tree 3a4e912e5c319329bc2a1e68b99ee041f0777150
parent 32bb1c79996069ef9e4e53b428050749f9841c3f
author Paul E. McKenney <paulmck@linux.vnet.ibm.com> 1436657085 -0700
committer Paul E. McKenney <paulmck@linux.vnet.ibm.com> 1437170346 -0700

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>