tree 2f3aab93d09c2eb89b2ba3466e9d43cf79a8c3bb
parent ed8f6fb247785d98ffe6babcf93b7bedd2c88fd8
author Joel Fernandes (Google) <joel@joelfernandes.org> 1538781490 -0700
committer Paul E. McKenney <paulmck@linux.ibm.com> 1542041785 -0800

doc: rcu: Update core and full API in whatisRCU

RCU consolidation effort causes the update side of the RCU API to
be consistent across all the 3 RCU flavors (normal, sched, bh). This
commit therefore updates the full API in the whatisRCU document, thus
encouraging people to use the consolidated RCU update API instead of
the old RCU-bh and RCU-sched update APIs.

Also rcu_dereference is documented to be the same for all 3 mechanisms
(even before the consolidation), however its actually different - as
using the right rcu_dereference primitive (such as rcu_dereference_bh
for bh) is needed to make lock debugging work correctly. This update
also corrects that.

Also, add local_bh_disable() and local_bh_enable() as softirq
protection primitives and correct a grammar error in a quiz answer.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>