intel_idle: simplify test for leave_mm()
Len Brown [Sat, 16 Oct 2010 00:43:06 +0000 (20:43 -0400)]
A run-time test to invoke leave_mm() for the deepest
supported C-state is redundant, since the appropriate
C-states already have flags with CPUIDLE_FLAG_TLB_FLUSHED set.

Signed-off-by: Len Brown <len.brown@intel.com>

drivers/idle/intel_idle.c

index c37ef64..ad0fb01 100644 (file)
@@ -186,13 +186,10 @@ static int intel_idle(struct cpuidle_device *dev, struct cpuidle_state *state)
        local_irq_disable();
 
        /*
-        * If the state flag indicates that the TLB will be flushed or if this
-        * is the deepest c-state supported, do a voluntary leave mm to avoid
-        * costly and mostly unnecessary wakeups for flushing the user TLB's
-        * associated with the active mm.
+        * leave_mm() to avoid costly and often unnecessary wakeups
+        * for flushing the user TLB's associated with the active mm.
         */
-       if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED ||
-           (&dev->states[dev->state_count - 1] == state))
+       if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED)
                leave_mm(cpu);
 
        if (!(lapic_timer_reliable_states & (1 << (cstate))))