[07/74] x86: Set hotpluggable nodes in nodes_possible_map

From: Greg KH
Date: Thu Feb 04 2010 - 12:37:57 EST


2.6.32-stable review patch. If anyone has any objections, please let us know.

------------------

From: David Rientjes <rientjes@xxxxxxxxxx>

commit 3a5fc0e40cb467e692737bc798bc99773c81e1e2 upstream.

nodes_possible_map does not currently include nodes that have SRAT
entries that are all ACPI_SRAT_MEM_HOT_PLUGGABLE since the bit is
cleared in nodes_parsed if it does not have an online address range.

Unequivocally setting the bit in nodes_parsed is insufficient since
existing code, such as acpi_get_nodes(), assumes all nodes in the map
have online address ranges. In fact, all code using nodes_parsed
assumes such nodes represent an address range of online memory.

nodes_possible_map is created by unioning nodes_parsed and
cpu_nodes_parsed; the former represents nodes with online memory and
the latter represents memoryless nodes. We now set the bit for
hotpluggable nodes in cpu_nodes_parsed so that it also gets set in
nodes_possible_map.

[ hpa: Haicheng Li points out that this makes the naming of the
variable cpu_nodes_parsed somewhat counterintuitive. However, leave
it as is in the interest of keeping the pure bug fix patch small. ]

Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
Tested-by: Haicheng Li <haicheng.li@xxxxxxxxxxxxxxx>
LKML-Reference: <alpine.DEB.2.00.1001201152040.30528@xxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
arch/x86/mm/srat_64.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/arch/x86/mm/srat_64.c
+++ b/arch/x86/mm/srat_64.c
@@ -229,9 +229,11 @@ update_nodes_add(int node, unsigned long
printk(KERN_ERR "SRAT: Hotplug zone not continuous. Partly ignored\n");
}

- if (changed)
+ if (changed) {
+ node_set(node, cpu_nodes_parsed);
printk(KERN_INFO "SRAT: hot plug zone found %Lx - %Lx\n",
nd->start, nd->end);
+ }
}

/* Callback for parsing of the Proximity Domain <-> Memory Area mappings */


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