Index: linux-2.6.15-rc2/include/linux/mmzone.h
===================================================================
--- linux-2.6.15-rc2.orig/include/linux/mmzone.h	2005-11-23 01:38:17.000000000 +0000
+++ linux-2.6.15-rc2/include/linux/mmzone.h	2005-11-23 01:40:09.000000000 +0000
@@ -157,6 +157,7 @@ struct zone {
 	unsigned long		nr_scan_inactive;
 	unsigned long		nr_active;
 	unsigned long		nr_inactive;
+	unsigned long		nr_unmapped;	   /* unmapped pages on LRU */
 	unsigned long		pages_scanned;	   /* since last reclaim */
 	int			all_unreclaimable; /* All pages pinned */
 
Index: linux-2.6.15-rc2/mm/vmscan.c
===================================================================
--- linux-2.6.15-rc2.orig/mm/vmscan.c	2005-11-20 03:25:03.000000000 +0000
+++ linux-2.6.15-rc2/mm/vmscan.c	2005-11-23 01:53:20.000000000 +0000
@@ -61,6 +61,8 @@ struct scan_control {
 	/* Incremented by the number of pages reclaimed */
 	unsigned long nr_reclaimed;
 
+	long nr_unmapped;		/* update zone->nr_unmapped */ 
+
 	unsigned long nr_mapped;	/* From page_state */
 
 	/* How many pages shrink_cache() should reclaim */
@@ -440,10 +442,10 @@ static int shrink_list(struct list_head 
 			case SWAP_AGAIN:
 				goto keep_locked;
 			case SWAP_SUCCESS:
-				; /* try to free the page below */
+				sc->nr_unmapped++;
+				/* try to free the page below */
 			}
 		}
-
 		if (PageDirty(page)) {
 			if (referenced)
 				goto keep_locked;
@@ -537,6 +539,7 @@ static int shrink_list(struct list_head 
 free_it:
 		unlock_page(page);
 		reclaimed++;
+		sc->nr_unmapped--;
 		if (!pagevec_add(&freed_pvec, page))
 			__pagevec_release_nonlru(&freed_pvec);
 		continue;
@@ -635,6 +638,7 @@ static void shrink_cache(struct zone *zo
 					     &page_list, &nr_scan);
 		zone->nr_inactive -= nr_taken;
 		zone->pages_scanned += nr_scan;
+		sc->nr_unmapped = 0;
 		spin_unlock_irq(&zone->lru_lock);
 
 		if (nr_taken == 0)
@@ -652,6 +656,7 @@ static void shrink_cache(struct zone *zo
 		sc->nr_to_reclaim -= nr_freed;
 
 		spin_lock_irq(&zone->lru_lock);
+		zone->nr_unmapped += sc->nr_unmapped;
 		/*
 		 * Put back any unfreeable pages.
 		 */