---

yaml
---
r: 347345
b: refs/heads/master
c: cda73a1
h: refs/heads/master
i:
  347343: 4dec3a8
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: f01af9f85855e38fbd601e033a8eac204cc4cc1c
+refs/heads/master: cda73a10eb3f493871ed39f468db50a65ebeddce

trunk/mm/vmscan.c

@@ -2570,7 +2570,7 @@ static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, long remaining,
 static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
 							int *classzone_idx)
 {
-	int all_zones_ok;
+	struct zone *unbalanced_zone;
 	unsigned long balanced;
 	int i;
 	int end_zone = 0;	/* Inclusive.  0 = ZONE_DMA */
@@ -2604,7 +2604,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
 		unsigned long lru_pages = 0;
 		int has_under_min_watermark_zone = 0;
 
-		all_zones_ok = 1;
+		unbalanced_zone = NULL;
 		balanced = 0;
 
 		/*
@@ -2743,7 +2743,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
 			}
 
 			if (!zone_balanced(zone, testorder, 0, end_zone)) {
-				all_zones_ok = 0;
+				unbalanced_zone = zone;
 				/*
 				 * We are still under min water mark.  This
 				 * means that we have a GFP_ATOMIC allocation
@@ -2776,7 +2776,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
 				pfmemalloc_watermark_ok(pgdat))
 			wake_up(&pgdat->pfmemalloc_wait);
 
-		if (all_zones_ok || (order && pgdat_balanced(pgdat, balanced, *classzone_idx)))
+		if (!unbalanced_zone || (order && pgdat_balanced(pgdat, balanced, *classzone_idx)))
 			break;		/* kswapd: all done */
 		/*
 		 * OK, kswapd is getting into trouble.  Take a nap, then take
@@ -2786,7 +2786,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
 			if (has_under_min_watermark_zone)
 				count_vm_event(KSWAPD_SKIP_CONGESTION_WAIT);
 			else
-				congestion_wait(BLK_RW_ASYNC, HZ/10);
+				wait_iff_congested(unbalanced_zone, BLK_RW_ASYNC, HZ/10);
 		}
 
 		/*
@@ -2805,7 +2805,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
 	 * high-order: Balanced zones must make up at least 25% of the node
 	 *             for the node to be balanced
 	 */
-	if (!(all_zones_ok || (order && pgdat_balanced(pgdat, balanced, *classzone_idx)))) {
+	if (unbalanced_zone && (!order || !pgdat_balanced(pgdat, balanced, *classzone_idx))) {
 		cond_resched();
 
 		try_to_freeze();