summaryrefslogtreecommitdiff
path: root/Documentation/RCU/Design/Data-Structures/Data-Structures.html
AgeCommit message (Collapse)Author
2019-10-29docs: rcu: convert some articles from html to ReSTMauro Carvalho Chehab
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>
2019-03-26doc: Remove obsolete RCU update functions from RCU documentationPaul E. McKenney
Now that synchronize_rcu_bh, synchronize_rcu_bh_expedited, call_rcu_bh, rcu_barrier_bh, synchronize_sched, synchronize_sched_expedited, call_rcu_sched, rcu_barrier_sched, get_state_synchronize_sched, and cond_synchronize_sched are obsolete, let's remove them from the documentation aside from a small historical section. Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2018-11-12doc: rcu: Update description of gp_seq fields in rcu_dataJoel Fernandes (Google)
The rcu_state structure doesn't have a gp_seq_needed field. Update the description under rcu_data accordingly, to reflect this. Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: <kernel-team@android.com> Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2018-11-12doc: rcu: Better clarify the rcu_segcblist ->len fieldJoel Fernandes (Google)
An important note under the rcu_segcblist description could use a more detailed description. Especially explanation of the scenario where the ->head field may be temporarily NULL making it not wise to rely on it to determine if callbacks are associated with the rcu_segcblist. Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: <kernel-team@android.com> Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2018-11-12doc: rcu: Update Data-Structures for RCU flavor consolidationJoel Fernandes (Google)
This patch updates all Data-Structures document figures and text and removes some unwanted figures, to reflect the recent work Paul has been doing with consolidating all flavors of RCU. Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: <kernel-team@android.com> Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2018-11-12doc: Remove rcu_dynticks from Data-StructuresJoel Fernandes (Google)
rcu_dynticks was folded into rcu_data structure. Update the data structures RCU document accordingly. Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: <kernel-team@android.com> Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2018-11-08doc: Clarify RCU data-structure comment about rcu_tree fanoutJoel Fernandes (Google)
RCU Data-Structures document describes a trick to test RCU with small number of CPUs but with a taller tree. It wasn't immediately clear how the document arrived at 16 CPUs which also requires setting the FANOUT_LEAF to 2 instead of the default of 16. This commit therefore provides the needed clarification. Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: <kernel-team@android.com> Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2018-08-30doc: Update removal of RCU-bh/sched update machineryPaul E. McKenney
The RCU-bh update API is now defined in terms of that of RCU-bh and RCU-sched, so this commit updates the documentation accordingly. In addition, although RCU-sched persists in !PREEMPT kernels, in the PREEMPT case its update API is now defined in terms of that of RCU-preempt, so this commit also updates the documentation accordingly. While in the area, this commit removes the documentation for the now-obsolete synchronize_rcu_mult() and clarifies the Tasks RCU documentation. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-08-29doc: Improve rcu_dynticks::dynticks documentationJoel Fernandes (Google)
The very useful RCU Data-Structures describes that the dynticks counter of the rcu_dynticks data structure is incremented when we transitions to or from dynticks-idle mode. However it doesn't mention that it is also incremented due to transitions to and from user mode which for dynticks purposes is an extended quiescent state. I found this with tracing calls to rcu_dynticks_eqs_enter which can also happen from rcu_user_enter. Lets add this information to the Data-Structures document. Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12doc: Update data-structure documentation for ->gp_seqPaul E. McKenney
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-12-11Merge branches 'cond_resched.2017.12.04a', 'dyntick.2017.11.28a', ↵Paul E. McKenney
'fixes.2017.12.11a', 'srbd.2017.12.05a' and 'torture.2017.12.11a' into HEAD cond_resched.2017.12.04a: Convert cond_resched_rcu_qs() to cond_resched() dyntick.2017.11.28a: Make RCU dynticks handle interrupts from NMI fixes.2017.12.11a: Miscellaneous fixes srbd.2017.12.05a: Remove now-redundant smp_read_barrier_depends() torture.2017.12.11a: Torture-testing update
2017-12-04doc: Eliminate cond_resched_rcu_qs() in favor of cond_resched()Paul E. McKenney
Now that cond_resched() also provides RCU quiescent states when needed, it can be used in place of cond_resched_rcu_qs(). This commit therefore documents this change. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-11-28doc: Update dyntick-idle design documentation for NMI/irq consolidationPaul E. McKenney
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-04-21Merge branches 'doc.2017.04.12a', 'fixes.2017.04.19a' and 'srcu.2017.04.21a' ↵Paul E. McKenney
into HEAD doc.2017.04.12a: Documentation updates fixes.2017.04.19a: Miscellaneous fixes srcu.2017.04.21a: Parallelize SRCU callback handling
2017-04-18rcu: Place guard on rcu_all_qs() and rcu_note_context_switch() actionsPaul E. McKenney
The rcu_all_qs() and rcu_note_context_switch() do a series of checks, taking various actions to supply RCU with quiescent states, depending on the outcomes of the various checks. This is a bit much for scheduling fastpaths, so this commit creates a separate ->rcu_urgent_qs field in the rcu_dynticks structure that acts as a global guard for these checks. Thus, in the common case, rcu_all_qs() and rcu_note_context_switch() check the ->rcu_urgent_qs field, find it false, and simply return. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org>
2017-04-18rcu: Eliminate flavor scan in rcu_momentary_dyntick_idle()Paul E. McKenney
The rcu_momentary_dyntick_idle() function scans the RCU flavors, checking that one of them still needs a quiescent state before doing an expensive atomic operation on the ->dynticks counter. However, this check reduces overhead only after a rare race condition, and increases complexity. This commit therefore removes the scan and the mechanism enabling the scan. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-04-18rcu: Pull rcu_qs_ctr into rcu_dynticks structurePaul E. McKenney
The rcu_qs_ctr variable is yet another isolated per-CPU variable, so this commit pulls it into the pre-existing rcu_dynticks per-CPU structure. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-04-18rcu: Pull rcu_sched_qs_mask into rcu_dynticks structurePaul E. McKenney
The rcu_sched_qs_mask variable is yet another isolated per-CPU variable, so this commit pulls it into the pre-existing rcu_dynticks per-CPU structure. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-04-12doc: Update RCU data-structure documentation for rcu_segcblistPaul E. McKenney
The rcu_segcblist data structure, which contains segmented lists of RCU callbacks, was recently added. This commit updates the documentation accordingly. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-01-14doc: Quick-Quiz answers are now inlinePaul E. McKenney
Now that quick-quiz answers are inline, there is no separate section containing those answers. This commit therefore removes the dangling reference from the RCU data-structures design documentation. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2016-04-19documentation: Add documentation for RCU's major data structuresPaul E. McKenney
This commit adds documentation for RCU's major data structures, including rcu_state, rcu_node, rcu_data, rcu_dynticks, and rcu_head. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>