Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull RCU updates from Ingo Molnar:
 "The biggest change in this cycle is the conclusion of the big
  'simplify RCU to two primary flavors' consolidation work - i.e.
  there's a single RCU flavor for any kernel variant (PREEMPT and
  !PREEMPT):

    - 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.

    - 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.

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

    - 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.

  There were also other updates:

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

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

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

    - 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"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (140 commits)
  srcu: Make early-boot call_srcu() reuse workqueue lists
  rcutorture: Test early boot call_srcu()
  srcu: Make call_srcu() available during very early boot
  rcu: Convert rcu_state.ofl_lock to raw_spinlock_t
  rcu: Remove obsolete ->dynticks_fqs and ->cond_resched_completed
  rcu: Switch ->dynticks to rcu_data structure, remove rcu_dynticks
  rcu: Switch dyntick nesting counters to rcu_data structure
  rcu: Switch urgent quiescent-state requests to rcu_data structure
  rcu: Switch lazy counts to rcu_data structure
  rcu: Switch last accelerate/advance to rcu_data structure
  rcu: Switch ->tick_nohz_enabled_snap to rcu_data structure
  rcu: Merge rcu_dynticks structure into rcu_data structure
  rcu: Remove unused rcu_dynticks_snap() from Tiny RCU
  rcu: Convert "1UL << x" to "BIT(x)"
  rcu: Avoid resched_cpu() when rescheduling the current CPU
  rcu: More aggressively enlist scheduler aid for nohz_full CPUs
  rcu: Compute jiffies_till_sched_qs from other kernel parameters
  rcu: Provide functions for determining if call_rcu() has been invoked
  rcu: Eliminate ->rcu_qs_ctr from the rcu_dynticks structure
  rcu: Motivate Tiny RCU forward progress
  ...
This commit is contained in:
Linus Torvalds 2018-10-23 12:31:17 +01:00
commit cee1352f79
40 changed files with 2294 additions and 2752 deletions

View file

@ -393,9 +393,8 @@ TRACE_EVENT(rcu_quiescent_state_report,
* Tracepoint for quiescent states detected by force_quiescent_state().
* These trace events include the type of RCU, the grace-period number
* that was blocked by the CPU, the CPU itself, and the type of quiescent
* state, which can be "dti" for dyntick-idle mode, "kick" when kicking
* a CPU that has been in dyntick-idle mode for too long, or "rqc" if the
* CPU got a quiescent state via its rcu_qs_ctr.
* state, which can be "dti" for dyntick-idle mode or "kick" when kicking
* a CPU that has been in dyntick-idle mode for too long.
*/
TRACE_EVENT(rcu_fqs,
@ -705,20 +704,20 @@ TRACE_EVENT(rcu_torture_read,
);
/*
* Tracepoint for _rcu_barrier() execution. The string "s" describes
* the _rcu_barrier phase:
* "Begin": _rcu_barrier() started.
* "EarlyExit": _rcu_barrier() piggybacked, thus early exit.
* "Inc1": _rcu_barrier() piggyback check counter incremented.
* "OfflineNoCB": _rcu_barrier() found callback on never-online CPU
* "OnlineNoCB": _rcu_barrier() found online no-CBs CPU.
* "OnlineQ": _rcu_barrier() found online CPU with callbacks.
* "OnlineNQ": _rcu_barrier() found online CPU, no callbacks.
* Tracepoint for rcu_barrier() execution. The string "s" describes
* the rcu_barrier phase:
* "Begin": rcu_barrier() started.
* "EarlyExit": rcu_barrier() piggybacked, thus early exit.
* "Inc1": rcu_barrier() piggyback check counter incremented.
* "OfflineNoCB": rcu_barrier() found callback on never-online CPU
* "OnlineNoCB": rcu_barrier() found online no-CBs CPU.
* "OnlineQ": rcu_barrier() found online CPU with callbacks.
* "OnlineNQ": rcu_barrier() found online CPU, no callbacks.
* "IRQ": An rcu_barrier_callback() callback posted on remote CPU.
* "IRQNQ": An rcu_barrier_callback() callback found no callbacks.
* "CB": An rcu_barrier_callback() invoked a callback, not the last.
* "LastCB": An rcu_barrier_callback() invoked the last callback.
* "Inc2": _rcu_barrier() piggyback check counter incremented.
* "Inc2": rcu_barrier() piggyback check counter incremented.
* The "cpu" argument is the CPU or -1 if meaningless, the "cnt" argument
* is the count of remaining callbacks, and "done" is the piggybacking count.
*/