x86: restore pda nodenumber field

  * Restore the nodenumber field in the x86_64 pda.  This field is slightly
    different than the x86_cpu_to_node_map mainly because it's a static
    indication of which node the cpu is on while the cpu to node map is a
    dyanamic mapping that may get reset if the cpu goes offline.  This also
    simplifies the numa_node_id() macro.

For inclusion into sched-devel/latest tree.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

3 files changed, 6 insertions, 1 deletions

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 03caa8e4351f..0dff17ee3d73 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -32,6 +32,7 @@ EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
 #define X86_64_NUMA     1
 
+/* map cpu index to node index */
 DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, NUMA_NO_NODE);
 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_node_map);
 #endif
@@ -155,6 +156,9 @@ void __cpuinit numa_set_node(int cpu, int node)
 {
         int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
 
+        if (node != NUMA_NO_NODE)
+                cpu_pda(cpu)->nodenumber = node;
+
         if (cpu_to_node_map)
                 cpu_to_node_map[cpu] = node;
 
diff --git a/include/asm-x86/pda.h b/include/asm-x86/pda.h
index 101fb9e11954..de2ad9ac35a9 100644
--- a/include/asm-x86/pda.h
+++ b/include/asm-x86/pda.h
@@ -22,6 +22,7 @@ struct x8664_pda {
                                            offset 40!!! */
 #endif
         char *irqstackptr;
+        int nodenumber;                 /* number of current node */
         unsigned int __softirq_pending;
         unsigned int __nmi_count;       /* number of NMI on this CPUs */
         short mmu_state;
diff --git a/include/asm-x86/topology.h b/include/asm-x86/topology.h
index dac09cb66dca..c0e6ff7671ea 100644
--- a/include/asm-x86/topology.h
+++ b/include/asm-x86/topology.h
@@ -66,7 +66,7 @@ extern cpumask_t node_to_cpumask_map[];
 DECLARE_EARLY_PER_CPU(int, x86_cpu_to_node_map);
 
 /* Returns the number of the current Node. */
-#define numa_node_id()  (per_cpu(x86_cpu_to_node_map, raw_smp_processor_id()))
+#define numa_node_id()          read_pda(nodenumber)
 
 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
 extern int cpu_to_node(int cpu);