cpusets: only wakeup kswapd for zones in the current cpuset

If we get under some memory pressure in a cpuset then kswapd is woken
up for all zones. This patch only wakes up kswapd in zones that are
part of the current cpuset.

Signed-off-by: Christoph Lameter <clameter@sgi.com>

Index: linux-2.6.16-rc2/mm/page_alloc.c
===================================================================
--- linux-2.6.16-rc2.orig/mm/page_alloc.c	2006-02-02 22:03:08.000000000 -0800
+++ linux-2.6.16-rc2/mm/page_alloc.c	2006-02-08 00:05:09.000000000 -0800
@@ -923,7 +923,8 @@ restart:
 		goto got_pg;
 
 	do {
-		wakeup_kswapd(*z, order);
+		if (cpuset_zone_allowed(*z, gfp_mask))
+			wakeup_kswapd(*z, order);
 	} while (*(++z));
 
 	/*