[PATCH] i386: fix flat mode numa on a real numa system

If there is only 1 node in the system cpus should think they are apart of
some other node.

If cases where a real numa system boots the Flat numa option make sure the
cpus don't claim to be apart on a non-existent node.

Signed-off-by: Keith Mannthey <kmannth@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
index f948419c888a..efe07990e7fc 100644
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -642,9 +642,13 @@ static void map_cpu_to_logical_apicid(void)
 {
         int cpu = smp_processor_id();
         int apicid = logical_smp_processor_id();
+        int node = apicid_to_node(apicid);
+
+        if (!node_online(node))
+                node = first_online_node;
 
         cpu_2_logical_apicid[cpu] = apicid;
-        map_cpu_to_node(cpu, apicid_to_node(apicid));
+        map_cpu_to_node(cpu, node);
 }
 
 static void unmap_cpu_to_logical_apicid(int cpu)