diff --git a/arch/x86_64/kernel/smpboot.c b/arch/x86_64/kernel/smpboot.c
index b15761f..fa25e39 100644
--- a/arch/x86_64/kernel/smpboot.c
+++ b/arch/x86_64/kernel/smpboot.c
@@ -492,6 +492,14 @@
 	 */
 	set_cpu_sibling_map(smp_processor_id());
 
+	/* 
+  	 * Wait for TSC sync to not schedule things before.
+	 * We still process interrupts, which could see an inconsistent
+	 * time in that window unfortunately. 
+	 * Do this here because TSC sync has global unprotected state.
+ 	 */
+	tsc_sync_wait();
+
 	/*
 	 * We need to hold call_lock, so there is no inconsistency
 	 * between the time smp_call_function() determines number of
@@ -509,13 +517,6 @@
 	per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
 	unlock_ipi_call_lock();
 
-	mb();
-
-	/* Wait for TSC sync to not schedule things before.
-	   We still process interrupts, which could see an inconsistent
-	   time in that window unfortunately. */
-	tsc_sync_wait();
-
 	cpu_idle();
 }