From: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Date: Thu, 19 Jan 2017 21:33:17 +0000 (-0800)
Subject: srcu: Consolidate batch checking into rcu_all_batches_empty()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=cc985822a0b6dbe68ad6cfa641b19c1d303ab455;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

srcu: Consolidate batch checking into rcu_all_batches_empty()

The srcu_reschedule() function invokes rcu_batch_empty() on each of
the four rcu_batch structures in the srcu_struct in question twice.
Given that this check will also be needed in cleanup_srcu_struct(), this
commit consolidates these four checks into a new rcu_all_batches_empty()
function.

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

diff --git a/kernel/rcu/srcu.c b/kernel/rcu/srcu.c
index ef3bcfb15b39..ba41a5d04b49 100644
--- a/kernel/rcu/srcu.c
+++ b/kernel/rcu/srcu.c
@@ -64,6 +64,17 @@ static inline bool rcu_batch_empty(struct rcu_batch *b)
 	return b->tail == &b->head;
 }
 
+/*
+ * Are all batches empty for the specified srcu_struct?
+ */
+static inline bool rcu_all_batches_empty(struct srcu_struct *sp)
+{
+	return rcu_batch_empty(&sp->batch_done) &&
+	       rcu_batch_empty(&sp->batch_check1) &&
+	       rcu_batch_empty(&sp->batch_check0) &&
+	       rcu_batch_empty(&sp->batch_queue);
+}
+
 /*
  * Remove the callback at the head of the specified rcu_batch structure
  * and return a pointer to it, or return NULL if the structure is empty.
@@ -619,15 +630,9 @@ static void srcu_reschedule(struct srcu_struct *sp)
 {
 	bool pending = true;
 
-	if (rcu_batch_empty(&sp->batch_done) &&
-	    rcu_batch_empty(&sp->batch_check1) &&
-	    rcu_batch_empty(&sp->batch_check0) &&
-	    rcu_batch_empty(&sp->batch_queue)) {
+	if (rcu_all_batches_empty(sp)) {
 		spin_lock_irq(&sp->queue_lock);
-		if (rcu_batch_empty(&sp->batch_done) &&
-		    rcu_batch_empty(&sp->batch_check1) &&
-		    rcu_batch_empty(&sp->batch_check0) &&
-		    rcu_batch_empty(&sp->batch_queue)) {
+		if (rcu_all_batches_empty(sp)) {
 			sp->running = false;
 			pending = false;
 		}