rcu: Remove ACCESS_ONCE() from jiffies

Because jiffies is one of a very few variables marked "volatile", there
is no need to use ACCESS_ONCE() when accessing it.  This commit therefore
removes the redundant ACCESS_ONCE() wrappers.

Reported by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

2 files changed, 5 insertions, 5 deletions

diff --git a/kernel/rcu/torture.c b/kernel/rcu/torture.c
index ab7dd192a50b..022c5312b725 100644
--- a/kernel/rcu/torture.c
+++ b/kernel/rcu/torture.c
@@ -1352,7 +1352,7 @@ rcu_torture_shutdown(void *arg)
         unsigned long jiffies_snap;
 
         VERBOSE_PRINTK_STRING("rcu_torture_shutdown task started");
-        jiffies_snap = ACCESS_ONCE(jiffies);
+        jiffies_snap = jiffies;
         while (ULONG_CMP_LT(jiffies_snap, shutdown_time) &&
                !kthread_should_stop()) {
                 delta = shutdown_time - jiffies_snap;
@@ -1361,7 +1361,7 @@ rcu_torture_shutdown(void *arg)
                                  "rcu_torture_shutdown task: %lu jiffies remaining\n",
                                  torture_type, delta);
                 schedule_timeout_interruptible(delta);
-                jiffies_snap = ACCESS_ONCE(jiffies);
+                jiffies_snap = jiffies;
         }
         if (kthread_should_stop()) {
                 VERBOSE_PRINTK_STRING("rcu_torture_shutdown task stopping");
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 321feef0f5c0..73c3cd2b87ac 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -837,7 +837,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp,
          * to the next.  Only do this for the primary flavor of RCU.
          */
         if (rdp->rsp == rcu_state &&
-            ULONG_CMP_GE(ACCESS_ONCE(jiffies), rdp->rsp->jiffies_resched)) {
+            ULONG_CMP_GE(jiffies, rdp->rsp->jiffies_resched)) {
                 rdp->rsp->jiffies_resched += 5;
                 resched_cpu(rdp->cpu);
         }
@@ -847,7 +847,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp,
 
 static void record_gp_stall_check_time(struct rcu_state *rsp)
 {
-        unsigned long j = ACCESS_ONCE(jiffies);
+        unsigned long j = jiffies;
         unsigned long j1;
 
         rsp->gp_start = j;
@@ -1005,7 +1005,7 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp)
 
         if (rcu_cpu_stall_suppress || !rcu_gp_in_progress(rsp))
                 return;
-        j = ACCESS_ONCE(jiffies);
+        j = jiffies;
 
         /*
          * Lots of memory barriers to reject false positives.