2012-08-01 07:23:01

by Jesse Larrew

[permalink] [raw]
Subject: [PATCH] vphn: fix arch_update_cpu_topology() return value

>From 5dfd547532fca61462dc17fd0bb8e533002c4bc5 Mon Sep 17 00:00:00 2001
From: Jesse Larrew <[email protected]>
Date: Thu, 7 Jun 2012 16:04:34 -0500

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 <[email protected]>
---
arch/powerpc/mm/numa.c | 7 ++++---
1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 39b1597..59213cf 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)
--
1.7.7.6


Jesse Larrew
Software Engineer, Linux on Power Kernel Team
IBM Linux Technology Center
Phone: (512) 973-2052 (T/L: 363-2052)
[email protected]