Revert "x86, apic: Use logical flat on intel with <= 8 logical cpus"

[safe/jmp/linux-2.6] / arch / x86 / kernel / apic / apic.c

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index aa57c07..e80f291 100644 (file)
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -62,7 +62,7 @@ unsigned int boot_cpu_physical_apicid = -1U;
 /*
  * The highest APIC ID seen during enumeration.
  *
- * On AMD, this determines the messaging protocol we can use: if all APIC IDs
+ * This determines the messaging protocol we can use: if all APIC IDs
  * are in the 0 ... 7 range, then we can use logical addressing which
  * has some performance advantages (better broadcasting).
  *
@@ -1898,14 +1898,24 @@ void __cpuinit generic_processor_info(int apicid, int version)
                max_physical_apicid = apicid;
 
 #ifdef CONFIG_X86_32
-       switch (boot_cpu_data.x86_vendor) {
-       case X86_VENDOR_INTEL:
-               if (num_processors > 8)
-                       def_to_bigsmp = 1;
-               break;
-       case X86_VENDOR_AMD:
-               if (max_physical_apicid >= 8)
+       /*
+        * Would be preferable to switch to bigsmp when CONFIG_HOTPLUG_CPU=y
+        * but we need to work other dependencies like SMP_SUSPEND etc
+        * before this can be done without some confusion.
+        * if (CPU_HOTPLUG_ENABLED || num_processors > 8)
+        *       - Ashok Raj <ashok.raj@intel.com>
+        */
+       if (max_physical_apicid >= 8) {
+               switch (boot_cpu_data.x86_vendor) {
+               case X86_VENDOR_INTEL:
+                       if (!APIC_XAPIC(version)) {
+                               def_to_bigsmp = 0;
+                               break;
+                       }
+                       /* If P4 and above fall through */
+               case X86_VENDOR_AMD:
                        def_to_bigsmp = 1;
+               }
        }
 #endif