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>
Pull RCU updates from Paul E. McKenney:
- Documentation updates.
- Miscellaneous fixes.
- kfree_rcu() updates: Addition of mem_dump_obj() to provide allocator return
addresses to more easily locate bugs. This has a couple of RCU-related commits,
but is mostly MM. Was pulled in with akpm's agreement.
- Per-callback-batch tracking of numbers of callbacks,
which enables better debugging information and smarter
reactions to large numbers of callbacks.
- The first round of changes to allow CPUs to be runtime switched from and to
callback-offloaded state.
- CONFIG_PREEMPT_RT-related changes.
- RCU CPU stall warning updates.
- Addition of polling grace-period APIs for SRCU.
- Torture-test and torture-test scripting updates, including a "torture everything"
script that runs rcutorture, locktorture, scftorture, rcuscale, and refscale.
Plus does an allmodconfig build.
Signed-off-by: Ingo Molnar <mingo@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>
The PREEMPT_RT wiki moved from kernel.org to the Linux Foundation wiki.
The kernel.org wiki is read only.
This commit therefore updates the URL of the active PREEMPT_RT wiki.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit adds requirements documentation for the
get_state_synchronize_srcu(), start_poll_synchronize_srcu(), and
poll_state_synchronize_srcu() functions.
Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Back in the day, RCU_INIT_POINTER() was the only way to avoid
memory-barrier instructions while storing NULL to an RCU-protected
pointer. Fortunately, in 2016, rcu_assign_pointer() started checking for
compile-time NULL pointers and omitting the memory-barrier instructions in
that case. Unfortunately, RCU's Requirements.rst document was not updated
accordingly. This commit therefore at long last carries out that update.
Fixes: 3a37f7275c ("rcu: No ordering for rcu_assign_pointer() of NULL")
Link: https://lore.kernel.org/lkml/20201209230755.GV7338@casper.infradead.org/
Reported-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
It appears the Compaq link moved to a machine at HP for a while
after the merger of the two, but that doesn't work either. A search
of HP for "wiz_2637" (w and w/o html suffix) comes up empty.
Since the references aren't critical to the documents we remove them.
Also, the lkml.kernel.org/g links have been broken for ages, so replace
them with lore.kernel.org/r links - standardize on lore for all links too.
Note that we put off fixing these 4y ago - presumably thinking that a
treewide fixup was pending. Probably safe to go fix the RCU ones now.
https://lore.kernel.org/r/20160915144926.GD10850@linux.vnet.ibm.com/
Cc: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
synchronize_rcu_bh(), synchronize_rcu_bh_expedited(), call_rcu_bh(),
rcu_barrier_bh(), synchronize_sched(), synchronize_rcu_sched_expedited(),
call_rcu_sched(), and rcu_barrier_sched() no longer exist, so this
commit removes mention of them.
Reported-by: Joel Fernandes <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The docbook system has learned that "()" designates a function, so
this commit removes the no-longer-needed "``" to improve readability
of the raw .rst file.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
[ paulmck: Apply Stephen Rothwell feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
During the process of converting the documentation to reST, some links
were converted using the following wrong syntax (and sometimes using %20
instead of spaces):
`Display text <#section-name-in-html>`__
This syntax isn't valid according to the docutils' spec [1], but more
importantly, it is specific to HTML, since it uses '#' to link to an
HTML anchor.
The right syntax would instead use a docutils hyperlink reference as the
embedded URI to point to the section [2], that is:
`Display text <Section Name_>`__
This syntax works in both HTML and PDF.
The LaTeX toolchain doesn't mind the HTML anchor syntax when generating
the pdf documentation (make pdfdocs), that is, the build succeeds but
the links don't work, but that syntax causes errors when trying to build
using the not-yet-merged rst2pdf:
ValueError: format not resolved, probably missing URL scheme or undefined destination target for 'Forcing%20Quiescent%20States'
So, use the correct syntax in order to have it work in all different
output formats.
[1]: https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html#reference-names
[2]: https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html#embedded-uris-and-aliases
Fixes: ccc9971e21 ("docs: rcu: convert some articles from html to ReST")
Fixes: c8cce10a62 ("docs: Fix the reference labels in Locking.rst")
Fixes: e548cdeffc ("docs-rst: convert kernel-locking to ReST")
Fixes: 7ddedebb03 ("ALSA: doc: ReSTize writing-an-alsa-driver document")
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@protonmail.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/20201228144537.135353-1-nfraprado@protonmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
As warned by Sphinx:
.../Documentation/RCU/Design/Requirements/Requirements.rst:1959: WARNING: Unexpected indentation.
The list block is missing a space before it, making Sphinx to get
it wrong. This commit therefore adds the missing space characters.
