rcu: Add fastpath bypassing funnel locking

In the common case, there will be only one expedited grace period in
the system at a given time, in which case it is not helpful to use
funnel locking.  This commit therefore adds a fastpath that bypasses
funnel locking when the root ->exp_funnel_mutex is not held.

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

1 files changed, 1 insertions, 1 deletions

diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 543ba726396c..80d974df0ea0 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -493,7 +493,7 @@ struct rcu_state {
         /* End of fields guarded by barrier_mutex. */
 
         unsigned long expedited_sequence;       /* Take a ticket. */
-        atomic_long_t expedited_tryfail;        /* # acquisition failures. */
+        atomic_long_t expedited_workdone0;      /* # done by others #0. */
         atomic_long_t expedited_workdone1;      /* # done by others #1. */
         atomic_long_t expedited_workdone2;      /* # done by others #2. */
         atomic_long_t expedited_workdone3;      /* # done by others #3. */