[GIT PULL rcu/next] RCU commits for 4.20/5.0

From: Paul E. McKenney
Date: Wed Sep 26 2018 - 14:22:13 EST


Hello, Ingo,

This pull request contains the following changes:

1. Documentation updates, including some good-eye catches from
Joel Fernandes.

http://lkml.kernel.org/r/20180829211637.GA20980@xxxxxxxxxxxxxxxxxx

2. SRCU updates, most notably changes enabling call_srcu() to be
invoked very early in the boot sequence.

http://lkml.kernel.org/r/20180829212036.GA22033@xxxxxxxxxxxxxxxxxx

3. Torture-test updates, including some preliminary work towards
making rcutorture better able to find problems that result in
insufficient grace-period forward progress.

http://lkml.kernel.org/r/20180829214722.GA23411@xxxxxxxxxxxxxxxxxx

4. Consolidate the RCU-bh, RCU-preempt, and RCU-sched flavors into
a single flavor similar to RCU-sched in !PREEMPT kernels and
into a single flavor similar to RCU-preempt (but also waiting
on preempt-disabled sequences of code) in PREEMPT kernels. This
branch also includes a refactoring of rcu_{nmi,irq}_{enter,exit}()
from Byungchul Park.

http://lkml.kernel.org/r/20180829222021.GA29944@xxxxxxxxxxxxxxxxxx

5. Now that there is only one RCU flavor in any given running kernel,
the many "rsp" pointers are no longer required, and this cleanup
series removes them.

http://lkml.kernel.org/r/20180829223830.GA1800@xxxxxxxxxxxxxxxxxx

6. This branch carries out additional cleanups made possible by
the RCU flavor consolidation, including inlining how-trivial
functions, updating comments and definitions, and removing
now-unneeded rcutorture scenarios.

http://lkml.kernel.org/r/20180829225340.GA7019@xxxxxxxxxxxxxxxxxx

7. Initial changes to RCU to better promote forward progress of
grace periods, including fixing a bug found by Marius Hillenbrand
and David Woodhouse, with the fix suggested by Peter Zijlstra.

http://lkml.kernel.org/r/20180829230035.GA7751@xxxxxxxxxxxxxxxxxx

8. Now that there is only one flavor of RCU in any running kernel,
there is also only on rcu_data structure per CPU. This means
that the rcu_dynticks structure can be merged into the rcu_data
structure, a task taken on by this branch. This branch also
contains a -rt-related fix from Mike Galbraith.

http://lkml.kernel.org/r/20180829230715.GA9431@xxxxxxxxxxxxxxxxxx

Once again, the layout of this pull request is unusual due to the large
footprint of the commits in #4-#8 above. These five branches are therefore
stacked on top of each other instead of my usual practice of laying them
out in parallel.

This pull request decreases the size of RCU by more than 450 lines,
offsetting the increase of the v4.19 merge window. I expect a further
decrease due to additional outside-of-RCU cleanups, though this will be
offset by additional forward-progress testing and fixes in response to
Marius's and David's location of a forward-progress bug that escaped to
the field -- rcutorture should have located that bug, after all.

All of these changes have been subjected to 0day Test Robot and -next
testing, and are available in the git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git for-mingo

for you to fetch changes up to b56ada120921fbb0a4fb2a5bee163717182e7e9e:

Merge branches 'doc.2018.08.30a', 'dynticks.2018.08.30b', 'srcu.2018.08.30b' and 'torture.2018.08.29a' into HEAD (2018-08-30 16:12:53 -0700)

----------------------------------------------------------------
Byungchul Park (1):
rcu: Refactor rcu_{nmi,irq}_{enter,exit}()

Joel Fernandes (Google) (2):
doc: Fix broken RCU-requirements link to LKML archive
doc: Improve rcu_dynticks::dynticks documentation

