Index: linux/mm/page_alloc.c
===================================================================
--- linux.orig/mm/page_alloc.c	2004-10-04 15:11:58.000000000 -0700
+++ linux/mm/page_alloc.c	2004-10-12 07:48:39.000000000 -0700
@@ -43,6 +43,9 @@
 int numnodes = 1;
 EXPORT_SYMBOL(numnodes);
 int sysctl_lower_zone_protection = 0;
+#ifdef CONFIG_NUMA
+int sysctl_node_swap = 0;
+#endif
 
 EXPORT_SYMBOL(totalram_pages);
 EXPORT_SYMBOL(nr_swap_pages);
@@ -639,7 +642,16 @@
 			page = buffered_rmqueue(z, order, cold);
 			if (page) { 
 					zone_statistics(zonelist, z); 
-		       		goto got_pg;
+#ifdef CONFIG_NUMA
+				/*
+				 * If zone allocation leaves less than a (sysctl_node_swap * 10) %
+				 * of the zone free then invoke kswapd.
+				 * (to make it efficient we do (pages * sysctl_node_swap) / 1024))
+				 */
+				if (z->free_pages < (z->present_pages * sysctl_node_swap) << 10)
+					wakeup_kswapd(z);
+#endif
+       				goto got_pg;
 			}
 		}
 		min += z->pages_low * sysctl_lower_zone_protection;
Index: linux/kernel/sysctl.c
===================================================================
--- linux.orig/kernel/sysctl.c	2004-10-04 15:12:01.000000000 -0700
+++ linux/kernel/sysctl.c	2004-10-12 07:45:41.000000000 -0700
@@ -71,6 +71,9 @@
 extern int printk_ratelimit_burst;
 extern int shm_use_hugepages;
 extern int mmap_use_hugepages, mmap_hugepages_map_sz;
+#ifdef CONFIG_NUMA
+extern int sysctl_node_swap;
+#endif
 
 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 static int maxolduid = 65535;
@@ -890,6 +893,16 @@
  		.mode		= 0644,
  		.proc_handler	= &proc_dointvec,
  	},
+#ifdef CONFIG_NUMA
+	{
+		.ctl_name       = VM_NODE_SWAP,
+		.procname       = "node_swap",
+		.data           = &sysctl_node_swap,
+		.maxlen         = sizeof(sysctl_node_swap),
+		.mode           = 0644,
+		.proc_handler   = &proc_dointvec
+	},
+#endif
   	{ .ctl_name = 0 }
 };
 
Index: linux/include/linux/sysctl.h
===================================================================
--- linux.orig/include/linux/sysctl.h	2004-10-04 15:12:01.000000000 -0700
+++ linux/include/linux/sysctl.h	2004-10-12 07:36:40.000000000 -0700
@@ -175,6 +175,7 @@
  	VM_BLOCK_DUMP=24,       /* block dump mode */
  	VM_DISABLE_CAP_MLOCK=25,/* disable CAP_IPC_LOCK checking */
 	VM_HEAP_STACK_GAP=26,	/* int: page gap between heap and stack */
+	VM_NODE_SWAP=27,        /* Swap local node memory limit (in % *10) */
 };
 
 
Index: linux/mm/vmscan.c
===================================================================
--- linux.orig/mm/vmscan.c	2004-10-11 16:36:17.000000000 -0700
+++ linux/mm/vmscan.c	2004-10-12 07:35:30.000000000 -0700
@@ -1122,7 +1122,9 @@
  */
 void wakeup_kswapd(struct zone *zone)
 {
-	if (zone->free_pages > zone->pages_low)
+	extern int sysctl_node_swap;
+
+	if (zone->free_pages > (zone->present_pages * sysctl_node_swap) << 10 && zone->free_pages > zone->pages_low)
 		return;
 	if (!waitqueue_active(&zone->zone_pgdat->kswapd_wait))
 		return;