linux.git/Documentation/RCU, branch v5.15 Linux kernel source tree doc: Update stallwarn.rst with recent changes 2021-07-20T20:36:33+00:00 Paul E. McKenney paulmck@kernel.org 2021-07-14T18:46:55+00:00 99c0974ffeeab111bc709fc77b6900593e2e9078 This commit calls out the possibility of self-detected stalls, adds new messages, and calls out the use for stack traces. Reported-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> 
This commit calls out the possibility of self-detected stalls, adds new
messages, and calls out the use for stack traces.

Reported-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
rcu/doc: Add a quick quiz to explain further why we need smp_mb__after_unlock_lock() 2021-07-20T20:36:33+00:00 Frederic Weisbecker frederic@kernel.org 2021-06-10T15:50:29+00:00 c28adacc14e70e3260063e97ebb8dd984e6f7a07 Add some missing critical pieces of explanation to understand the need for full memory barriers throughout the whole grace period state machine, thanks to Paul's explanations. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Uladzislau Rezki <urezki@gmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> [ paulmck: Adjust code block per Akira Yokosawa. ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org> 
Add some missing critical pieces of explanation to understand the need
for full memory barriers throughout the whole grace period state machine,
thanks to Paul's explanations.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
[ paulmck: Adjust code block per Akira Yokosawa. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
docs: Fix a typo in Documentation/RCU/stallwarn.rst 2021-07-20T20:36:33+00:00 Haocheng Xie xiehaocheng.cn@gmail.com 2021-05-25T09:31:52+00:00 9984fd7e5e2f16cf867dba43ab9a4d123b91d3d3 Add the missing ')' in the documentation. Signed-off-by: Haocheng Xie <xiehaocheng.cn@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> 
Add the missing ')' in the documentation.

Signed-off-by: Haocheng Xie <xiehaocheng.cn@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Documentation/RCU: Fix nested inline markup 2021-07-20T20:36:33+00:00 Akira Yokosawa akiyks@gmail.com 2021-05-21T02:16:04+00:00 4966090849e96f4db1e115b77d2cfb68c2f73264 To avoid the ``foo`` markup inside the `bar`__ hyperlink marker, use the "replace" directive [1]. This should restore the intended appearance of the link. Tested with sphinx versions 1.7.9 and 2.4.4. [1]: https://docutils.sourceforge.io/docs/ref/rst/directives.html#replace Signed-off-by: Akira Yokosawa <akiyks@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> 
To avoid the ``foo`` markup inside the `bar`__ hyperlink marker,
use the "replace" directive [1].

This should restore the intended appearance of the link.

Tested with sphinx versions 1.7.9 and 2.4.4.

[1]: https://docutils.sourceforge.io/docs/ref/rst/directives.html#replace

Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Documentation/RCU: Fix emphasis markers 2021-07-20T20:36:33+00:00 Akira Yokosawa akiyks@gmail.com 2021-05-20T04:32:36+00:00 e3879ecd366a8ccc0ad7e36bf62692c16db360a1 "-foo-" does not work as emphasis in ReST markdown. Use "*foo*" instead. Signed-off-by: Akira Yokosawa <akiyks@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> 
"-foo-" does not work as emphasis in ReST markdown.
Use "*foo*" instead.

Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Merge branch 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu 2021-07-04T19:58:33+00:00 Linus Torvalds torvalds@linux-foundation.org 2021-07-04T19:58:33+00:00 28e92f990337b8b4c5fdec47667f8b96089c503e Pull RCU updates from Paul McKenney: - Bitmap parsing support for "all" as an alias for all bits - Documentation updates - Miscellaneous fixes, including some that overlap into mm and lockdep - kvfree_rcu() updates - mem_dump_obj() updates, with acks from one of the slab-allocator maintainers - RCU NOCB CPU updates, including limited deoffloading - SRCU updates - Tasks-RCU updates - Torture-test updates * 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (78 commits) tasks-rcu: Make show_rcu_tasks_gp_kthreads() be static inline rcu-tasks: Make ksoftirqd provide RCU Tasks quiescent states rcu: Add missing __releases() annotation rcu: Remove obsolete rcu_read_unlock() deadlock commentary rcu: Improve comments describing RCU read-side critical sections rcu: Create an unrcu_pointer() to remove __rcu from a pointer srcu: Early test SRCU polling start rcu: Fix various typos in comments rcu/nocb: Unify timers rcu/nocb: Prepare for fine-grained deferred wakeup rcu/nocb: Only cancel nocb timer if not polling rcu/nocb: Delete bypass_timer upon nocb_gp wakeup rcu/nocb: Cancel nocb_timer upon nocb_gp wakeup rcu/nocb: Allow de-offloading rdp leader rcu/nocb: Directly call __wake_nocb_gp() from bypass timer rcu: Don't penalize priority boosting when there is nothing to boost rcu: Point to documentation of ordering guarantees rcu: Make rcu_gp_cleanup() be noinline for tracing rcu: Restrict RCU_STRICT_GRACE_PERIOD to at most four CPUs rcu: Make show_rcu_gp_kthreads() dump rcu_node structures blocking GP ... 
Pull RCU updates from Paul McKenney:

