[tip:x86/urgent] x86: Set hotpluggable nodes in nodes_possible_map

[tip-bot for David Rientjes]

Commit-ID:  fefe0d8e9f0b2d1855ab4902c10399432cfc2e16
Gitweb:     http://git.kernel.org/tip/fefe0d8e9f0b2d1855ab4902c10399432cfc2e16
Author:     David Rientjes <rientjes@xxxxxxxxxx>
AuthorDate: Wed, 20 Jan 2010 12:10:47 -0800
Committer:  H. Peter Anvin <hpa@xxxxxxxxx>
CommitDate: Fri, 22 Jan 2010 02:44:43 -0800

x86: Set hotpluggable nodes in nodes_possible_map

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>
Cc: <stable@xxxxxxxxxx>
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxx>
---
 arch/x86/mm/srat_64.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/arch/x86/mm/srat_64.c b/arch/x86/mm/srat_64.c
index a271241..28c6876 100644
--- 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 start, unsigned long end)
 			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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