cma: count free CMA pages

Add NR_FREE_CMA_PAGES counter to be later used for checking watermark in
__zone_watermark_ok().  For simplicity and to avoid #ifdef hell make this
counter always available (not only when CONFIG_CMA=y).

[akpm@linux-foundation.org: use conventional migratetype naming]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d259cc2..6969a8a 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -558,7 +558,8 @@
 		if (page_is_guard(buddy)) {
 			clear_page_guard_flag(buddy);
 			set_page_private(page, 0);
-			__mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
+			__mod_zone_freepage_state(zone, 1 << order,
+						  migratetype);
 		} else {
 			list_del(&buddy->lru);
 			zone->free_area[order].nr_free--;
@@ -677,6 +678,8 @@
 			/* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
 			__free_one_page(page, zone, 0, mt);
 			trace_mm_page_pcpu_drain(page, 0, mt);
+			if (is_migrate_cma(mt))
+				__mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1);
 		} while (--to_free && --batch_free && !list_empty(list));
 	}
 	__mod_zone_page_state(zone, NR_FREE_PAGES, count);
@@ -692,7 +695,7 @@
 
 	__free_one_page(page, zone, order, migratetype);
 	if (unlikely(migratetype != MIGRATE_ISOLATE))
-		__mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
+		__mod_zone_freepage_state(zone, 1 << order, migratetype);
 	spin_unlock(&zone->lock);
 }
 
@@ -815,7 +818,8 @@
 			set_page_guard_flag(&page[size]);
 			set_page_private(&page[size], high);
 			/* Guard pages are not available for any usage */
-			__mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << high));
+			__mod_zone_freepage_state(zone, -(1 << high),
+						  migratetype);
 			continue;
 		}
 #endif
@@ -1141,6 +1145,9 @@
 		}
 		set_page_private(page, mt);
 		list = &page->lru;
+		if (is_migrate_cma(mt))
+			__mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
+					      -(1 << order));
 	}
 	__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
 	spin_unlock(&zone->lock);
@@ -1412,7 +1419,7 @@
 
 	mt = get_pageblock_migratetype(page);
 	if (unlikely(mt != MIGRATE_ISOLATE))
-		__mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order));
+		__mod_zone_freepage_state(zone, -(1UL << order), mt);
 
 	if (alloc_order != order)
 		expand(zone, page, alloc_order, order,
@@ -1516,7 +1523,8 @@
 		spin_unlock(&zone->lock);
 		if (!page)
 			goto failed;
-		__mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
+		__mod_zone_freepage_state(zone, -(1 << order),
+					  get_pageblock_migratetype(page));
 	}
 
 	__count_zone_vm_events(PGALLOC, zone, 1 << order);
@@ -2890,7 +2898,8 @@
 		" unevictable:%lu"
 		" dirty:%lu writeback:%lu unstable:%lu\n"
 		" free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
-		" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
+		" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
+		" free_cma:%lu\n",
 		global_page_state(NR_ACTIVE_ANON),
 		global_page_state(NR_INACTIVE_ANON),
 		global_page_state(NR_ISOLATED_ANON),
@@ -2907,7 +2916,8 @@
 		global_page_state(NR_FILE_MAPPED),
 		global_page_state(NR_SHMEM),
 		global_page_state(NR_PAGETABLE),
-		global_page_state(NR_BOUNCE));
+		global_page_state(NR_BOUNCE),
+		global_page_state(NR_FREE_CMA_PAGES));
 
 	for_each_populated_zone(zone) {
 		int i;
@@ -2939,6 +2949,7 @@
 			" pagetables:%lukB"
 			" unstable:%lukB"
 			" bounce:%lukB"
+			" free_cma:%lukB"
 			" writeback_tmp:%lukB"
 			" pages_scanned:%lu"
 			" all_unreclaimable? %s"
@@ -2968,6 +2979,7 @@
 			K(zone_page_state(zone, NR_PAGETABLE)),
 			K(zone_page_state(zone, NR_UNSTABLE_NFS)),
 			K(zone_page_state(zone, NR_BOUNCE)),
+			K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
 			K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
 			zone->pages_scanned,
 			(zone->all_unreclaimable ? "yes" : "no")