1 files changed, 46 insertions, 18 deletions

diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
index 976ebcf96f3e..df55a63f8866 100644
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -755,6 +755,24 @@ static void __cpuinit display_cacheinfo(struct cpuinfo_x86 *c)
         }
 }
 
+#ifdef CONFIG_NUMA
+static int nearby_node(int apicid)
+{
+        int i;
+        for (i = apicid - 1; i >= 0; i--) {
+                int node = apicid_to_node[i];
+                if (node != NUMA_NO_NODE && node_online(node))
+                        return node;
+        }
+        for (i = apicid + 1; i < MAX_LOCAL_APIC; i++) {
+                int node = apicid_to_node[i];
+                if (node != NUMA_NO_NODE && node_online(node))
+                        return node;
+        }
+        return first_node(node_online_map); /* Shouldn't happen */
+}
+#endif
+
 /*
  * On a AMD dual core setup the lower bits of the APIC id distingush the cores.
  * Assumes number of cores is a power of two.
@@ -763,9 +781,11 @@ static void __init amd_detect_cmp(struct cpuinfo_x86 *c)
 {
 #ifdef CONFIG_SMP
         int cpu = smp_processor_id();
-        int node = 0;
         unsigned bits;
+#ifdef CONFIG_NUMA
+        int node = 0;
         unsigned apicid = phys_proc_id[cpu];
+#endif
 
         bits = 0;
         while ((1 << bits) < c->x86_num_cores)
@@ -777,24 +797,32 @@ static void __init amd_detect_cmp(struct cpuinfo_x86 *c)
         phys_proc_id[cpu] >>= bits;
 
 #ifdef CONFIG_NUMA
-        /* When an ACPI SRAT table is available use the mappings from SRAT
-           instead. */
-        node = phys_proc_id[cpu];
-        if (acpi_numa > 0) {
-                if (apicid_to_node[apicid] != NUMA_NO_NODE)
-                        node = apicid_to_node[apicid];
-                else
-                        printk(KERN_ERR
-                               "SRAT: Didn't specify node for CPU %d(%d)\n",
-                               cpu, apicid);
-        }
-        if (!node_online(node))
-                node = first_node(node_online_map);
-        cpu_to_node[cpu] = node;
+        node = phys_proc_id[cpu];
+        if (apicid_to_node[apicid] != NUMA_NO_NODE)
+                node = apicid_to_node[apicid];
+        if (!node_online(node)) {
+                /* Two possibilities here:
+                   - The CPU is missing memory and no node was created.
+                   In that case try picking one from a nearby CPU
+                   - The APIC IDs differ from the HyperTransport node IDs
+                   which the K8 northbridge parsing fills in.
+                   Assume they are all increased by a constant offset,
+                   but in the same order as the HT nodeids.
+                   If that doesn't result in a usable node fall back to the
+                   path for the previous case.  */
+                int ht_nodeid = apicid - (phys_proc_id[0] << bits);
+                if (ht_nodeid >= 0 &&
+                    apicid_to_node[ht_nodeid] != NUMA_NO_NODE)
+                        node = apicid_to_node[ht_nodeid];
+                /* Pick a nearby node */
+                if (!node_online(node))
+                        node = nearby_node(apicid);
+        }
+        cpu_to_node[cpu] = node;
+
+        printk(KERN_INFO "CPU %d(%d) -> Node %d -> Core %d\n",
+                        cpu, c->x86_num_cores, node, cpu_core_id[cpu]);
 #endif
-
-        printk(KERN_INFO "CPU %d(%d) -> Node %d -> Core %d\n",
-                        cpu, c->x86_num_cores, node, cpu_core_id[cpu]);
 #endif
 }