1 files changed, 24 insertions, 5 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 2813054..b0cd81c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -201,13 +201,25 @@ static int shrink_slab(unsigned long scanned, gfp_t gfp_mask,
 	list_for_each_entry(shrinker, &shrinker_list, list) {
 		unsigned long long delta;
 		unsigned long total_scan;
+		unsigned long max_pass = (*shrinker->shrinker)(0, gfp_mask);
 
 		delta = (4 * scanned) / shrinker->seeks;
-		delta *= (*shrinker->shrinker)(0, gfp_mask);
+		delta *= max_pass;
 		do_div(delta, lru_pages + 1);
 		shrinker->nr += delta;
-		if (shrinker->nr < 0)
-			shrinker->nr = LONG_MAX;	/* It wrapped! */
+		if (shrinker->nr < 0) {
+			printk(KERN_ERR "%s: nr=%ld\n",
+					__FUNCTION__, shrinker->nr);
+			shrinker->nr = max_pass;
+		}
+
+		/*
+		 * Avoid risking looping forever due to too large nr value:
+		 * never try to free more than twice the estimate number of
+		 * freeable entries.
+		 */
+		if (shrinker->nr > max_pass * 2)
+			shrinker->nr = max_pass * 2;
 
 		total_scan = shrinker->nr;
 		shrinker->nr = 0;
@@ -407,7 +419,7 @@ static int shrink_list(struct list_head *page_list, struct scan_control *sc)
 		if (PageWriteback(page))
 			goto keep_locked;
 
-		referenced = page_referenced(page, 1, sc->priority <= 0);
+		referenced = page_referenced(page, 1);
 		/* In active use or really unfreeable?  Activate it. */
 		if (referenced && page_mapping_inuse(page))
 			goto activate_locked;
@@ -756,7 +768,7 @@ refill_inactive_zone(struct zone *zone, struct scan_control *sc)
 		if (page_mapped(page)) {
 			if (!reclaim_mapped ||
 			    (total_swap_pages == 0 && PageAnon(page)) ||
-			    page_referenced(page, 0, sc->priority <= 0)) {
+			    page_referenced(page, 0)) {
 				list_add(&page->lru, &l_active);
 				continue;
 			}
@@ -960,6 +972,8 @@ int try_to_free_pages(struct zone **zones, gfp_t gfp_mask)
 		sc.nr_reclaimed = 0;
 		sc.priority = priority;
 		sc.swap_cluster_max = SWAP_CLUSTER_MAX;
+		if (!priority)
+			disable_swap_token();
 		shrink_caches(zones, &sc);
 		shrink_slab(sc.nr_scanned, gfp_mask, lru_pages);
 		if (reclaim_state) {
@@ -1056,6 +1070,10 @@ loop_again:
 		int end_zone = 0;	/* Inclusive.  0 = ZONE_DMA */
 		unsigned long lru_pages = 0;
 
+		/* The swap token gets in the way of swapout... */
+		if (!priority)
+			disable_swap_token();
+
 		all_zones_ok = 1;
 
 		if (nr_pages == 0) {
@@ -1360,6 +1378,7 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
 	sc.nr_reclaimed = 0;
 	/* scan at the highest priority */
 	sc.priority = 0;
+	disable_swap_token();
 
 	if (nr_pages > SWAP_CLUSTER_MAX)
 		sc.swap_cluster_max = nr_pages;