cpumask: Optimize cpumask_of_cpu in kernel/time/tick-common.c

  * Optimize various places where a pointer to the cpumask_of_cpu value
    will result in reducing stack pressure.
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/time/tick-common.c

@@ -135,7 +135,7 @@ void tick_setup_periodic(struct clock_event_device *dev, int broadcast)
  */
 static void tick_setup_device(struct tick_device *td,
 			      struct clock_event_device *newdev, int cpu,
-			      cpumask_t cpumask)
+			      const cpumask_t *cpumask)
 {
 	ktime_t next_event;
 	void (*handler)(struct clock_event_device *) = NULL;
@@ -169,8 +169,8 @@ static void tick_setup_device(struct tick_device *td,
 	 * When the device is not per cpu, pin the interrupt to the
 	 * current cpu:
 	 */
-	if (!cpus_equal(newdev->cpumask, cpumask))
-		irq_set_affinity(newdev->irq, cpumask);
+	if (!cpus_equal(newdev->cpumask, *cpumask))
+		irq_set_affinity(newdev->irq, *cpumask);
 
 	/*
 	 * When global broadcasting is active, check if the current
@@ -196,20 +196,20 @@ static int tick_check_new_device(struct clock_event_device *newdev)
 	struct tick_device *td;
 	int cpu, ret = NOTIFY_OK;
 	unsigned long flags;
-	cpumask_t cpumask;
+	cpumask_of_cpu_ptr_declare(cpumask);
 
 	spin_lock_irqsave(&tick_device_lock, flags);
 
 	cpu = smp_processor_id();
+	cpumask_of_cpu_ptr_next(cpumask, cpu);
 	if (!cpu_isset(cpu, newdev->cpumask))
 		goto out_bc;
 
 	td = &per_cpu(tick_cpu_device, cpu);
 	curdev = td->evtdev;
-	cpumask = cpumask_of_cpu(cpu);
 
 	/* cpu local device ? */
-	if (!cpus_equal(newdev->cpumask, cpumask)) {
+	if (!cpus_equal(newdev->cpumask, *cpumask)) {
 
 		/*
 		 * If the cpu affinity of the device interrupt can not
@@ -222,7 +222,7 @@ static int tick_check_new_device(struct clock_event_device *newdev)
 		 * If we have a cpu local device already, do not replace it
 		 * by a non cpu local device
 		 */
-		if (curdev && cpus_equal(curdev->cpumask, cpumask))
+		if (curdev && cpus_equal(curdev->cpumask, *cpumask))
 			goto out_bc;
 	}