Speed up numa_node_id by putting it directly into the PDA

Not go from the CPU number to an mapping array.
Mode number is often used now in fast paths.

Suggested by Eric Dumazet

Signed-off-by: Andi Kleen <ak@suse.de>

Index: linux/arch/x86_64/kernel/setup.c
===================================================================
--- linux.orig/arch/x86_64/kernel/setup.c
+++ linux/arch/x86_64/kernel/setup.c
@@ -818,7 +818,7 @@ static void __init amd_detect_cmp(struct
  		if (!node_online(node))
  			node = nearby_node(apicid);
  	}
-  	cpu_to_node[cpu] = node;
+	numa_set_node(cpu, node);
 
   	printk(KERN_INFO "CPU %d(%d) -> Node %d -> Core %d\n",
   			cpu, c->x86_num_cores, node, cpu_core_id[cpu]);
@@ -970,7 +970,7 @@ static void srat_detect_node(void)
 	node = apicid_to_node[hard_smp_processor_id()];
 	if (node == NUMA_NO_NODE)
 		node = 0;
-	cpu_to_node[cpu] = node;
+	numa_set_node(cpu, node);
 
 	if (acpi_numa > 0)
 		printk(KERN_INFO "CPU %d -> Node %d\n", cpu, node);
Index: linux/arch/x86_64/mm/numa.c
===================================================================
--- linux.orig/arch/x86_64/mm/numa.c
+++ linux/arch/x86_64/mm/numa.c
@@ -156,7 +156,7 @@ void __init numa_init_array(void)
 	for (i = 0; i < NR_CPUS; i++) {
 		if (cpu_to_node[i] != NUMA_NO_NODE)
 			continue;
-		cpu_to_node[i] = rr;
+ 		numa_set_node(i, rr);
 		rr = next_node(rr, node_online_map);
 		if (rr == MAX_NUMNODES)
 			rr = first_node(node_online_map);
@@ -242,7 +242,7 @@ void __init numa_initmem_init(unsigned l
 	nodes_clear(node_online_map);
 	node_set_online(0);
 	for (i = 0; i < NR_CPUS; i++)
-		cpu_to_node[i] = 0;
+		numa_set_node(i, 0);
 	node_to_cpumask[0] = cpumask_of_cpu(0);
 	setup_node_bootmem(0, start_pfn << PAGE_SHIFT, end_pfn << PAGE_SHIFT);
 }
@@ -252,6 +252,12 @@ __cpuinit void numa_add_cpu(int cpu)
 	set_bit(cpu, &node_to_cpumask[cpu_to_node(cpu)]);
 } 
 
+void __cpuinit numa_set_node(int cpu, int node)
+{
+	cpu_pda[cpu].nodenumber = node;
+	cpu_to_node[cpu] = node;
+}
+
 unsigned long __init numa_free_all_bootmem(void) 
 { 
 	int i;
Index: linux/arch/x86_64/mm/srat.c
===================================================================
--- linux.orig/arch/x86_64/mm/srat.c
+++ linux/arch/x86_64/mm/srat.c
@@ -203,7 +203,7 @@ int __init acpi_scan_nodes(unsigned long
 		if (cpu_to_node[i] == NUMA_NO_NODE)
 			continue;
 		if (!node_isset(cpu_to_node[i], nodes_parsed))
-			cpu_to_node[i] = NUMA_NO_NODE; 
+			numa_set_node(i, NUMA_NO_NODE);
 	}
 	numa_init_array();
 	return 0;
Index: linux/include/asm-x86_64/numa.h
===================================================================
--- linux.orig/include/asm-x86_64/numa.h
+++ linux/include/asm-x86_64/numa.h
@@ -17,6 +17,8 @@ extern void numa_add_cpu(int cpu);
 extern void numa_init_array(void);
 extern int numa_off;
 
+extern void numa_set_node(int cpu, int node);
+
 extern unsigned char apicid_to_node[256];
 
 #define NUMA_NO_NODE 0xff
Index: linux/include/asm-x86_64/pda.h
===================================================================
--- linux.orig/include/asm-x86_64/pda.h
+++ linux/include/asm-x86_64/pda.h
@@ -15,6 +15,7 @@ struct x8664_pda {
         int irqcount;		    /* Irq nesting counter. Starts with -1 */  	
 	int cpunumber;		    /* Logical CPU number */
 	char *irqstackptr;	/* top of irqstack */
+	int nodenumber;		    /* number of current node */
 	unsigned int __softirq_pending;
 	unsigned int __nmi_count;	/* number of NMI on this CPUs */
 	struct mm_struct *active_mm;
Index: linux/include/asm-x86_64/topology.h
===================================================================
--- linux.orig/include/asm-x86_64/topology.h
+++ linux/include/asm-x86_64/topology.h
@@ -28,6 +28,8 @@ extern int __node_distance(int, int);
 #define pcibus_to_node(bus)		((long)(bus->sysdata))	
 #define pcibus_to_cpumask(bus)		node_to_cpumask(pcibus_to_node(bus));
 
+#define numa_node_id()			read_pda(nodenumber)
+
 /* sched_domains SD_NODE_INIT for x86_64 machines */
 #define SD_NODE_INIT (struct sched_domain) {		\
 	.span			= CPU_MASK_NONE,	\
Index: linux/include/linux/mmzone.h
===================================================================
--- linux.orig/include/linux/mmzone.h
+++ linux/include/linux/mmzone.h
@@ -408,7 +408,9 @@ int lowmem_reserve_ratio_sysctl_handler(
 
 #include <linux/topology.h>
 /* Returns the number of the current Node. */
+#ifndef numa_node_id
 #define numa_node_id()		(cpu_to_node(raw_smp_processor_id()))
+#endif
 
 #ifndef CONFIG_NEED_MULTIPLE_NODES