Mike Galbraith (1):
rcu: Convert rcu_state.ofl_lock to raw_spinlock_t

Paul E. McKenney (137):
doc: Add design documentation on interruption of NMI handlers
torture: Stop overwriting Make.out file with obsolete version
rcutorture: Force occasional reader waits
rcutorture: Warn on bad torture type for built-in tests
rcuperf: Warn on bad perf type for built-in tests
rcutorture: Remove TREE06 and TREE08 from the default test list
rcutorture: Add forward-progress tests for RCU grace periods
rcutorture: Also use GP sequence to judge forward progress
rcutorture: Avoid no-test complaint if too few forward-progress tries
rcutorture: Vary forward-progress test interval
rcutorture: Add self-propagating callback to forward-progress testing
rcutorture: Increase rcu_read_delay() longdelay_ms
rcutorture: Limit reader duration if irq or bh disabled
rcutorture: Reduce priority of forward-progress testing
rcutorture: Adjust number of reader kthreads per CPU-hotplug operations
rcutorture: Print forward-progress test interval on error
rcutorture: Check GP completion at stutter end
rcutorture: Maintain self-propagating CB only during forward-progress test
doc: Update removal of RCU-bh/sched update machinery
doc: Fix broken HTML directive
rcu: Defer reporting RCU-preempt quiescent states when disabled
rcutorture: Test extended "rcu" read-side critical sections
rcu: Allow processing deferred QSes for exiting RCU-preempt readers
rcu: Remove now-unused ->b.exp_need_qs field from the rcu_special union
rcu: Add warning to detect half-interrupts
rcu: Apply RCU-bh QSes to RCU-sched and RCU-preempt when safe
rcu: Report expedited grace periods at context-switch time
rcu: Define RCU-bh update API in terms of RCU
rcu: Update comments and help text for no more RCU-bh updaters
rcu: Drop "wake" parameter from rcu_report_exp_rdp()
rcu: Fix typo in rcu_get_gp_kthreads_prio() header comment
rcu: Define RCU-sched API in terms of RCU for Tree RCU PREEMPT builds
rcu: Express Tiny RCU updates in terms of RCU rather than RCU-sched
rcu: Remove RCU_STATE_INITIALIZER()
rcu: Eliminate rcu_state structure's ->call field
rcu: Remove rcu_state structure's ->rda field
rcu: Remove rcu_state_p pointer to default rcu_state structure
rcu: Remove rcu_data_p pointer to default rcu_data structure
rcu: Remove rsp parameter from rcu_report_qs_rnp()
rcu: Remove rsp parameter from rcu_report_qs_rsp()
rcu: Remove rsp parameter from rcu_report_unblock_qs_rnp()
rcu: Remove rsp parameter from rcu_report_qs_rdp()
rcu: Remove rsp parameter from rcu_gp_in_progress()
rcu: Remove rsp parameter from rcu_get_root()
rcu: Remove rsp parameter from record_gp_stall_check_time()
rcu: Remove rsp parameter from rcu_check_gp_kthread_starvation()
rcu: Remove rsp parameter from rcu_dump_cpu_stacks()
rcu: Remove rsp parameter from rcu_stall_kick_kthreads()
rcu: Remove rsp parameter from print_other_cpu_stall()
rcu: Remove rsp parameter from print_cpu_stall()
rcu: Remove rsp parameter from check_cpu_stall()
rcu: Remove rsp parameter from rcu_future_gp_cleanup()
rcu: Remove rsp parameter from rcu_gp_kthread_wake()
rcu: Remove rsp parameter from rcu_accelerate_cbs()
rcu: Remove rsp parameter from rcu_accelerate_cbs_unlocked()
rcu: Remove rsp parameter from rcu_advance_cbs()
rcu: Remove rsp parameter from __note_gp_changes()
rcu: Remove rsp parameter from note_gp_changes()
rcu: Remove rsp parameter from rcu_gp_slow()
rcu: Remove rsp parameter from rcu_gp_kthread() and friends
rcu: Remove rsp parameter from rcu_check_quiescent_state()
rcu: Remove rsp parameter from CPU hotplug functions
rcu: Remove rsp parameter from rcu_do_batch()
rcu: Remove rsp parameter from force-quiescent-state functions
rcu: Remove rsp parameter from rcu_check_gp_start_stall()
rcu: Remove rsp parameter from __rcu_process_callbacks()
rcu: Remove rsp parameter from __call_rcu() and friend
rcu: Remove rsp parameter from __rcu_pending()
rcu: Remove rsp parameter from _rcu_barrier() and friends
rcu: Remove rsp parameter from rcu_boot_init_percpu_data() and friends
