rcu: Rename rcu_dynticks_in_eqs() into rcu_watching_snap_in_eqs()

The context_tracking.state RCU_DYNTICKS subvariable has been renamed to
RCU_WATCHING, reflect that change in the related helpers.

While at it, update a comment that still refers to rcu_dynticks_snap(),
which was removed by commit:

  7be2e6323b9b ("rcu: Remove full memory barrier on RCU stall printout")
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>

kernel/rcu/tree.c

@@ -300,10 +300,10 @@ static void rcu_watching_online(void)
 }
 
 /*
- * Return true if the snapshot returned from rcu_dynticks_snap()
+ * Return true if the snapshot returned from ct_rcu_watching()
  * indicates that RCU is in an extended quiescent state.
  */
-static bool rcu_dynticks_in_eqs(int snap)
+static bool rcu_watching_snap_in_eqs(int snap)
 {
 	return !(snap & CT_RCU_WATCHING);
 }
@@ -783,7 +783,7 @@ static int dyntick_save_progress_counter(struct rcu_data *rdp)
 	 * updater's accesses is enforced by the below acquire semantic.
 	 */
 	rdp->dynticks_snap = ct_rcu_watching_cpu_acquire(rdp->cpu);
-	if (rcu_dynticks_in_eqs(rdp->dynticks_snap)) {
+	if (rcu_watching_snap_in_eqs(rdp->dynticks_snap)) {
 		trace_rcu_fqs(rcu_state.name, rdp->gp_seq, rdp->cpu, TPS("dti"));
 		rcu_gpnum_ovf(rdp->mynode, rdp);
 		return 1;
@@ -4805,7 +4805,7 @@ rcu_boot_init_percpu_data(int cpu)
 	rdp->grpmask = leaf_node_cpu_bit(rdp->mynode, cpu);
 	INIT_WORK(&rdp->strict_work, strict_work_handler);
 	WARN_ON_ONCE(ct->nesting != 1);
-	WARN_ON_ONCE(rcu_dynticks_in_eqs(ct_rcu_watching_cpu(cpu)));
+	WARN_ON_ONCE(rcu_watching_snap_in_eqs(ct_rcu_watching_cpu(cpu)));
 	rdp->barrier_seq_snap = rcu_state.barrier_sequence;
 	rdp->rcu_ofl_gp_seq = rcu_state.gp_seq;
 	rdp->rcu_ofl_gp_state = RCU_GP_CLEANED;

kernel/rcu/tree_exp.h

@@ -377,7 +377,7 @@ static void __sync_rcu_exp_select_node_cpus(struct rcu_exp_work *rewp)
 			 * below acquire semantic.
 			 */
 			snap = ct_rcu_watching_cpu_acquire(cpu);
-			if (rcu_dynticks_in_eqs(snap))
+			if (rcu_watching_snap_in_eqs(snap))
 				mask_ofl_test |= mask;
 			else
 				rdp->exp_dynticks_snap = snap;

kernel/rcu/tree_stall.h

@@ -501,7 +501,7 @@ static void print_cpu_stall_info(int cpu)
 	}
 	delta = rcu_seq_ctr(rdp->mynode->gp_seq - rdp->rcu_iw_gp_seq);
 	falsepositive = rcu_is_gp_kthread_starving(NULL) &&
-			rcu_dynticks_in_eqs(ct_rcu_watching_cpu(cpu));
+			rcu_watching_snap_in_eqs(ct_rcu_watching_cpu(cpu));
 	rcuc_starved = rcu_is_rcuc_kthread_starving(rdp, &j);
 	if (rcuc_starved)
 		// Print signed value, as negative values indicate a probable bug.