rcu: Eliminate check_for_new_grace_period() wrapper function

One of the calls to check_for_new_grace_period() is now redundant due to
an immediately preceding call to note_gp_changes().  Eliminating this
redundant call leaves a single caller, which is simpler if inlined.
This commit therefore eliminates the redundant call and inlines the
body of check_for_new_grace_period() into the single remaining call site.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

kernel/rcutree.c

@@ -1307,26 +1307,6 @@ static void note_gp_changes(struct rcu_state *rsp, struct rcu_data *rdp)
 	raw_spin_unlock_irqrestore(&rnp->lock, flags);
 }
 
-/*
- * Did someone else start a new RCU grace period start since we last
- * checked?  Update local state appropriately if so.  Must be called
- * on the CPU corresponding to rdp.
- */
-static int
-check_for_new_grace_period(struct rcu_state *rsp, struct rcu_data *rdp)
-{
-	unsigned long flags;
-	int ret = 0;
-
-	local_irq_save(flags);
-	if (rdp->gpnum != rsp->gpnum) {
-		note_gp_changes(rsp, rdp);
-		ret = 1;
-	}
-	local_irq_restore(flags);
-	return ret;
-}
-
 /*
  * Do per-CPU grace-period initialization for running CPU.  The caller
  * must hold the lock of the leaf rcu_node structure corresponding to
@@ -1749,8 +1729,10 @@ static void
 rcu_check_quiescent_state(struct rcu_state *rsp, struct rcu_data *rdp)
 {
 	/* If there is now a new grace period, record and return. */
-	if (check_for_new_grace_period(rsp, rdp))
+	if (rdp->gpnum != rsp->gpnum) {
+		note_gp_changes(rsp, rdp);
 		return;
+	}
 
 	/*
 	 * Does this CPU still need to do its part for current grace period?
@@ -2302,7 +2284,6 @@ static void __call_rcu_core(struct rcu_state *rsp, struct rcu_data *rdp,
 
 		/* Are we ignoring a completed grace period? */
 		note_gp_changes(rsp, rdp);
-		check_for_new_grace_period(rsp, rdp);
 
 		/* Start a new grace period if one not already started. */
 		if (!rcu_gp_in_progress(rsp)) {