1 files changed, 15 insertions, 7 deletions

diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c
index 5e95b257ee26..49f7fac6229e 100644
--- a/arch/x86_64/kernel/process.c
+++ b/arch/x86_64/kernel/process.c
@@ -238,20 +238,28 @@ void cpu_idle (void)
  * We execute MONITOR against need_resched and enter optimized wait state
  * through MWAIT. Whenever someone changes need_resched, we would be woken
  * up from MWAIT (without an IPI).
+ *
+ * New with Core Duo processors, MWAIT can take some hints based on CPU
+ * capability.
  */
-static void mwait_idle(void)
+void mwait_idle_with_hints(unsigned long eax, unsigned long ecx)
 {
-        local_irq_enable();
-
-        while (!need_resched()) {
+        if (!need_resched()) {
                 __monitor((void *)&current_thread_info()->flags, 0, 0);
                 smp_mb();
-                if (need_resched())
-                        break;
-                __mwait(0, 0);
+                if (!need_resched())
+                        __mwait(eax, ecx);
         }
 }
 
+/* Default MONITOR/MWAIT with no hints, used for default C1 state */
+static void mwait_idle(void)
+{
+        local_irq_enable();
+        while (!need_resched())
+                mwait_idle_with_hints(0,0);
+}
+
 void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
 {
         static int printed;