diff -urN linux-2.6.17-rc2-git6.orig/arch/i386/kernel/smpboot.c linux-2.6.17-rc2-git6/arch/i386/kernel/smpboot.c
--- linux-2.6.17-rc2-git6.orig/arch/i386/kernel/smpboot.c	2006-04-25 15:14:30.000000000 -0600
+++ linux-2.6.17-rc2-git6/arch/i386/kernel/smpboot.c	2006-04-25 12:02:45.000000000 -0600
@@ -108,6 +108,8 @@
 			{ [0 ... NR_CPUS-1] = 0xff };
 EXPORT_SYMBOL(x86_cpu_to_apicid);
 
+u8 apicid_2_node[MAX_APICID] = { [0 ... MAX_APICID-1] = 0 };
+
 /*
  * Trampoline 80x86 program as an array.
  */
@@ -640,7 +642,7 @@
 	int apicid = logical_smp_processor_id();
 
 	cpu_2_logical_apicid[cpu] = apicid;
-	map_cpu_to_node(cpu, apicid_to_node(apicid));
+	map_cpu_to_node(cpu, apicid_to_node(hard_smp_processor_id()));
 }
 
 static void unmap_cpu_to_logical_apicid(int cpu)
@@ -943,6 +945,7 @@
 
 	irq_ctx_init(cpu);
 
+	x86_cpu_to_apicid[cpu] = apicid;
 	/*
 	 * This grunge runs the startup process for
 	 * the targeted processor.
diff -urN linux-2.6.17-rc2-git6.orig/arch/i386/kernel/srat.c linux-2.6.17-rc2-git6/arch/i386/kernel/srat.c
--- linux-2.6.17-rc2-git6.orig/arch/i386/kernel/srat.c	2006-03-19 22:53:29.000000000 -0700
+++ linux-2.6.17-rc2-git6/arch/i386/kernel/srat.c	2006-04-25 11:56:45.000000000 -0600
@@ -58,6 +58,8 @@
 static int num_memory_chunks;		/* total number of memory chunks */
 static int zholes_size_init;
 static unsigned long zholes_size[MAX_NUMNODES * MAX_NR_ZONES];
+static u8 apicid_to_pxm[MAX_APICID] = { [0 ... MAX_APICID-1] = 0 };
+extern u8 apicid_2_node[];
 
 extern void * boot_ioremap(unsigned long, unsigned long);
 
@@ -73,6 +75,8 @@
 	/* mark this node as "seen" in node bitmap */
 	BMAP_SET(pxm_bitmap, cpu_affinity->proximity_domain);
 
+	apicid_to_pxm[cpu_affinity->apic_id] = cpu_affinity->proximity_domain;
+
 	printk("CPU 0x%02X in proximity domain 0x%02X\n",
 		cpu_affinity->apic_id, cpu_affinity->proximity_domain);
 }
@@ -298,6 +302,10 @@
 	printk("Number of logical nodes in system = %d\n", num_online_nodes());
 	printk("Number of memory chunks in system = %d\n", num_memory_chunks);
 
+	for (i = 0; i < MAX_APICID; i++) {
+		apicid_2_node[i] = pxm_to_nid_map[apicid_to_pxm[i]];
+	}
+	
 	for (j = 0; j < num_memory_chunks; j++){
 		struct node_memory_chunk_s * chunk = &node_memory_chunk[j];
 		printk("chunk %d nid %d start_pfn %08lx end_pfn %08lx\n",
diff -urN linux-2.6.17-rc2-git6.orig/include/asm-i386/mach-summit/mach_apic.h linux-2.6.17-rc2-git6/include/asm-i386/mach-summit/mach_apic.h
--- linux-2.6.17-rc2-git6.orig/include/asm-i386/mach-summit/mach_apic.h	2006-03-19 22:53:29.000000000 -0700
+++ linux-2.6.17-rc2-git6/include/asm-i386/mach-summit/mach_apic.h	2006-04-25 11:56:45.000000000 -0600
@@ -43,6 +43,7 @@
 
 extern u8 bios_cpu_apicid[];
 extern u8 cpu_2_logical_apicid[];
+extern u8 apicid_2_node[];
 
 static inline void init_apic_ldr(void)
 {
@@ -86,7 +87,7 @@
 
 static inline int apicid_to_node(int logical_apicid)
 {
-	return logical_apicid >> 5;          /* 2 clusterids per CEC */
+	return apicid_2_node[logical_apicid];
 }
 
 /* Mapping from cpu number to logical apicid */