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 <frederic@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>

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

@@ -528,7 +528,7 @@
        font-style="normal"
        y="-8652.5312"
        x="2466.7822"
-       xml:space="preserve">dyntick_save_progress_counter()</text>
+       xml:space="preserve">rcu_watching_snap_save()</text>
     <text
        style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier"
        id="text202-7-2-7-2-0"

Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp-fqs.svg

@@ -844,7 +844,7 @@
      font-style="normal"
      y="1547.8876"
      x="4417.6396"
-     xml:space="preserve">dyntick_save_progress_counter()</text>
+     xml:space="preserve">rcu_watching_snap_save()</text>
   <g
      style="fill:none;stroke-width:0.025in"
      transform="translate(6501.9719,-10685.904)"

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

@@ -2974,7 +2974,7 @@
        font-style="normal"
        y="38114.047"
        x="-334.33856"
-       xml:space="preserve">dyntick_save_progress_counter()</text>
+       xml:space="preserve">rcu_watching_snap_save()</text>
     <g
        style="fill:none;stroke-width:0.025in"
        transform="translate(1749.9916,25880.249)"

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

@@ -516,7 +516,7 @@
        font-style="normal"
        y="-8652.5312"
        x="2466.7822"
-       xml:space="preserve">dyntick_save_progress_counter()</text>
+       xml:space="preserve">rcu_watching_snap_save()</text>
     <text
        style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier"
        id="text202-7-2-7-2-0"

kernel/rcu/tree.c

@@ -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);