Fix misspellings of "system", "controller", "interrupt" and "necessary".

Fix the various misspellings of "system", controller", "interrupt" and
"[un]necessary".

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>

kernel/hrtimer.c

@@ -412,7 +412,7 @@ static int hrtimer_reprogram(struct hrtimer *timer,
 	/*
 	 * When the callback is running, we do not reprogram the clock event
 	 * device. The timer callback is either running on a different CPU or
-	 * the callback is executed in the hrtimer_interupt context. The
+	 * the callback is executed in the hrtimer_interrupt context. The
 	 * reprogramming is handled either by the softirq, which called the
 	 * callback or at the end of the hrtimer_interrupt.
 	 */

kernel/sched.c

@@ -5146,7 +5146,7 @@ static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu)
 }
 
 /*
- * Figure out where task on dead CPU should go, use force if neccessary.
+ * Figure out where task on dead CPU should go, use force if necessary.
  * NOTE: interrupts should be disabled by the caller
  */
 static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
@@ -5525,7 +5525,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
 
 	case CPU_ONLINE:
 	case CPU_ONLINE_FROZEN:
-		/* Strictly unneccessary, as first user will wake it. */
+		/* Strictly unnecessary, as first user will wake it. */
 		wake_up_process(cpu_rq(cpu)->migration_thread);
 		break;
 

kernel/taskstats.c

@@ -263,7 +263,7 @@ out:
 
 	stats->version = TASKSTATS_VERSION;
 	/*
-	 * Accounting subsytems can also add calls here to modify
+	 * Accounting subsystems can also add calls here to modify
 	 * fields of taskstats.
 	 */
 	return rc;