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).

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>

1 files changed, 7 insertions, 1 deletions

diff --git a/mm/compaction.c b/mm/compaction.c
index 0fbc6b73a522..1f61bcbd6262 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -934,6 +934,7 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
         struct zoneref *z;
         struct zone *zone;
         int rc = COMPACT_SKIPPED;
+        int alloc_flags = 0;
 
         /* Check if the GFP flags allow compaction */
         if (!order || !may_enter_fs || !may_perform_io)
@@ -941,6 +942,10 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
 
         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) {
@@ -951,7 +956,8 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
                 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;
         }