1 files changed, 39 insertions, 3 deletions

diff --git a/mm/compaction.c b/mm/compaction.c
index 4af1577adb5c..d8a20fcf8678 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1318,7 +1318,8 @@ static enum compact_result compact_finished(struct zone *zone,
  */
 static enum compact_result __compaction_suitable(struct zone *zone, int order,
                                         unsigned int alloc_flags,
-                                        int classzone_idx)
+                                        int classzone_idx,
+                                        unsigned long wmark_target)
 {
         int fragindex;
         unsigned long watermark;
@@ -1341,7 +1342,8 @@ static enum compact_result __compaction_suitable(struct zone *zone, int order,
          * allocated and for a short time, the footprint is higher
          */
         watermark += (2UL << order);
-        if (!zone_watermark_ok(zone, 0, watermark, classzone_idx, alloc_flags))
+        if (!__zone_watermark_ok(zone, 0, watermark, classzone_idx,
+                                 alloc_flags, wmark_target))
                 return COMPACT_SKIPPED;
 
         /*
@@ -1368,7 +1370,8 @@ enum compact_result compaction_suitable(struct zone *zone, int order,
 {
         enum compact_result ret;
 
-        ret = __compaction_suitable(zone, order, alloc_flags, classzone_idx);
+        ret = __compaction_suitable(zone, order, alloc_flags, classzone_idx,
+                                    zone_page_state(zone, NR_FREE_PAGES));
         trace_mm_compaction_suitable(zone, order, ret);
         if (ret == COMPACT_NOT_SUITABLE_ZONE)
                 ret = COMPACT_SKIPPED;
@@ -1376,6 +1379,39 @@ enum compact_result compaction_suitable(struct zone *zone, int order,
         return ret;
 }
 
+bool compaction_zonelist_suitable(struct alloc_context *ac, int order,
+                int alloc_flags)
+{
+        struct zone *zone;
+        struct zoneref *z;
+
+        /*
+         * Make sure at least one zone would pass __compaction_suitable if we continue
+         * retrying the reclaim.
+         */
+        for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
+                                        ac->nodemask) {
+                unsigned long available;
+                enum compact_result compact_result;
+
+                /*
+                 * Do not consider all the reclaimable memory because we do not
+                 * want to trash just for a single high order allocation which
+                 * is even not guaranteed to appear even if __compaction_suitable
+                 * is happy about the watermark check.
+                 */
+                available = zone_reclaimable_pages(zone) / order;
+                available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
+                compact_result = __compaction_suitable(zone, order, alloc_flags,
+                                ac_classzone_idx(ac), available);
+                if (compact_result != COMPACT_SKIPPED &&
+                                compact_result != COMPACT_NOT_SUITABLE_ZONE)
+                        return true;
+        }
+
+        return false;
+}
+
 static enum compact_result compact_zone(struct zone *zone, struct compact_control *cc)
 {
         enum compact_result ret;