rcu: Clean up flavor-related definitions and comments in update.c

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

kernel/rcu/update.c

@@ -332,7 +332,7 @@ void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array,
 	int i;
 	int j;
 
-	/* Initialize and register callbacks for each flavor specified. */
+	/* Initialize and register callbacks for each crcu_array element. */
 	for (i = 0; i < n; i++) {
 		if (checktiny &&
 		    (crcu_array[i] == call_rcu ||
@@ -697,19 +697,19 @@ static int __noreturn rcu_tasks_kthread(void *arg)
 
 		/*
 		 * Wait for all pre-existing t->on_rq and t->nvcsw
-		 * transitions to complete.  Invoking synchronize_sched()
+		 * transitions to complete.  Invoking synchronize_rcu()
 		 * suffices because all these transitions occur with
-		 * interrupts disabled.  Without this synchronize_sched(),
+		 * interrupts disabled.  Without this synchronize_rcu(),
 		 * a read-side critical section that started before the
 		 * grace period might be incorrectly seen as having started
 		 * after the grace period.
 		 *
-		 * This synchronize_sched() also dispenses with the
+		 * This synchronize_rcu() also dispenses with the
 		 * need for a memory barrier on the first store to
 		 * ->rcu_tasks_holdout, as it forces the store to happen
 		 * after the beginning of the grace period.
 		 */
-		synchronize_sched();
+		synchronize_rcu();
 
 		/*
 		 * There were callbacks, so we need to wait for an
@@ -736,7 +736,7 @@ static int __noreturn rcu_tasks_kthread(void *arg)
 		 * This does only part of the job, ensuring that all
 		 * tasks that were previously exiting reach the point
 		 * where they have disabled preemption, allowing the
-		 * later synchronize_sched() to finish the job.
+		 * later synchronize_rcu() to finish the job.
 		 */
 		synchronize_srcu(&tasks_rcu_exit_srcu);
 
@@ -786,20 +786,20 @@ static int __noreturn rcu_tasks_kthread(void *arg)
 		 * cause their RCU-tasks read-side critical sections to
 		 * extend past the end of the grace period.  However,
 		 * because these ->nvcsw updates are carried out with
-		 * interrupts disabled, we can use synchronize_sched()
+		 * interrupts disabled, we can use synchronize_rcu()
 		 * to force the needed ordering on all such CPUs.
 		 *
-		 * This synchronize_sched() also confines all
+		 * This synchronize_rcu() also confines all
 		 * ->rcu_tasks_holdout accesses to be within the grace
 		 * period, avoiding the need for memory barriers for
 		 * ->rcu_tasks_holdout accesses.
 		 *
-		 * In addition, this synchronize_sched() waits for exiting
+		 * In addition, this synchronize_rcu() waits for exiting
 		 * tasks to complete their final preempt_disable() region
 		 * of execution, cleaning up after the synchronize_srcu()
 		 * above.
 		 */
-		synchronize_sched();
+		synchronize_rcu();
 
 		/* Invoke the callbacks. */
 		while (list) {