This patch adds LWN articles about RCU APIs which were released in 2019.
Also, HTTP URLs are replaced by HTTPS.
Signed-off-by: Shao-Tse Hung <ccs100203@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Because the SLAB_TYPESAFE_BY_RCU code does not zero pages that are
to be broken up into slabs, the memory returned by kmem_cache_alloc()
must be fully initialized, including any spinlocks included in the newly
allocated structure. This means that readers attempting to look up an
SLAB_TYPESAFE_BY_RCU object must use a reference-counting approach.
A spinlock may be acquired only after a reference is obtained, which
prevents that object from being passed to kmem_struct_free(), but only
while that reference continues to be held.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The rcu_access_pointer() macro does not consult lockdep by design because
it is intended to be used outside of RCU read-side critical sections.
This commit therefore makes a separate list for it in whatisRCU.rst.
Similarly, RCU_LOCKDEP_WARN(), rcu_sleep_check(), and RCU_NONIDLE()
do not do anything with pointer access. This commit therefore creates
a separate utility-API list for them.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The RCU documentation contains old-style cross references which
do not follow the best practices outlined in doc-guide/sphinx.rst.
In addition, some of the cross references use URLs that should be replaced
by pathnames.
Update all of these cross references and adjust the surrounding words.
Summary of changes:
- out-of-date plaintext file names (*.txt) -> *.rst
- references by :ref: tags -> path names of *.rst
* use relative paths to .rst files under the RCU/ subdirectory
* use abs paths of Documentation/xxx for other .rst files
- references by URL under https://www.kernel.org/ -> paths of *.rst
- adjust surrounding words of some of updated references.
Note:
The automarkup.py script interprets references via "*.txt" as if they
were via "*.rst", so the *.txt -> *.rst changes should be regarded as
cleanups rather than bug fixes.
Cc: rcu@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The reader-writer-lock analogy is a useful way to think about RCU, but
it is not always applicable. It is useful to have other analogies to
work with, and particularly to emphasise that no single analogy is
perfect.
This patch add a "RCU as reference count" to the "what is RCU" document.
See https://lwn.net/Articles/872559/
[ paulmck: Apply Akira Yokosawa feedback. ]
Reviewed-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT.
Both PREEMPT and PREEMPT_RT require the same functionality which today
depends on CONFIG_PREEMPT.
Update the documents and mention CONFIG_PREEMPTION. Spell out
CONFIG_PREEMPT_RT (instead PREEMPT_RT) since it is an option now.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit updates the documented API of call_rcu() to use the
rcu_callback_t typedef instead of the open-coded function definition.
Signed-off-by: Hui Su <sh_def@163.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This patch updates the list of RCU API in whatisRCU.rst.
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik04@gmail.com>
Tested-by: Amol Grover <frextrite@gmail.com>
Tested-by: Phong Tran <tranmanphong@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Shao-Tse Hung