rcu: Rename dyntick_save_progress_counter() into rcu_watching_snap_save()

The context_tracking.state RCU_DYNTICKS subvariable has been renamed to
RCU_WATCHING, and the 'dynticks' prefix can be dropped without losing any
meaning.

Suggested-by: Frederic Weisbecker <[email protected]>
Signed-off-by: Valentin Schneider <[email protected]>
Reviewed-by: Frederic Weisbecker <[email protected]>
Signed-off-by: Neeraj Upadhyay <[email protected]>

Author: valschneider

Documentation/RCU/Design/Memory-Ordering/TreeRCU-dyntick.svg

@@ -776,11 +776,11 @@ static void rcu_gpnum_ovf(struct rcu_node *rnp, struct rcu_data *rdp)
 }
 
 /*
- * Snapshot the specified CPU's dynticks counter so that we can later
+ * Snapshot the specified CPU's RCU_WATCHING counter so that we can later
  * credit them with an implicit quiescent state.  Return 1 if this CPU
  * is in dynticks idle mode, which is an extended quiescent state.
  */
-static int dyntick_save_progress_counter(struct rcu_data *rdp)
+static int rcu_watching_snap_save(struct rcu_data *rdp)
 {
 	/*
 	 * Full ordering between remote CPU's post idle accesses and updater's
@@ -805,7 +805,7 @@ static int dyntick_save_progress_counter(struct rcu_data *rdp)
 /*
  * Returns positive if the specified CPU has passed through a quiescent state
  * by virtue of being in or having passed through an dynticks idle state since
- * the last call to dyntick_save_progress_counter() for this same CPU, or by
+ * the last call to rcu_watching_snap_save() for this same CPU, or by
  * virtue of having been offline.
  *
  * Returns negative if the specified CPU needs a force resched.
@@ -1995,7 +1995,7 @@ static void rcu_gp_fqs(bool first_time)
 
 	if (first_time) {
 		/* Collect dyntick-idle snapshots. */
-		force_qs_rnp(dyntick_save_progress_counter);
+		force_qs_rnp(rcu_watching_snap_save);
 	} else {
 		/* Handle dyntick-idle and offline CPUs. */
 		force_qs_rnp(rcu_implicit_dynticks_qs);