Merge with master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6.git

1 files changed, 8 insertions, 7 deletions

diff --git a/arch/x86_64/kernel/smpboot.c b/arch/x86_64/kernel/smpboot.c
index b15761ff4101..fa25e39fe54d 100644
--- a/arch/x86_64/kernel/smpboot.c
+++ b/arch/x86_64/kernel/smpboot.c
@@ -492,6 +492,14 @@ void __cpuinit start_secondary(void)
          */
         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 @@ void __cpuinit start_secondary(void)
         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();
 }