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-rw-r--r--mm/vmscan.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 5daf606e0a35..b07c48b09a93 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1867,6 +1867,23 @@ out:
 
 		try_to_freeze();
 
+		/*
+		 * Fragmentation may mean that the system cannot be
+		 * rebalanced for high-order allocations in all zones.
+		 * At this point, if nr_reclaimed < SWAP_CLUSTER_MAX,
+		 * it means the zones have been fully scanned and are still
+		 * not balanced. For high-order allocations, there is
+		 * little point trying all over again as kswapd may
+		 * infinite loop.
+		 *
+		 * Instead, recheck all watermarks at order-0 as they
+		 * are the most important. If watermarks are ok, kswapd will go
+		 * back to sleep. High-order users can still perform direct
+		 * reclaim if they wish.
+		 */
+		if (sc.nr_reclaimed < SWAP_CLUSTER_MAX)
+			order = sc.order = 0;
+
 		goto loop_again;
 	}