cma: fix watermark checking

* Add ALLOC_CMA alloc flag and pass it to [__]zone_watermark_ok()
  (from Minchan Kim).

* During watermark check decrease available free pages number by
  free CMA pages number if necessary (unmovable allocations cannot
  use pages from CMA areas).

CRs-Fixed: 446321
Change-Id: Ibd069b028eb80b70701c1b81cb28a503d8265be0
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>
[lauraa@codeaurora.org: context fixups]
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
diff --git a/mm/compaction.c b/mm/compaction.c
index da7d35e..353f1c5 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -750,6 +750,7 @@
 	struct zoneref *z;
 	struct zone *zone;
 	int rc = COMPACT_SKIPPED;
+	int alloc_flags = 0;
 
 	/*
 	 * Check whether it is worth even starting compaction. The order check is
@@ -761,6 +762,10 @@
 
 	count_vm_event(COMPACTSTALL);
 
+#ifdef CONFIG_CMA
+	if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
+		alloc_flags |= ALLOC_CMA;
+#endif
 	/* Compact each zone in the list */
 	for_each_zone_zonelist_nodemask(zone, z, zonelist, high_zoneidx,
 								nodemask) {
@@ -770,7 +775,8 @@
 		rc = max(status, rc);
 
 		/* If a normal allocation would succeed, stop compacting */
-		if (zone_watermark_ok(zone, order, low_wmark_pages(zone), 0, 0))
+		if (zone_watermark_ok(zone, order, low_wmark_pages(zone), 0,
+				      alloc_flags))
 			break;
 	}
 
diff --git a/mm/internal.h b/mm/internal.h
index aee4761..8c6fd44 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -342,3 +342,17 @@
 extern u64 hwpoison_filter_flags_value;
 extern u64 hwpoison_filter_memcg;
 extern u32 hwpoison_filter_enable;
+
+/* The ALLOC_WMARK bits are used as an index to zone->watermark */
+#define ALLOC_WMARK_MIN		WMARK_MIN
+#define ALLOC_WMARK_LOW		WMARK_LOW
+#define ALLOC_WMARK_HIGH	WMARK_HIGH
+#define ALLOC_NO_WATERMARKS	0x04 /* don't check watermarks at all */
+
+/* Mask to get the watermark bits */
+#define ALLOC_WMARK_MASK	(ALLOC_NO_WATERMARKS-1)
+
+#define ALLOC_HARDER		0x10 /* try to alloc harder */
+#define ALLOC_HIGH		0x20 /* __GFP_HIGH set */
+#define ALLOC_CPUSET		0x40 /* check for correct cpuset */
+#define ALLOC_CMA		0x80 /* allow allocations from CMA areas */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 73ac1b0..6e42cc2 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1524,19 +1524,6 @@
 	return NULL;
 }
 
-/* The ALLOC_WMARK bits are used as an index to zone->watermark */
-#define ALLOC_WMARK_MIN		WMARK_MIN
-#define ALLOC_WMARK_LOW		WMARK_LOW
-#define ALLOC_WMARK_HIGH	WMARK_HIGH
-#define ALLOC_NO_WATERMARKS	0x04 /* don't check watermarks at all */
-
-/* Mask to get the watermark bits */
-#define ALLOC_WMARK_MASK	(ALLOC_NO_WATERMARKS-1)
-
-#define ALLOC_HARDER		0x10 /* try to alloc harder */
-#define ALLOC_HIGH		0x20 /* __GFP_HIGH set */
-#define ALLOC_CPUSET		0x40 /* check for correct cpuset */
-
 #ifdef CONFIG_FAIL_PAGE_ALLOC
 
 static struct {
@@ -1631,7 +1618,11 @@
 		min -= min / 2;
 	if (alloc_flags & ALLOC_HARDER)
 		min -= min / 4;
-
+#ifdef CONFIG_CMA
+	/* If allocation can't use CMA areas don't use free CMA pages */
+	if (!(alloc_flags & ALLOC_CMA))
+		free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
+#endif
 	if (free_pages <= min + lowmem_reserve)
 		return false;
 	for (o = 0; o < order; o++) {
@@ -2300,7 +2291,10 @@
 		     unlikely(test_thread_flag(TIF_MEMDIE))))
 			alloc_flags |= ALLOC_NO_WATERMARKS;
 	}
-
+#ifdef CONFIG_CMA
+	if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
+		alloc_flags |= ALLOC_CMA;
+#endif
 	return alloc_flags;
 }
 
@@ -2509,6 +2503,7 @@
 	struct page *page = NULL;
 	int migratetype = allocflags_to_migratetype(gfp_mask);
 	unsigned int cpuset_mems_cookie;
+	int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET;
 
 	gfp_mask &= gfp_allowed_mask;
 
@@ -2537,9 +2532,13 @@
 	if (!preferred_zone)
 		goto out;
 
+#ifdef CONFIG_CMA
+	if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
+		alloc_flags |= ALLOC_CMA;
+#endif
 	/* First allocation attempt */
 	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
-			zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
+			zonelist, high_zoneidx, alloc_flags,
 			preferred_zone, migratetype);
 	if (unlikely(!page))
 		page = __alloc_pages_slowpath(gfp_mask, order,