Index: linux-2.6.8.1-ck/mm/page_alloc.c
===================================================================
--- linux-2.6.8.1-ck.orig/mm/page_alloc.c	2004-08-23 13:19:02.000000000 +1000
+++ linux-2.6.8.1-ck/mm/page_alloc.c	2004-08-25 23:30:54.000000000 +1000
@@ -725,8 +725,9 @@ __alloc_pages(unsigned int gfp_mask, uns
 		 */
 		if (rt_task(p))
 			min -= z->pages_low >> 1;
-		else
-			if (wait && z->free_pages < z->pages_unmapped)
+		else if (vm_mapped && wait && 
+			z->free_pages < z->pages_unmapped &&
+			z->free_pages > z->pages_low)
 				wakeup_kswapd(z);
 
 		if (z->free_pages >= min ||
Index: linux-2.6.8.1-ck/mm/vmscan.c
===================================================================
--- linux-2.6.8.1-ck.orig/mm/vmscan.c	2004-08-25 21:27:13.000000000 +1000
+++ linux-2.6.8.1-ck/mm/vmscan.c	2004-08-25 23:32:38.000000000 +1000
@@ -966,6 +966,20 @@ static int balance_pgdat(pg_data_t *pgda
 	sc.may_writepage = 0;
 	sc.nr_mapped = read_page_state(nr_mapped);
 
+	/*
+	 * Sanity check to ensure we don't have a stale maplimit set
+	 * and are calling balance_pgdat for a different reason.
+	 */
+	if (nr_pages)
+		maplimit = 0;
+	/*
+	 * kswapd does a light balance_pgdat() when there is less than 1/3
+	 * ram free provided there is less than vm_mapped % of that ram 
+	 * mapped.
+	 */
+	if (maplimit && sc.nr_mapped * 100 / total_memory > vm_mapped)
+		return 0;
+
 	inc_page_state(pageoutrun);
 
 	for (i = 0; i < pgdat->nr_zones; i++) {
@@ -978,15 +992,13 @@ static int balance_pgdat(pg_data_t *pgda
 		int all_zones_ok = 1;
 		int end_zone = 0;	/* Inclusive.  0 = ZONE_DMA */
 		unsigned long lru_pages = 0;
-		int mapped_ratio = sc.nr_mapped * 100 / total_memory;
 
-		if (maplimit && (mapped_ratio > vm_mapped ||
-			priority < DEF_PRIORITY))
-			/*
-			 * Evict pages only if mapped_ratio < vm_mapped and
-			 * only do low priority scanning.
-			 */
-				goto out;
+		/*
+		 * Only do low priority scanning if we're here due to
+		 * mapped watermark.
+		 */
+		if (maplimit && priority < DEF_PRIORITY)
+			goto out;
 		if (nr_pages == 0) {
 			/*
 			 * Scan in the highmem->dma direction for the highest
@@ -1142,12 +1154,13 @@ int kswapd(void *p)
 void wakeup_kswapd(struct zone *zone)
 {
 	if (zone->free_pages > zone->pages_unmapped)
-		return;
+		goto out;
 	if (zone->free_pages > zone->pages_low)
 		zone->zone_pgdat->maplimit = 1;
 	if (!waitqueue_active(&zone->zone_pgdat->kswapd_wait))
-		return;
+		goto out;
 	wake_up_interruptible(&zone->zone_pgdat->kswapd_wait);
+out:
 	zone->zone_pgdat->maplimit = 0;
 }