rcu: Add memory barriers for NOCB leader wakeup
authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Sat, 29 Apr 2017 03:11:09 +0000 (20:11 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 21 Jul 2017 04:59:10 +0000 (06:59 +0200)
commitc5e9bfe6db68afd6fc477acbc827a07e9204fc7d
tree7afc21babf49e2b1b084f682bd622d64bb74c384
parent101cbdea05f786852e37cf88ff0c03ac45883d60
rcu: Add memory barriers for NOCB leader wakeup

commit 6b5fc3a1331810db407c9e0e673dc1837afdc9d0 upstream.

Wait/wakeup operations do not guarantee ordering on their own.  Instead,
either locking or memory barriers are required.  This commit therefore
adds memory barriers to wake_nocb_leader() and nocb_leader_wait().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Krister Johansen <kjlx@templeofstupid.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernel/rcu/tree_plugin.h