5 files changed, 34 insertions, 7 deletions

diff --git a/arch/i386/kernel/apm.c b/arch/i386/kernel/apm.c
index b75cff25de4b..199016927541 100644
--- a/arch/i386/kernel/apm.c
+++ b/arch/i386/kernel/apm.c
@@ -785,7 +785,11 @@ static int apm_do_idle(void)
         polling = !!(current_thread_info()->status & TS_POLLING);
         if (polling) {
                 current_thread_info()->status &= ~TS_POLLING;
-                smp_mb__after_clear_bit();
+                /*
+                 * TS_POLLING-cleared state must be visible before we
+                 * test NEED_RESCHED:
+                 */
+                smp_mb();
         }
         if (!need_resched()) {
                 idled = 1;
diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
index 99308510a17c..c641056233a6 100644
--- a/arch/i386/kernel/process.c
+++ b/arch/i386/kernel/process.c
@@ -102,7 +102,12 @@ void default_idle(void)
 {
         if (!hlt_counter && boot_cpu_data.hlt_works_ok) {
                 current_thread_info()->status &= ~TS_POLLING;
-                smp_mb__after_clear_bit();
+                /*
+                 * TS_POLLING-cleared state must be visible before we
+                 * test NEED_RESCHED:
+                 */
+                smp_mb();
+
                 local_irq_disable();
                 if (!need_resched())
                         safe_halt();    /* enables interrupts racelessly */
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index 51922b98086a..17685abaf496 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -268,10 +268,16 @@ cpu_idle (void)
 
         /* endless idle loop with no priority at all */
         while (1) {
-                if (can_do_pal_halt)
+                if (can_do_pal_halt) {
                         current_thread_info()->status &= ~TS_POLLING;
-                else
+                        /*
+                         * TS_POLLING-cleared state must be visible before we
+                         * test NEED_RESCHED:
+                         */
+                        smp_mb();
+                } else {
                         current_thread_info()->status |= TS_POLLING;
+                }
 
                 if (!need_resched()) {
                         void (*idle)(void);
diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c
index a418ee4c8c62..cbbc6adc1a92 100644
--- a/arch/x86_64/kernel/process.c
+++ b/arch/x86_64/kernel/process.c
@@ -109,7 +109,11 @@ void exit_idle(void)
 static void default_idle(void)
 {
         current_thread_info()->status &= ~TS_POLLING;
-        smp_mb__after_clear_bit();
+        /*
+         * TS_POLLING-cleared state must be visible before we
+         * test NEED_RESCHED:
+         */
+        smp_mb();
         local_irq_disable();
         if (!need_resched()) {
                 /* Enables interrupts one instruction before HLT.
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 65b3f056ad89..6dac6050bb5a 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -211,7 +211,11 @@ acpi_processor_power_activate(struct acpi_processor *pr,
 static void acpi_safe_halt(void)
 {
         current_thread_info()->status &= ~TS_POLLING;
-        smp_mb__after_clear_bit();
+        /*
+         * TS_POLLING-cleared state must be visible before we
+         * test NEED_RESCHED:
+         */
+        smp_mb();
         if (!need_resched())
                 safe_halt();
         current_thread_info()->status |= TS_POLLING;
@@ -345,7 +349,11 @@ static void acpi_processor_idle(void)
          */
         if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
                 current_thread_info()->status &= ~TS_POLLING;
-                smp_mb__after_clear_bit();
+                /*
+                 * TS_POLLING-cleared state must be visible before we
+                 * test NEED_RESCHED:
+                 */
+                smp_mb();
                 if (need_resched()) {
                         current_thread_info()->status |= TS_POLLING;
                         local_irq_enable();