rcu: Use RCU_NOCB_WAKE rather than RCU_NOGP_WAKE

The RCU_NOGP_WAKE_NOT, RCU_NOGP_WAKE, and RCU_NOGP_WAKE_FORCE flags
are used to mediate wakeups for the no-CBs CPU kthreads.  The "NOGP"
really doesn't make any sense, so this commit does s/NOGP/NOCB/.

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

kernel/rcu/tree.h

@@ -312,9 +312,9 @@ struct rcu_data {
 };
 
 /* Values for nocb_defer_wakeup field in struct rcu_data. */
-#define RCU_NOGP_WAKE_NOT	0
-#define RCU_NOGP_WAKE		1
-#define RCU_NOGP_WAKE_FORCE	2
+#define RCU_NOCB_WAKE_NOT	0
+#define RCU_NOCB_WAKE		1
+#define RCU_NOCB_WAKE_FORCE	2
 
 #define RCU_JIFFIES_TILL_FORCE_QS (1 + (HZ > 250) + (HZ > 500))
 					/* For jiffies_till_first_fqs and */

kernel/rcu/tree_plugin.h

@@ -1901,7 +1901,7 @@ static void __call_rcu_nocb_enqueue(struct rcu_data *rdp,
 			trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
 					    TPS("WakeEmpty"));
 		} else {
-			WRITE_ONCE(rdp->nocb_defer_wakeup, RCU_NOGP_WAKE);
+			WRITE_ONCE(rdp->nocb_defer_wakeup, RCU_NOCB_WAKE);
 			/* Store ->nocb_defer_wakeup before ->rcu_urgent_qs. */
 			smp_store_release(this_cpu_ptr(&rcu_dynticks.rcu_urgent_qs), true);
 			trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
@@ -1915,7 +1915,7 @@ static void __call_rcu_nocb_enqueue(struct rcu_data *rdp,
 			trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
 					    TPS("WakeOvf"));
 		} else {
-			WRITE_ONCE(rdp->nocb_defer_wakeup, RCU_NOGP_WAKE_FORCE);
+			WRITE_ONCE(rdp->nocb_defer_wakeup, RCU_NOCB_WAKE_FORCE);
 			/* Store ->nocb_defer_wakeup before ->rcu_urgent_qs. */
 			smp_store_release(this_cpu_ptr(&rcu_dynticks.rcu_urgent_qs), true);
 			trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
@@ -2242,8 +2242,8 @@ static void do_nocb_deferred_wakeup(struct rcu_data *rdp)
 	if (!rcu_nocb_need_deferred_wakeup(rdp))
 		return;
 	ndw = READ_ONCE(rdp->nocb_defer_wakeup);
-	WRITE_ONCE(rdp->nocb_defer_wakeup, RCU_NOGP_WAKE_NOT);
-	wake_nocb_leader(rdp, ndw == RCU_NOGP_WAKE_FORCE);
+	WRITE_ONCE(rdp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT);
+	wake_nocb_leader(rdp, ndw == RCU_NOCB_WAKE_FORCE);
 	trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu, TPS("DeferredWake"));
 }