IA64 zone reclaim

Set up a zone reclaim function for IA64. The zone reclaim function will
reclaim easily reclaimable pages. Off node allocations will occur if no
easily reclaimable pages exist anymore.

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

Index: linux-2.6.15-rc4/arch/ia64/mm/numa.c
===================================================================
--- linux-2.6.15-rc4.orig/arch/ia64/mm/numa.c	2005-11-30 22:25:15.000000000 -0800
+++ linux-2.6.15-rc4/arch/ia64/mm/numa.c	2005-12-05 10:12:14.000000000 -0800
@@ -17,6 +17,7 @@
 #include <linux/node.h>
 #include <linux/init.h>
 #include <linux/bootmem.h>
+#include <linux/swap.h>
 #include <asm/mmzone.h>
 #include <asm/numa.h>
 
@@ -71,3 +72,17 @@ int early_pfn_to_nid(unsigned long pfn)
 	return 0;
 }
 #endif
+
+/*
+ * Remove easily reclaimable local pages if watermarks would prevent a
+ * local allocation.
+ */
+int arch_zone_reclaim(struct zone *z, gfp_t  mask,
+				    unsigned int order)
+{
+	if (z->zone_pgdat->node_id == numa_node_id()) {
+		if (zone_reclaim(z, mask, 0, 0) > (1 << order))
+			return 1;
+	}
+	return 0;
+}
Index: linux-2.6.15-rc4/arch/ia64/Kconfig
===================================================================
--- linux-2.6.15-rc4.orig/arch/ia64/Kconfig	2005-11-30 22:25:15.000000000 -0800
+++ linux-2.6.15-rc4/arch/ia64/Kconfig	2005-12-03 13:30:27.000000000 -0800
@@ -338,6 +338,10 @@ config HAVE_ARCH_EARLY_PFN_TO_NID
 	def_bool y
 	depends on NEED_MULTIPLE_NODES
 
+config ARCH_ZONE_RECLAIM
+	def_bool y
+	depends on NUMA
+
 config IA32_SUPPORT
 	bool "Support for Linux/x86 binaries"
 	help