[PATCH] x86_64: fix cpu_to_node setup for sparse apic_ids

While booting with SMT disabled in bios, when using acpi srat to setup
cpu_to_node[], sparse apic_ids create problems.

Without this patch, intel x86_64 boxes with hyperthreading disabled in the
bios (and which rely on srat for numa setup) endup having incorrect values in
cpu_to_node[] arrays, causing sched domains to be built incorrectly etc.

Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 11 insertions, 6 deletions

diff --git a/arch/x86_64/mm/srat.c b/arch/x86_64/mm/srat.c
index ec1c4aca451..8e3d097a9dd 100644
--- a/arch/x86_64/mm/srat.c
+++ b/arch/x86_64/mm/srat.c
@@ -20,6 +20,9 @@
 
 static struct acpi_table_slit *acpi_slit;
 
+/* Internal processor count */
+static unsigned int __initdata num_processors = 0;
+
 static nodemask_t nodes_parsed __initdata;
 static nodemask_t nodes_found __initdata;
 static struct node nodes[MAX_NUMNODES] __initdata;
@@ -101,16 +104,18 @@ acpi_numa_processor_affinity_init(struct acpi_table_processor_affinity *pa)
                 bad_srat();
                 return;
         }
-        if (pa->apic_id >= NR_CPUS) {
-                printk(KERN_ERR "SRAT: lapic %u too large.\n",
-                       pa->apic_id);
+        if (num_processors >= NR_CPUS) {
+                printk(KERN_ERR "SRAT: Processor #%d (lapic %u) INVALID. (Max ID: %d).\n",
+                        num_processors, pa->apic_id, NR_CPUS);
                 bad_srat();
                 return;
         }
-        cpu_to_node[pa->apic_id] = node;
+        cpu_to_node[num_processors] = node;
         acpi_numa = 1;
-        printk(KERN_INFO "SRAT: PXM %u -> APIC %u -> Node %u\n",
-               pxm, pa->apic_id, node);
+        printk(KERN_INFO "SRAT: PXM %u -> APIC %u -> CPU %u -> Node %u\n",
+               pxm, pa->apic_id, num_processors, node);
+
+        num_processors++;
 }
 
 /* Callback for parsing of the Proximity Domain <-> Memory Area mappings */