docs: RCU: Convert checklist.txt to ReST

.. SPDX-License-Identifier: GPL-2.0

================================

Review Checklist for RCU Patches

================================

This document contains a checklist for producing and reviewing patches

	__rcu sparse checks to validate your RCU code.	These can help

	find problems as follows:

	CONFIG_PROVE_LOCKING: check that accesses to RCU-protected data

	CONFIG_PROVE_LOCKING:

		check that accesses to RCU-protected data

		structures are carried out under the proper RCU

		read-side critical section, while holding the right

		combination of locks, or whatever other conditions

		are appropriate.

	CONFIG_DEBUG_OBJECTS_RCU_HEAD: check that you don't pass the

	CONFIG_DEBUG_OBJECTS_RCU_HEAD:

		check that you don't pass the

		same object to call_rcu() (or friends) before an RCU

		grace period has elapsed since the last time that you

		passed that same object to call_rcu() (or friends).

	__rcu sparse checks: tag the pointer to the RCU-protected data

	__rcu sparse checks:

		tag the pointer to the RCU-protected data

		structure with __rcu, and sparse will warn you if you

		access that pointer without the services of one of the

		variants of rcu_dereference().

	You instead need to use one of the barrier functions:

	o	call_rcu() -> rcu_barrier()

	o	call_srcu() -> srcu_barrier()

	-	call_rcu() -> rcu_barrier()

	-	call_srcu() -> srcu_barrier()

	However, these barrier functions are absolutely -not- guaranteed

	to wait for a grace period.  In fact, if there are no call_rcu()

.. SPDX-License-Identifier: GPL-2.0

.. _rcu_concepts:

============

   :maxdepth: 3

   arrayRCU

   checklist

   rcubarrier

   rcu_dereference

   whatisRCU