rcu: Remove rsp parameter from rcu_init_one() and friends
rcu: Remove rsp parameter from rcu_print_detail_task_stall()
rcu: Remove rsp parameter from dump_blkd_tasks() and friend
rcu: Remove rsp parameter from rcu_spawn_one_boost_kthread()
rcu: Remove rsp parameter from print_cpu_stall_info()
rcu: Remove rsp parameter from no-CBs CPU functions
rcu: Remove rsp parameter from expedited grace-period functions
rcu: Remove rsp parameter from rcu_node tree accessor macros
rcu: Remove rcu_data structure's ->rsp field
rcu: Remove last non-flavor-traversal rsp local variable from tree_plugin.h
rcu: Remove for_each_rcu_flavor() flavor-traversal macro
rcu: Simplify rcutorture_get_gp_data()
rcu: Restructure rcu_check_gp_kthread_starvation()
rcu: Eliminate stall-warning use of rsp
rcu: Eliminate grace-period management code use of rsp
rcu: Eliminate callback-invocation/invocation use of rsp
rcu: Eliminate quiescent-state and grace-period-nonstart use of rsp
rcu: Eliminate RCU-barrier use of rsp
rcu: Eliminate initialization-time use of rsp
rcu: Fix typo in force_qs_rnp()'s parameter's parameter
rcu: Inline increment_cpu_stall_ticks() into its sole caller
rcu: Pull rcu_gp_kthread() FQS loop into separate function
rcu: Consolidate RCU-bh update-side function definitions
rcu: Consolidate RCU-sched update-side function definitions
rcutorture: Add RCU-bh and RCU-sched support for extended readers
rcu: Stop testing RCU-bh and RCU-sched
rcutorture: Remove the "rcu_bh" and "sched" torture types
rcuperf: Remove the "rcu_bh" and "sched" torture types
rcu: Remove now-unused rcutorture APIs
rcu: Clean up flavor-related definitions and comments in rcupdate.h
rcu: Clean up flavor-related definitions and comments in rculist.h
rcu: Clean up flavor-related definitions and comments in rcupdate_wait.h
rcu: Clean up flavor-related definitions and comments in Kconfig
rcu: Clean up flavor-related definitions and comments in rcu.h
rcu: Clean up flavor-related definitions and comments in rcutorture.c
rcu: Clean up flavor-related definitions and comments in srcutree.h
rcu: Clean up flavor-related definitions and comments in tiny.c
rcu: Clean up flavor-related definitions and comments in tree.c
rcu: Clean up flavor-related definitions and comments in tree_exp.h
rcu: Clean up flavor-related definitions and comments in tree_plugin.h
rcu: Clean up flavor-related definitions and comments in update.c
rcu: Remove !PREEMPT code from rcu_note_voluntary_context_switch()
rcu: Define rcu_all_qs() only in !PREEMPT builds
rcu: Inline _rcu_barrier() into its sole remaining caller
rcu: Make need_resched() respond to urgent RCU-QS needs
rcu: Provide improved interrupt-from-idle check in rcu_check_callbacks()
rcutorture: Dump reader protection sequence if failures or close calls
rcu: Motivate Tiny RCU forward progress
rcu: Eliminate ->rcu_qs_ctr from the rcu_dynticks structure
rcu: Provide functions for determining if call_rcu() has been invoked
rcu: Compute jiffies_till_sched_qs from other kernel parameters
rcu: More aggressively enlist scheduler aid for nohz_full CPUs
rcu: Avoid resched_cpu() when rescheduling the current CPU
rcu: Convert "1UL << x" to "BIT(x)"
rcu: Remove unused rcu_dynticks_snap() from Tiny RCU
rcu: Merge rcu_dynticks structure into rcu_data structure
rcu: Switch ->tick_nohz_enabled_snap to rcu_data structure
rcu: Switch last accelerate/advance to rcu_data structure
rcu: Switch lazy counts to rcu_data structure
rcu: Switch urgent quiescent-state requests to rcu_data structure
rcu: Switch dyntick nesting counters to rcu_data structure
rcu: Switch ->dynticks to rcu_data structure, remove rcu_dynticks
rcu: Remove obsolete ->dynticks_fqs and ->cond_resched_completed
srcu: Make call_srcu() available during very early boot
rcutorture: Test early boot call_srcu()
srcu: Make early-boot call_srcu() reuse workqueue lists
Merge branches 'doc.2018.08.30a', 'dynticks.2018.08.30b', 'srcu.2018.08.30b' and 'torture.2018.08.29a' into HEAD

