percpu-refcount: Use call_rcu_flush() for atomic switch
call_rcu() changes to save power will slow down percpu refcounter
per-CPU to atomic switch path. The primitive uses RCU when switching to
atomic mode.
The enqueued async callback wakes up waiters waiting in the
percpu_ref_switch_waitq. This will slow down the per-CPU refcount users
such as blk_pre_runtime_suspend().
Use the call_rcu_flush() API instead which reverts to the old behavior.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
1 file changed
