vmscan: one cleanup, one bugfix

@@ -2048,16 +2048,14 @@ unsigned long global_lru_pages(void)
 #ifdef CONFIG_PM
 /*
  * Helper function for shrink_all_memory().  Tries to reclaim 'nr_pages' pages
- * from LRU lists system-wide, for given pass and priority, and returns the
- * number of reclaimed pages
+ * from LRU lists system-wide, for given pass and priority.
  *
  * For pass > 3 we also try to shrink the LRU lists that contain a few pages
  */
-static unsigned long shrink_all_zones(unsigned long nr_pages, int prio,
-				      int pass, struct scan_control *sc)
+static void shrink_all_zones(unsigned long nr_pages, int prio,
+			      int pass, struct scan_control *sc)
 {
 	struct zone *zone;
-	unsigned long ret = 0;
 
 	for_each_zone(zone) {
 		enum lru_list l;

@@ -2082,14 +2080,13 @@ static unsigned long shrink_all_zones(un
 
 				zone->lru[l].nr_scan = 0;
 				nr_to_scan = min(nr_pages, lru_pages);
-				ret += shrink_list(l, nr_to_scan, zone,
-								sc, prio);
-				if (ret >= nr_pages)
-					return ret;
+				sc->nr_reclaimed += shrink_list(l, nr_to_scan,
+								zone, sc, prio);
+				if (sc->nr_reclaimed >= nr_pages)
+					return;
 			}
 		}
 	}
-	return ret;
 }
 
 /*

@@ -2103,7 +2100,6 @@ static unsigned long shrink_all_zones(un
 unsigned long shrink_all_memory(unsigned long nr_pages)
 {
 	unsigned long lru_pages, nr_slab;
-	unsigned long ret = 0;
 	int pass;
 	struct reclaim_state reclaim_state;
 	struct scan_control sc = {

@@ -2125,8 +2121,8 @@ unsigned long shrink_all_memory(unsigned
 		if (!reclaim_state.reclaimed_slab)
 			break;
 
-		ret += reclaim_state.reclaimed_slab;
-		if (ret >= nr_pages)
+		sc.nr_reclaimed += reclaim_state.reclaimed_slab;
+		if (sc.nr_reclaimed >= nr_pages)
 			goto out;
 
 		nr_slab -= reclaim_state.reclaimed_slab;

@@ -2148,18 +2144,18 @@ unsigned long shrink_all_memory(unsigned
 			sc.may_unmap = 1;
 
 		for (prio = DEF_PRIORITY; prio >= 0; prio--) {
-			unsigned long nr_to_scan = nr_pages - ret;
+			unsigned long nr_to_scan = nr_pages - sc.nr_reclaimed;
 
 			sc.nr_scanned = 0;
-			ret += shrink_all_zones(nr_to_scan, prio, pass, &sc);
-			if (ret >= nr_pages)
+			shrink_all_zones(nr_to_scan, prio, pass, &sc);
+			if (sc.nr_reclaimed >= nr_pages)
 				goto out;
 
 			reclaim_state.reclaimed_slab = 0;
 			shrink_slab(sc.nr_scanned, sc.gfp_mask,
 					global_lru_pages());
-			ret += reclaim_state.reclaimed_slab;
-			if (ret >= nr_pages)
+			sc.nr_reclaimed += reclaim_state.reclaimed_slab;
+			if (sc.nr_reclaimed >= nr_pages)
 				goto out;
 
 			if (sc.nr_scanned && prio < DEF_PRIORITY - 2)

@@ -2167,22 +2163,23 @@ unsigned long shrink_all_memory(unsigned
 		}
 	}
 
-	/*
-	 * If ret = 0, we could not shrink LRUs, but there may be something
-	 * in slab caches
-	 */
-	if (!ret) {
+	if (!sc.nr_reclaimed) {
+		/*
+		 * We could not shrink LRUs, but there may be something
+		 * in slab caches.
+		 */
 		do {
 			reclaim_state.reclaimed_slab = 0;
 			shrink_slab(nr_pages, sc.gfp_mask, global_lru_pages());
-			ret += reclaim_state.reclaimed_slab;
-		} while (ret < nr_pages && reclaim_state.reclaimed_slab > 0);
+			sc.nr_reclaimed += reclaim_state.reclaimed_slab;
+		} while (sc.nr_reclaimed < nr_pages &&
+				reclaim_state.reclaimed_slab > 0);
 	}
 
 out:
 	current->reclaim_state = NULL;
 
-	return ret;
+	return sc.nr_reclaimed;
 }
 #endif
 

@@ -2105,7 +2105,6 @@ unsigned long shrink_all_memory(unsigned
 	struct scan_control sc = {
 		.gfp_mask = GFP_KERNEL,
 		.may_unmap = 0,
-		.swap_cluster_max = nr_pages,
 		.may_writepage = 1,
 		.isolate_pages = isolate_pages_global,
 	};

@@ -2147,6 +2146,7 @@ unsigned long shrink_all_memory(unsigned
 			unsigned long nr_to_scan = nr_pages - sc.nr_reclaimed;
 
 			sc.nr_scanned = 0;
+			sc.swap_cluster_max = nr_to_scan;
 			shrink_all_zones(nr_to_scan, prio, pass, &sc);
 			if (sc.nr_reclaimed >= nr_pages)
 				goto out;