpages = hpage_nr_pages(page);
-		lru = page_lru_base_type(page);
-		if (PageActive(page)) {
-			lru += LRU_ACTIVE;
-			ClearPageActive(page);
-			nr_active += numpages;
-		}
-		count[lru] += numpages;
-	}
-
-	preempt_disable();
-	__count_vm_events(PGDEACTIVATE, nr_active);
-
-	__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]);
-
-	*nr_anon = count[LRU_ACTIVE_ANON] + count[LRU_INACTIVE_ANON];
-	*nr_file = count[LRU_ACTIVE_FILE] + count[LRU_INACTIVE_FILE];
-
-	__mod_zone_page_state(zone, NR_ISOLATED_ANON, *nr_anon);
-	__mod_zone_page_state(zone, NR_ISOLATED_FILE, *nr_file);
-	preempt_enable();
-}
-
 /*
  * shrink_inactive_list() is a helper for shrink_zone().  It returns the number
  * of reclaimed pages
@@ -1263,8 +1217,6 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
 	unsigned long nr_scanned;
 	unsigned long nr_reclaimed = 0;
 	unsigned long nr_taken;
-	unsigned long nr_anon;
-	unsigned long nr_file;
 	unsigned long nr_dirty = 0;
 	unsigned long nr_writeback = 0;
 	isolate_mode_t isolate_mode = 0;
@@ -1292,6 +1244,10 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
 
 	nr_taken = isolate_lru_pages(nr_to_scan, lruvec, &page_list,
 				     &nr_scanned, sc, isolate_mode, lru);
+
+	__mod_zone_page_state(zone, NR_LRU_BASE + lru, -nr_taken);
+	__mod_zone_page_state(zone, NR_ISOLATED_ANON + file, nr_taken);
+
 	if (global_reclaim(sc)) {
 		zone->pages_scanned += nr_scanned;
 		if (current_is_kswapd())
@@ -1306,15 +1262,12 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
 	if (nr_taken == 0)
 		return 0;
 
-	update_isolated_counts(mz, &page_list, &nr_anon, &nr_file);
-
 	nr_reclaimed = shrink_page_list(&page_list, zone, sc,
 						&nr_dirty, &nr_writeback);
 
 	spin_lock_irq(&zone->lru_lock);
 
-	reclaim_stat->recent_scanned[0] += nr_anon;
-	reclaim_stat->recent_scanned[1] += nr_file;
+	reclaim_stat->recent_scanned[file] += nr_taken;
 
 	if (global_reclaim(sc)) {
 		if (current_is_kswapd())
@@ -1327,8 +1280,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
 
 	putback_inactive_pages(mz, &page_list);
 
-	__mod_zone_page_state(zone, NR_ISOLATED_ANON, -nr_anon);
-	__mod_zone_page_state(zone, NR_ISOLATED_FILE, -nr_file);
+	__mod_zone_page_state(zone, NR_ISOLATED_ANON + file, -nr_taken);
 
 	spin_unlock_irq(&zone->lru_lock);