.../Design/Data-Structures/Data-Structures.html | 31 +-
.../Expedited-Grace-Periods.html | 9 +-
.../RCU/Design/Requirements/Requirements.html | 214 +-
Documentation/RCU/stallwarn.txt | 13 +-
Documentation/RCU/whatisRCU.txt | 3 +-
Documentation/admin-guide/kernel-parameters.txt | 31 +-
Documentation/kernel-per-CPU-kthreads.txt | 2 +-
include/linux/rculist.h | 32 +-
include/linux/rcupdate.h | 154 +-
include/linux/rcupdate_wait.h | 14 +-
include/linux/rcutiny.h | 53 +-
include/linux/rcutree.h | 31 +-
include/linux/sched.h | 6 +-
include/linux/srcutree.h | 13 +-
include/linux/torture.h | 2 +-
include/trace/events/rcu.h | 25 +-
kernel/rcu/Kconfig | 14 +-
kernel/rcu/rcu.h | 67 +-
kernel/rcu/rcuperf.c | 66 +-
kernel/rcu/rcutorture.c | 397 ++--
kernel/rcu/srcutiny.c | 29 +-
kernel/rcu/srcutree.c | 31 +-
kernel/rcu/tiny.c | 154 +-
kernel/rcu/tree.c | 2213 ++++++++------------
kernel/rcu/tree.h | 132 +-
kernel/rcu/tree_exp.h | 426 ++--
kernel/rcu/tree_plugin.h | 790 +++----
kernel/rcu/update.c | 70 +-
kernel/softirq.c | 3 +-
kernel/torture.c | 3 +-
.../selftests/rcutorture/bin/kvm-test-1-run.sh | 1 -
.../selftests/rcutorture/configs/rcu/CFLIST | 2 -
.../selftests/rcutorture/configs/rcu/SRCU-P.boot | 1 +
.../selftests/rcutorture/configs/rcu/SRCU-u.boot | 1 +
.../selftests/rcutorture/configs/rcu/TINY02.boot | 2 -
.../selftests/rcutorture/configs/rcu/TREE01.boot | 2 +-
.../selftests/rcutorture/configs/rcu/TREE04.boot | 2 +-
.../selftests/rcutorture/configs/rcu/TREE05.boot | 3 +-
.../selftests/rcutorture/configs/rcu/TREE06.boot | 2 -
.../selftests/rcutorture/configs/rcu/TREE08.boot | 2 -
40 files changed, 2294 insertions(+), 2752 deletions(-)