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authorPranith Kumar <bobby.prani@gmail.com>2014-07-08 17:46:50 -0400
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2014-09-07 16:18:07 -0700
commit4de376a1b14e32f550931274f06b571abc0f3d4b (patch)
tree2641f4598c5580d05652593f8c6bd4f601b94f4a /kernel/rcu/tree.c
parent11ed7f934cb807f26da09547b5946c2e534d1dac (diff)
rcu: Remove remaining read-modify-write ACCESS_ONCE() calls
Change the remaining uses of ACCESS_ONCE() so that each ACCESS_ONCE() either does a load or a store, but not both. Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu/tree.c')
-rw-r--r--kernel/rcu/tree.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 1b70cb6fbe3c..4b526ca46801 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1684,7 +1684,8 @@ static int rcu_gp_fqs(struct rcu_state *rsp, int fqs_state_in)
if (ACCESS_ONCE(rsp->gp_flags) & RCU_GP_FLAG_FQS) {
raw_spin_lock_irq(&rnp->lock);
smp_mb__after_unlock_lock();
- ACCESS_ONCE(rsp->gp_flags) &= ~RCU_GP_FLAG_FQS;
+ ACCESS_ONCE(rsp->gp_flags) =
+ ACCESS_ONCE(rsp->gp_flags) & ~RCU_GP_FLAG_FQS;
raw_spin_unlock_irq(&rnp->lock);
}
return fqs_state;
@@ -2505,7 +2506,8 @@ static void force_quiescent_state(struct rcu_state *rsp)
raw_spin_unlock_irqrestore(&rnp_old->lock, flags);
return; /* Someone beat us to it. */
}
- ACCESS_ONCE(rsp->gp_flags) |= RCU_GP_FLAG_FQS;
+ ACCESS_ONCE(rsp->gp_flags) =
+ ACCESS_ONCE(rsp->gp_flags) | RCU_GP_FLAG_FQS;
raw_spin_unlock_irqrestore(&rnp_old->lock, flags);
wake_up(&rsp->gp_wq); /* Memory barrier implied by wake_up() path. */
}