 - Bitmap parsing support for "all" as an alias for all bits

 - Documentation updates

 - Miscellaneous fixes, including some that overlap into mm and lockdep

 - kvfree_rcu() updates

 - mem_dump_obj() updates, with acks from one of the slab-allocator
   maintainers

 - RCU NOCB CPU updates, including limited deoffloading

 - SRCU updates

 - Tasks-RCU updates

 - Torture-test updates

* 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (78 commits)
  tasks-rcu: Make show_rcu_tasks_gp_kthreads() be static inline
  rcu-tasks: Make ksoftirqd provide RCU Tasks quiescent states
  rcu: Add missing __releases() annotation
  rcu: Remove obsolete rcu_read_unlock() deadlock commentary
  rcu: Improve comments describing RCU read-side critical sections
  rcu: Create an unrcu_pointer() to remove __rcu from a pointer
  srcu: Early test SRCU polling start
  rcu: Fix various typos in comments
  rcu/nocb: Unify timers
  rcu/nocb: Prepare for fine-grained deferred wakeup
  rcu/nocb: Only cancel nocb timer if not polling
  rcu/nocb: Delete bypass_timer upon nocb_gp wakeup
  rcu/nocb: Cancel nocb_timer upon nocb_gp wakeup
  rcu/nocb: Allow de-offloading rdp leader
  rcu/nocb: Directly call __wake_nocb_gp() from bypass timer
  rcu: Don't penalize priority boosting when there is nothing to boost
  rcu: Point to documentation of ordering guarantees
  rcu: Make rcu_gp_cleanup() be noinline for tracing
  rcu: Restrict RCU_STRICT_GRACE_PERIOD to at most four CPUs
  rcu: Make show_rcu_gp_kthreads() dump rcu_node structures blocking GP
  ...
doc: Give XDP as example of non-obvious RCU reader/updater pairing 2021-06-24T17:41:14+00:00 Toke Høiland-Jørgensen toke@redhat.com 2021-06-24T16:05:53+00:00 e74c74f9e51deb725e72d129084ba8252d47222d This commit gives an example of non-obvious RCU reader/updater pairing in the guise of the XDP feature in networking, which calls BPF programs from network-driver NAPI (softirq) context. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210624160609.292325-4-toke@redhat.com 
This commit gives an example of non-obvious RCU reader/updater pairing
in the guise of the XDP feature in networking, which calls BPF programs
from network-driver NAPI (softirq) context.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210624160609.292325-4-toke@redhat.com
doc: Clarify and expand RCU updaters and corresponding readers 2021-06-24T17:41:14+00:00 Paul E. McKenney paulmck@kernel.org 2021-06-24T16:05:52+00:00 9a145c04a293933002ec288a4d6b4f370b59e4d1 This commit clarifies which primitives readers can use given that the corresponding updaters have made a specific choice. This commit also adds this information for the various RCU Tasks flavors. While in the area, it removes a paragraph that no longer applies in any straightforward manner. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210624160609.292325-3-toke@redhat.com 
This commit clarifies which primitives readers can use given that the
corresponding updaters have made a specific choice.  This commit also adds
this information for the various RCU Tasks flavors.  While in the area, it
removes a paragraph that no longer applies in any straightforward manner.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210624160609.292325-3-toke@redhat.com
doc: Fix diagram references in memory-ordering document 2021-05-10T22:39:19+00:00 Frederic Weisbecker frederic@kernel.org 2021-04-04T21:58:43+00:00 58d0db869d7ab8ca97b521f167022caa2c42cbe7 The three diagrams describing rcu_gp_init() all spuriously refer to the same figure, probably due to a copy/paste issue. This commit fixes these references. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> 
The three diagrams describing rcu_gp_init() all spuriously refer to
the same figure, probably due to a copy/paste issue.  This commit fixes
these references.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
doc: Fix statement of RCU's memory-ordering requirements 2021-05-10T22:39:19+00:00 Paul E. McKenney paulmck@kernel.org 2021-03-19T23:30:15+00:00 18389c4570211e10e94f4a2ce907d01397abc335 The sentence defining the relationship of accesses before a grace period to read-side accesses following that same grace period was missing a small word: "not". This commit therefore adds it. Reported-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> 
The sentence defining the relationship of accesses before a grace
period to read-side accesses following that same grace period was
missing a small word: "not".  This commit therefore adds it.

Reported-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>