powerpc/vphn: Fix arch_update_cpu_topology() return value

arch_update_cpu_topology() should only return 1 when the topology has
actually changed, and should return 0 otherwise.

This patch fixes a potential bug where rebuild_sched_domains() would
reinitialize the sched domains even when the topology hasn't changed.

Signed-off-by: Jesse Larrew <jlarrew@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 39b159751c35..59213cfaeca9 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -1436,11 +1436,11 @@ static long vphn_get_associativity(unsigned long cpu,
 
 /*
  * Update the node maps and sysfs entries for each cpu whose home node
- * has changed.
+ * has changed. Returns 1 when the topology has changed, and 0 otherwise.
  */
 int arch_update_cpu_topology(void)
 {
-        int cpu, nid, old_nid;
+        int cpu, nid, old_nid, changed = 0;
         unsigned int associativity[VPHN_ASSOC_BUFSIZE] = {0};
         struct device *dev;
 
@@ -1466,9 +1466,10 @@ int arch_update_cpu_topology(void)
                 dev = get_cpu_device(cpu);
                 if (dev)
                         kobject_uevent(&dev->kobj, KOBJ_CHANGE);
+                changed = 1;
         }
 
-        return 1;
+        return changed;
 }
 
 static void topology_work_fn(struct work_struct *work)