On Tue, Nov 05, 2019 at 08:08:50AM +0200, Jani Nikula wrote: > On Mon, 04 Nov 2019, Amol Grover <frextrite@xxxxxxxxx> wrote: > > On Mon, Nov 04, 2019 at 05:15:34PM +0200, Jani Nikula wrote: > >> On Mon, 04 Nov 2019, Amol Grover <frextrite@xxxxxxxxx> wrote: > >> > Convert RCU API method text to sub-headings and > >> > add hyperlink and superscript to 2 literary notes > >> > under rcu_dereference() section > >> > > >> > Signed-off-by: Amol Grover <frextrite@xxxxxxxxx> > >> > --- > >> > Documentation/RCU/whatisRCU.rst | 34 +++++++++++++++++++++++++++------ > >> > 1 file changed, 28 insertions(+), 6 deletions(-) > >> > > >> > diff --git a/Documentation/RCU/whatisRCU.rst b/Documentation/RCU/whatisRCU.rst > >> > index ae40c8bcc56c..3cf6e17d0065 100644 > >> > --- a/Documentation/RCU/whatisRCU.rst > >> > +++ b/Documentation/RCU/whatisRCU.rst > >> > @@ -150,6 +150,7 @@ later. See the kernel docbook documentation for more info, or look directly > >> > at the function header comments. > >> > > >> > rcu_read_lock() > >> > +^^^^^^^^^^^^^^^ > >> > > >> > void rcu_read_lock(void); > >> > > >> > @@ -164,6 +165,7 @@ rcu_read_lock() > >> > longer-term references to data structures. > >> > > >> > rcu_read_unlock() > >> > +^^^^^^^^^^^^^^^^^ > >> > > >> > void rcu_read_unlock(void); > >> > > >> > @@ -172,6 +174,7 @@ rcu_read_unlock() > >> > read-side critical sections may be nested and/or overlapping. > >> > > >> > synchronize_rcu() > >> > +^^^^^^^^^^^^^^^^^ > >> > > >> > void synchronize_rcu(void); > >> > > >> > @@ -225,6 +228,7 @@ synchronize_rcu() > >> > checklist.txt for some approaches to limiting the update rate. > >> > > >> > rcu_assign_pointer() > >> > +^^^^^^^^^^^^^^^^^^^^ > >> > > >> > void rcu_assign_pointer(p, typeof(p) v); > >> > > >> > @@ -245,6 +249,7 @@ rcu_assign_pointer() > >> > the _rcu list-manipulation primitives such as list_add_rcu(). > >> > > >> > rcu_dereference() > >> > +^^^^^^^^^^^^^^^^^ > >> > > >> > typeof(p) rcu_dereference(p); > >> > > >> > @@ -279,8 +284,10 @@ rcu_dereference() > >> > if an update happened while in the critical section, and incur > >> > unnecessary overhead on Alpha CPUs. > >> > > >> > +.. _back_to_1: > >> > + > >> > Note that the value returned by rcu_dereference() is valid > >> > - only within the enclosing RCU read-side critical section [1]. > >> > + only within the enclosing RCU read-side critical section |cs_1|. > >> > For example, the following is -not- legal:: > >> > > >> > rcu_read_lock(); > >> > @@ -298,15 +305,27 @@ rcu_dereference() > >> > it was acquired is just as illegal as doing so with normal > >> > locking. > >> > > >> > +.. _back_to_2: > >> > + > >> > As with rcu_assign_pointer(), an important function of > >> > rcu_dereference() is to document which pointers are protected by > >> > RCU, in particular, flagging a pointer that is subject to changing > >> > at any time, including immediately after the rcu_dereference(). > >> > And, again like rcu_assign_pointer(), rcu_dereference() is > >> > typically used indirectly, via the _rcu list-manipulation > >> > - primitives, such as list_for_each_entry_rcu() [2]. > >> > + primitives, such as list_for_each_entry_rcu() |entry_2|. > >> > + > >> > +.. |cs_1| raw:: html > >> > >> Please don't use raw. It's ugly and error prone. We have some raw output > >> for latex, but this would be the first for html. > >> > >> What are you trying to achieve? > > > > Hi Jani, > > While going through the documentation I encountered a few footnotes (numbers > > [1] and [2]) which referenced the actual footnote somewhere below the text. > > They were particularly not straight-forward to find hence I decided to > > link them to the footnote text which could be done using inline markup. > > Then I tried to make them more appealing by converting to super-scripts > > (the way they look like in books and websites). However, nested inline > > markup is not yet possible in reST hence I went with the html way to > > achieve the same. Too much? > > I suggest you use rst footnote markup. It's less of an eye sore in the > rst source, but provides you with the links in the generated output. And > typically would be superscript. In particular "autonumber labels" might > fit the bill. [1][2] > > BR, > Jani. > > > [1] http://docutils.sourceforge.net/docs/user/rst/quickref.html#footnotes > [2] http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html#footnotes > > > > > > Thank you > > Amol > > > >> > >> BR, > >> Jani. > >> > >> > + > >> > + <a href="#cs"><sup>[1]</sup></a> > >> > + > >> > +.. |entry_2| raw:: html > >> > > >> > - [1] The variant rcu_dereference_protected() can be used outside > >> > + <a href="#entry"><sup>[2]</sup></a> > >> > + > >> > +.. _cs: > >> > + > >> > + \ :sup:`[1]`\ The variant rcu_dereference_protected() can be used outside > >> > of an RCU read-side critical section as long as the usage is > >> > protected by locks acquired by the update-side code. This variant > >> > avoids the lockdep warning that would happen when using (for > >> > @@ -317,15 +336,18 @@ rcu_dereference() > >> > a lockdep expression to indicate which locks must be acquired > >> > by the caller. If the indicated protection is not provided, > >> > a lockdep splat is emitted. See Documentation/RCU/Design/Requirements/Requirements.rst > >> > - and the API's code comments for more details and example usage. > >> > + and the API's code comments for more details and example usage. :ref:`back <back_to_1>` > >> > + > >> > + > >> > +.. _entry: > >> > > >> > - [2] If the list_for_each_entry_rcu() instance might be used by > >> > + \ :sup:`[2]`\ If the list_for_each_entry_rcu() instance might be used by > >> > update-side code as well as by RCU readers, then an additional > >> > lockdep expression can be added to its list of arguments. > >> > For example, given an additional "lock_is_held(&mylock)" argument, > >> > the RCU lockdep code would complain only if this instance was > >> > invoked outside of an RCU read-side critical section and without > >> > - the protection of mylock. > >> > + the protection of mylock. :ref:`back <back_to_2>` > >> > > >> > The following diagram shows how each API communicates among the > >> > reader, updater, and reclaimer. > >> > >> -- > >> Jani Nikula, Intel Open Source Graphics Center > > -- > Jani Nikula, Intel Open Source Graphics Center Thank you for the feedback Paul and Jani! Sent the updated patch at https://lore.kernel.org/lkml/20191105073340.GA3682@workstation-kernel-dev/ with the requested changes. Thank you Amol
