--- linux-2.6.10/arch/x86_64/kernel/setup.c	2005-01-10 12:26:21.414190368 -0800
+++ linux-2.6.10.new.x86_64/arch/x86_64/kernel/setup.c	2005-01-10 12:30:53.656803200 -0800
@@ -738,7 +738,6 @@
 {
 #ifdef CONFIG_SMP
 	u32 	eax, ebx, ecx, edx;
-	int 	index_lsb, index_msb, tmp;
 	int 	cpu = smp_processor_id();
 	
 	if (!cpu_has(c, X86_FEATURE_HT))
@@ -750,8 +749,6 @@
 	if (smp_num_siblings == 1) {
 		printk(KERN_INFO  "CPU: Hyper-Threading is disabled\n");
 	} else if (smp_num_siblings > 1) {
-		index_lsb = 0;
-		index_msb = 31;
 		/*
 		 * At this point we only support two siblings per
 		 * processor package.
@@ -761,19 +758,8 @@
 			smp_num_siblings = 1;
 			return;
 		}
-		tmp = smp_num_siblings;
-		while ((tmp & 1) == 0) {
-			tmp >>=1 ;
-			index_lsb++;
-		}
-		tmp = smp_num_siblings;
-		while ((tmp & 0x80000000 ) == 0) {
-			tmp <<=1 ;
-			index_msb--;
-		}
-		if (index_lsb != index_msb )
-			index_msb++;
-		phys_proc_id[cpu] = phys_pkg_id(index_msb);
+
+		phys_proc_id[cpu] = c->x86_apicid >> hweight32(c->x86_num_cores - 1);
 		
 		printk(KERN_INFO  "CPU: Physical Processor ID: %d\n",
 		       phys_proc_id[cpu]);