From 79c5fcebfe4021f326a6715009f0b6b622d5df92 Mon Sep 17 00:00:00 2001
From: Jesse Larrew <jlarrew@linux.vnet.ibm.com>
Date: Thu, 7 Jun 2012 16:04:34 -0500
Subject: 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>
---
 arch/powerpc/mm/numa.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

(limited to 'arch')

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)
-- 
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