[IA64] Fix build breakage

In commit 0ac0c0d0f837c499afd02a802f9cf52d3027fa3b
cpusets: randomize node rotor used in cpuset_mem_spread_node()

Jack Steiner fixed a problem with too many small tasks being
assigned to node 0. Copy his code to ia64 to avoid build error.

    arch/ia64/kernel/smpboot.c:641: error: ‘cpu_to_node_map’ undeclared (first use in this function)

In commit 3bccd996276b108c138e8176793a26ecef54d573
numa: ia64: use generic percpu var numa_node_id() implementation

Lee Schermerhorn added some set_numa_node() calls - but these
only work on CONFIG_NUMA=y configurations. Surround the calls
with #ifdef CONFIG_NUMA

Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/arch/ia64/mm/numa.c b/arch/ia64/mm/numa.c
index 3efea7d0a351..2437718bd6b1 100644
--- a/arch/ia64/mm/numa.c
+++ b/arch/ia64/mm/numa.c
@@ -17,6 +17,7 @@
 #include <linux/init.h>
 #include <linux/bootmem.h>
 #include <linux/module.h>
+#include <linux/random.h>
 #include <asm/mmzone.h>
 #include <asm/numa.h>
 
@@ -50,6 +51,22 @@ paddr_to_nid(unsigned long paddr)
 	return (i < num_node_memblks) ? node_memblk[i].nid : (num_node_memblks ? -1 : 0);
 }
 
+/*
+ * Return the bit number of a random bit set in the nodemask.
+ *   (returns -1 if nodemask is empty)
+ */
+int __node_random(const nodemask_t *maskp)
+{
+	int w, bit = -1;
+
+	w = nodes_weight(*maskp);
+	if (w)
+		bit = bitmap_ord_to_pos(maskp->bits,
+			get_random_int() % w, MAX_NUMNODES);
+	return bit;
+}
+EXPORT_SYMBOL(__node_random);
+
 #if defined(CONFIG_SPARSEMEM) && defined(CONFIG_NUMA)
 /*
  * Because of holes evaluate on section limits.