Re: [tip:x86/urgent] x86/uv: fix init of memory-less nodes

[Jack Steiner <steiner@sgi.com>]

x86/uv: fix init of memory-less nodes

Add support for nodes that have cpus but no memory.
The current code was failing to add these nodes
to the nodes_present_map.

[ Impact: fix potential boot crash on memory-less nodes. ]

Signed-off-by: Jack Steiner <steiner@sgi.com>



---

Fixes case caught by David - missed support for the x2apic SRAT table.



 arch/x86/mm/srat_64.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Index: linux/arch/x86/mm/srat_64.c
===================================================================
--- linux.orig/arch/x86/mm/srat_64.c	2009-04-17 15:12:13.000000000 -0500
+++ linux/arch/x86/mm/srat_64.c	2009-04-17 15:15:15.000000000 -0500
@@ -28,6 +28,7 @@ int acpi_numa __initdata;
 static struct acpi_table_slit *acpi_slit;
 
 static nodemask_t nodes_parsed __initdata;
+static nodemask_t cpu_nodes_parsed __initdata;
 static struct bootnode nodes[MAX_NUMNODES] __initdata;
 static struct bootnode nodes_add[MAX_NUMNODES];
 static int found_add_area __initdata;
@@ -141,6 +142,7 @@ acpi_numa_x2apic_affinity_init(struct ac
 
 	apic_id = pa->apic_id;
 	apicid_to_node[apic_id] = node;
+	node_set(node, cpu_nodes_parsed);
 	acpi_numa = 1;
 	printk(KERN_INFO "SRAT: PXM %u -> APIC %u -> Node %u\n",
 	       pxm, apic_id, node);
@@ -174,6 +176,7 @@ acpi_numa_processor_affinity_init(struct
 	else
 		apic_id = pa->apic_id;
 	apicid_to_node[apic_id] = node;
+	node_set(node, cpu_nodes_parsed);
 	acpi_numa = 1;
 	printk(KERN_INFO "SRAT: PXM %u -> APIC %u -> Node %u\n",
 	       pxm, apic_id, node);
@@ -402,7 +405,8 @@ int __init acpi_scan_nodes(unsigned long
 		return -1;
 	}
 
-	node_possible_map = nodes_parsed;
+	/* Account for nodes with cpus and no memory */
+	nodes_or(node_possible_map, nodes_parsed, cpu_nodes_parsed);
 
 	/* Finally register nodes */
 	for_each_node_mask(i, node_possible_map)