rcu: Use rsp->expedited_wq instead of sync_rcu_preempt_exp_wq

Now that there is an ->expedited_wq waitqueue in each rcu_state structure,
there is no need for the sync_rcu_preempt_exp_wq global variable.  This
commit therefore substitutes ->expedited_wq for sync_rcu_preempt_exp_wq.
It also initializes ->expedited_wq only once at boot instead of at the
start of each expedited grace period.

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

1 files changed, 1 insertions, 1 deletions

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 775d36cc0050..53d66ebb4811 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3556,7 +3556,6 @@ void synchronize_sched_expedited(void)
         rcu_exp_gp_seq_start(rsp);
 
         /* Stop each CPU that is online, non-idle, and not us. */
-        init_waitqueue_head(&rsp->expedited_wq);
         atomic_set(&rsp->expedited_need_qs, 1); /* Extra count avoids race. */
         for_each_online_cpu(cpu) {
                 struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
@@ -4179,6 +4178,7 @@ static void __init rcu_init_one(struct rcu_state *rsp,
         }
 
         init_waitqueue_head(&rsp->gp_wq);
+        init_waitqueue_head(&rsp->expedited_wq);
         rnp = rsp->level[rcu_num_lvls - 1];
         for_each_possible_cpu(i) {
                 while (i > rnp->grphi)