Fixes: 2a721e5f0b2c ("docs: Update RCU's hotplug requirements with a bit about design")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The rcu_barrier() section of the "Hotplug CPU" section discusses
deadlocks, however the description of deadlocks other than those involving
rcu_barrier() is rather incomplete.
This commit therefore continues the section by describing how RCU's
design handles CPU hotplug in a deadlock-free way.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Drop the doubled words "to" and "for".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: rcu@vger.kernel.org
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The [smp_]read_barrier_depends() barrier macros no longer exist as
part of the Linux memory model, so remove all references to them from
the Documentation/ directory.
Although this is fairly mechanical on the whole, we drop the "CACHE
COHERENCY" section entirely from 'memory-barriers.txt' as it doesn't
make any sense now that the dependency barriers have been removed.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Protecting the code in a trampoline can also require protecting a
number of instructions prior to actually entering the trampoline.
For example, these earlier instructions might be computing the address
of the trampoline. This commit therefore updates RCU's requirements to
record this for posterity.
Link: https://lore.kernel.org/lkml/20200511154824.09a18c46@gandalf.local.home/
Reported-by: Lai Jiangshan <jiangshanlai@gmail.com>
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The scheduler is currently required to hold rq/pi locks across the entire
RCU read-side critical section or not at all. This is inconvenient and
leaves traps for the unwary, including the author of this commit.
But now that excessively long grace periods enable scheduling-clock
interrupts for holdout nohz_full CPUs, the nohz_full rescue logic in
rcu_read_unlock_special() can be dispensed with. In other words, the
rcu_read_unlock_special() function can refrain from doing wakeups unless
such wakeups are guaranteed safe.
This commit therefore avoids unsafe wakeups, freeing the scheduler to
hold rq/pi locks across rcu_read_unlock() even if the corresponding RCU
read-side critical section might have been preempted. This commit also
updates RCU's requirements documentation.
This commit is inspired by a patch from Lai Jiangshan:
https://lore.kernel.org/lkml/20191102124559.1135-2-laijs@linux.alibaba.com
This commit is further intended to be a step towards his goal of permitting
the inlining of RCU-preempt's rcu_read_lock() and rcu_read_unlock().
Cc: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This restores docs back in ReST format.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
[ paulmck: Added Joel's SoB per Stephen Rothwell feedback. ]
[ paulmck: Joel approved via private email. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This restores docs back in ReST format.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
[ paulmck: Added Joel's SoB per Stephen Rothwell feedback. ]
[ paulmck: Joel approved via private email. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Mauro's auto conversion broken these links, fix them.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
There are 4 RCU articles that are written on html format.
The way they are, they can't be part of the Linux Kernel
documentation body nor share the styles and pdf output.
So, convert them to ReST format.
This way, make htmldocs and make pdfdocs will produce a
documentation output that will be like the original ones, but
will be part of the Linux Kernel documentation body.
Part of the conversion was done with the help of pandoc, but
the result had some broken things that had to be manually
fixed.
Following are manual changes Mauro made when doing the automatic conversion:
Quoting from: https://lore.kernel.org/rcu/20190726154550.5eeae294@coco.lan/
> > At least the pandoc's version I used here has a bug: its conversion
> > from html to ReST on those files only start after a <body> tag - or
> > when the first quiz table starts. I only discovered that adding a
> > <body> at the beginning of the file solve this book at the last
> > conversions.
> >
> > So, for most html->ReST conversions, I manually converted the first
> > part of the document, basically stripping html paragraph tags and
> > by replacing highlights by the ReST syntax.
> >
> > Also, all the quiz tables seem to assume some javascript macro or
> > css style that would be hiding the answer part until the mouse moves
> > to it. Such macro/css was not there at the kernel tree. So, the quiz
> > answers have the same color as the background, making them invisible.
> > Even if we had such macro/css, this is not portable for pdf/LaTeX output
> > (and I'm not sure if this would work with ePub).
> >
> > So, I ended by manually doing the table conversion.
> >
> > Finally, I double-checked if the conversions ended ok, addressing any
> > issues that might have heppened.
> >
> > So, after both automatic conversion and manual fixes, I opened both the
> > html files produced by Sphinx and the original ones and compared them
> > line per line (except for the indexes, as Sphinx produces them
> > automatically), in order to see if all information from the original
> > files will be there on a format close to what we have on other ReST
> > files, fixing any pending issues if any.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Akira Yokosawa
Ingo Molnar
Paul E. McKenney
Sebastian Andrzej Siewior
Paul Gortmaker
Nícolas F. R. A. Prado
Mauro Carvalho Chehab
Joel Fernandes (Google)
Randy Dunlap
Linus Torvalds
Will Deacon
Mauro Carvalho Chehab