[PATCH] x86_64: Handle empty node zero

From: Daniel Yeisley <dan.yeisley@unisys.com>

It is possible to boot a Unisys ES7000 with CPUs from multiple cells, and not
also include the memory from those cells.  This can create a scenario where
node 0 has cpus, but no associated memory.  The system will boot fine in a
configuration where node 0 has memory, but nodes 2 and 3 do not.

[AK: I rechecked the code and generic code seems to indeed handle that already.
Dan's original patch had a change for mm/slab.c that seems to be already in now.]

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/x86_64/mm/srat.c b/arch/x86_64/mm/srat.c
index e1513532df2..474df22c6ed 100644
--- a/arch/x86_64/mm/srat.c
+++ b/arch/x86_64/mm/srat.c
@@ -399,8 +399,10 @@ int __init acpi_scan_nodes(unsigned long start, unsigned long end)
         /* First clean up the node list */
         for (i = 0; i < MAX_NUMNODES; i++) {
                 cutoff_node(i, start, end);
-                if ((nodes[i].end - nodes[i].start) < NODE_MIN_SIZE)
+                if ((nodes[i].end - nodes[i].start) < NODE_MIN_SIZE) {
                         unparse_node(i);
+                        node_set_offline(i);
+                }
         }
 
         if (acpi_numa <= 0)