blackbird-obmc-linux/Documentation/RCU/Design/Data-Structures, branch dev-5.0-raptor-04-16-2019

doc: rcu: Update description of gp_seq fields in rcu_data

2018-11-12T16:56:25+00:00

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) Cc: Signed-off-by: Paul E. McKenney

doc: rcu: Better clarify the rcu_segcblist ->len field

2018-11-12T16:56:25+00:00

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) Cc: Signed-off-by: Paul E. McKenney

doc: rcu: Update Data-Structures for RCU flavor consolidation

2018-11-12T16:56:25+00:00

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) Cc: Signed-off-by: Paul E. McKenney

doc: Remove rcu_dynticks from Data-Structures

2018-11-12T16:49:05+00:00

rcu_dynticks was folded into rcu_data structure. Update the data structures RCU document accordingly. Signed-off-by: Joel Fernandes (Google) Cc: Signed-off-by: Paul E. McKenney

doc: Clarify RCU data-structure comment about rcu_tree fanout

2018-11-09T05:44:41+00:00

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) Cc: Signed-off-by: Paul E. McKenney

doc: Update removal of RCU-bh/sched update machinery

2018-08-30T17:59:48+00:00

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

doc: Improve rcu_dynticks::dynticks documentation

2018-08-29T15:54:30+00:00

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) Signed-off-by: Paul E. McKenney

doc: Update data-structure documentation for ->gp_seq

2018-07-12T22:38:49+00:00

Signed-off-by: Paul E. McKenney

Merge branches 'cond_resched.2017.12.04a', 'dyntick.2017.11.28a', 'fixes.2017.12.11a', 'srbd.2017.12.05a' and 'torture.2017.12.11a' into HEAD

2017-12-11T17:21:58+00:00

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

doc: Eliminate cond_resched_rcu_qs() in favor of cond_resched()

2017-12-04T18:28:59+00:00

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