2 files changed, 9 insertions, 8 deletions

diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c
index f5bc7e1be801..a5e34d655965 100644
--- a/arch/i386/kernel/nmi.c
+++ b/arch/i386/kernel/nmi.c
@@ -195,6 +195,8 @@ static __cpuinit inline int nmi_known_cpu(void)
         return 0;
 }
 
+static int endflag __initdata = 0;
+
 #ifdef CONFIG_SMP
 /* The performance counters used by NMI_LOCAL_APIC don't trigger when
  * the CPU is idle. To make sure the NMI watchdog really ticks on all
@@ -202,7 +204,6 @@ static __cpuinit inline int nmi_known_cpu(void)
  */
 static __init void nmi_cpu_busy(void *data)
 {
-        volatile int *endflag = data;
         local_irq_enable_in_hardirq();
         /* Intentionally don't use cpu_relax here. This is
            to make sure that the performance counter really ticks,
@@ -210,14 +211,13 @@ static __init void nmi_cpu_busy(void *data)
            pause instruction. On a real HT machine this is fine because
            all other CPUs are busy with "useless" delay loops and don't
            care if they get somewhat less cycles. */
-        while (*endflag == 0)
-                barrier();
+        while (endflag == 0)
+                mb();
 }
 #endif
 
 static int __init check_nmi_watchdog(void)
 {
-        volatile int endflag = 0;
         unsigned int *prev_nmi_count;
         int cpu;
 
diff --git a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c
index 27e95e7922c1..186aebbae32d 100644
--- a/arch/x86_64/kernel/nmi.c
+++ b/arch/x86_64/kernel/nmi.c
@@ -193,6 +193,8 @@ void nmi_watchdog_default(void)
                 nmi_watchdog = NMI_IO_APIC;
 }
 
+static int endflag __initdata = 0;
+
 #ifdef CONFIG_SMP
 /* The performance counters used by NMI_LOCAL_APIC don't trigger when
  * the CPU is idle. To make sure the NMI watchdog really ticks on all
@@ -200,7 +202,6 @@ void nmi_watchdog_default(void)
  */
 static __init void nmi_cpu_busy(void *data)
 {
-        volatile int *endflag = data;
         local_irq_enable_in_hardirq();
         /* Intentionally don't use cpu_relax here. This is
            to make sure that the performance counter really ticks,
@@ -208,14 +209,13 @@ static __init void nmi_cpu_busy(void *data)
            pause instruction. On a real HT machine this is fine because
            all other CPUs are busy with "useless" delay loops and don't
            care if they get somewhat less cycles. */
-        while (*endflag == 0)
-                barrier();
+        while (endflag == 0)
+                mb();
 }
 #endif
 
 int __init check_nmi_watchdog (void)
 {
-        volatile int endflag = 0;
         int *counts;
         int cpu;
 
@@ -256,6 +256,7 @@ int __init check_nmi_watchdog (void)
         if (!atomic_read(&nmi_active)) {
                 kfree(counts);
                 atomic_set(&nmi_active, -1);
+                endflag = 1;
                 return -1;
         }
         endflag = 1;