Hello!

This series re-implements RCU Tasks Trace in terms of SRCU-fast,
reducing the size of the Linux-kernel RCU implementation by several
hundred lines of code.  It also removes a conditional branch from the
srcu_read_lock_fast() implementation in order to make SRCU-fast a
bit more fastpath-friendly.  The patches are as follows:

1.	Re-implement RCU Tasks Trace in terms of SRCU-fast.

2.	Remove unused ->trc_ipi_to_cpu and ->trc_blkd_cpu from
	task_struct.

3.	Remove ->trc_blkd_node from task_struct.

4.	Remove ->trc_holdout_list from task_struct.

5.	Remove rcu_tasks_trace_qs() and the functions that it calls.

6.	context_tracking: Remove
	rcu_task_trace_heavyweight_{enter,exit}().

7.	Remove ->trc_reader_special from task_struct.

8.	Remove now-empty RCU Tasks Trace functions and calls to them.

9.	Remove unused rcu_tasks_trace_lazy_ms and trc_stall_chk_rdr
	struct.

10.	Remove now-empty show_rcu_tasks_trace_gp_kthread() function.

11.	Remove now-empty rcu_tasks_trace_get_gp_data() function.

12.	Remove now-empty rcu_tasks_trace_torture_stats_print() function.

13.	Remove now-empty get_rcu_tasks_trace_gp_kthread() function.

14.	Move rcu_tasks_trace_srcu_struct out of #ifdef
	CONFIG_TASKS_RCU_GENERIC.

15.	Add noinstr-fast rcu_read_{,un}lock_tasks_trace() APIs.

16.	Remove now-unused rcu_task_ipi_delay and TASKS_TRACE_RCU_READ_MB.

17.	Create a DEFINE_SRCU_FAST().

18.	Use smp_mb() only when necessary in RCU Tasks Trace readers.

19.	Update Requirements.rst for RCU Tasks Trace.

20.	Deprecate rcu_read_{,un}lock_trace().

21.	Mark diagnostic functions as notrace.

22.	Guard __DECLARE_TRACE() use of __DO_TRACE_CALL() with SRCU-fast.

23.	Create an srcu_expedite_current() function.

24.	Test srcu_expedite_current().

25.	Create an rcu_tasks_trace_expedite_current() function.

26.	Test rcu_tasks_trace_expedite_current().

27.	Make DEFINE_SRCU_FAST() available to modules.

28.	Make SRCU-fast available to heap srcu_struct structures.

29.	Make grace-period determination use ssp->srcu_reader_flavor.

30.	Exercise DEFINE_STATIC_SRCU_FAST() and init_srcu_struct_fast().

31.	Exercise DEFINE_STATIC_SRCU_FAST() and init_srcu_struct_fast().

32.	Require special srcu_struct define/init for SRCU-fast readers.

33.	Make SRCU-fast readers enforce use of SRCU-fast definition/init.

34.	Update for SRCU-fast definitions and initialization.

						Thanx, Paul

------------------------------------------------------------------------

 Documentation/RCU/Design/Requirements/Requirements.rst   |   33 
 Documentation/admin-guide/kernel-parameters.txt          |    7 
 b/Documentation/RCU/Design/Requirements/Requirements.rst |   12 
 b/Documentation/RCU/checklist.rst                        |   12 
 b/Documentation/RCU/whatisRCU.rst                        |    3 
 b/Documentation/admin-guide/kernel-parameters.txt        |    8 
 b/include/linux/notifier.h                               |    2 
 b/include/linux/rcupdate.h                               |   26 
 b/include/linux/rcupdate_trace.h                         |  107 +-
 b/include/linux/sched.h                                  |    1 
 b/include/linux/srcu.h                                   |   16 
 b/include/linux/srcutiny.h                               |    1 
 b/include/linux/srcutree.h                               |   20 
 b/include/linux/tracepoint.h                             |   45 -
 b/include/trace/perf.h                                   |    4 
 b/include/trace/trace_events.h                           |    4 
 b/init/init_task.c                                       |    1 
 b/kernel/context_tracking.c                              |   20 
 b/kernel/fork.c                                          |    1 
 b/kernel/rcu/Kconfig                                     |    2 
 b/kernel/rcu/rcu.h                                       |    5 
 b/kernel/rcu/rcuscale.c                                  |    6 
 b/kernel/rcu/rcutorture.c                                |    1 
 b/kernel/rcu/refscale.c                                  |    9 
 b/kernel/rcu/srcutiny.c                                  |   13 
 b/kernel/rcu/srcutree.c                                  |   58 +
 b/kernel/rcu/tasks.h                                     |  617 ---------------
 b/kernel/rcu/tree.c                                      |    2 
 b/kernel/rcu/update.c                                    |    8 
 b/kernel/tracepoint.c                                    |   21 
 b/scripts/checkpatch.pl                                  |    2 
 b/tools/testing/selftests/rcutorture/configs/rcu/TRACE01 |    1 
 b/tools/testing/selftests/rcutorture/configs/rcu/TRACE02 |    1 
 include/linux/rcupdate.h                                 |    5 
 include/linux/rcupdate_trace.h                           |   85 +-
 include/linux/sched.h                                    |    5 
 include/linux/srcu.h                                     |   40 
 include/linux/srcutiny.h                                 |   16 
 include/linux/srcutree.h                                 |   48 -
 init/init_task.c                                         |    2 
 kernel/fork.c                                            |    2 
 kernel/rcu/Kconfig                                       |   41 
 kernel/rcu/rcu.h                                         |    4 
 kernel/rcu/rcuscale.c                                    |    1 
 kernel/rcu/rcutorture.c                                  |   33 
 kernel/rcu/srcutree.c                                    |   39 
 kernel/rcu/tasks.h                                       |  129 ---
 47 files changed, 529 insertions(+), 990 deletions(-)