Index: linux-2.6.15-rc1-mm2/mm/rmap.c
===================================================================
--- linux-2.6.15-rc1-mm2.orig/mm/rmap.c	2005-11-21 15:22:56.000000000 -0800
+++ linux-2.6.15-rc1-mm2/mm/rmap.c	2005-11-21 17:25:54.000000000 -0800
@@ -478,8 +478,10 @@ void page_add_file_rmap(struct page *pag
 	BUG_ON(PageAnon(page));
 	BUG_ON(!pfn_valid(page_to_pfn(page)));
 
-	if (atomic_inc_and_test(&page->_mapcount))
+	if (atomic_inc_and_test(&page->_mapcount)) {
 		inc_page_state(nr_mapped);
+		atomic_dec(&page_zone(page)->nr_cache);
+	}
 }
 
 /**
@@ -504,6 +506,7 @@ void page_remove_rmap(struct page *page)
 		if (page_test_and_clear_dirty(page))
 			set_page_dirty(page);
 		dec_page_state(nr_mapped);
+		atomic_inc(&page_zone(page)->nr_cache);
 	}
 }
 
Index: linux-2.6.15-rc1-mm2/include/linux/mmzone.h
===================================================================
--- linux-2.6.15-rc1-mm2.orig/include/linux/mmzone.h	2005-11-21 14:29:46.000000000 -0800
+++ linux-2.6.15-rc1-mm2/include/linux/mmzone.h	2005-11-21 17:19:27.000000000 -0800
@@ -168,6 +168,8 @@ struct zone {
 	/* A count of how many reclaimers are scanning this zone */
 	atomic_t		reclaim_in_progress;
 
+	/* Size of the pagecache */
+	atomic_t		nr_cache;
 	/*
 	 * prev_priority holds the scanning priority for this zone.  It is
 	 * defined as the scanning priority at which we achieved our reclaim