1 files changed, 19 insertions, 1 deletions

diff --git a/mm/compaction.c b/mm/compaction.c
index e5995f38d677..cd93ea24c565 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1438,6 +1438,11 @@ bool compaction_zonelist_suitable(struct alloc_context *ac, int order,
 {
         struct zone *zone;
         struct zoneref *z;
+        pg_data_t *last_pgdat = NULL;
+
+        /* Do not retry compaction for zone-constrained allocations */
+        if (ac->high_zoneidx < ZONE_NORMAL)
+                return false;
 
         /*
          * Make sure at least one zone would pass __compaction_suitable if we continue
@@ -1448,14 +1453,27 @@ bool compaction_zonelist_suitable(struct alloc_context *ac, int order,
                 unsigned long available;
                 enum compact_result compact_result;
 
+                if (last_pgdat == zone->zone_pgdat)
+                        continue;
+
+                /*
+                 * This over-estimates the number of pages available for
+                 * reclaim/compaction but walking the LRU would take too
+                 * long. The consequences are that compaction may retry
+                 * longer than it should for a zone-constrained allocation
+                 * request.
+                 */
+                last_pgdat = zone->zone_pgdat;
+                available = pgdat_reclaimable_pages(zone->zone_pgdat) / order;
+
                 /*
                  * 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);
+                available = min(zone->managed_pages, available);
                 compact_result = __compaction_suitable(zone, order, alloc_flags,
                                 ac_classzone_idx(ac), available);
                 if (compact_result != COMPACT_SKIPPED &&