[PATCH V2 00/11] rcu/x86: Use per-cpu rcu preempt count

[Lai Jiangshan]

From: Lai Jiangshan <jiangshan.ljs@xxxxxxxxxxxx>


Changed from v1:
	Merge thunk_64.S and thunk_32.S into thunk.S
	Add missing #ifdef in arch/x86/kernel/cpu/common.c

X86 can access percpu data in a single instruction.

Use per-cpu rcu preempt count and make it able to be inlined.

patch 1-8: prepare
patch 9-11: implement PCPU_RCU_PREEMPT_COUNT

Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Frederic Weisbecker <frederic@xxxxxxxxxx>


Lai Jiangshan (11):
  lib: Use rcu_preempt_depth() to replace current->rcu_read_lock_nesting
  rcu: Move rcu_preempt_depth_set() to rcupdate.h
  rcu: Reorder tree_exp.h after tree_plugin.h
  rcu: Add macros set_rcu_preempt_special() and
    clear_rcu_preempt_special()
  rcu: Make rcu_read_unlock_special() global
  rcu: Rename marco __LINUX_RCU_H to __KERNEL_RCU_H
  sched/core: Add rcu_preempt_switch()
  x86/entry: Merge thunk_64.S and thunk_32.S into thunk.S
  rcu: Implement PCPU_RCU_PREEMPT_COUNT framework
  x86/rcu: Add rcu_preempt_count
  x86/rcu: Add THUNK rcu_read_unlock_special_thunk

 arch/x86/Kconfig                       |   1 +
 arch/x86/entry/Makefile                |   2 +-
 arch/x86/entry/{thunk_64.S => thunk.S} |   5 ++
 arch/x86/entry/thunk_32.S              |  18 ----
 arch/x86/include/asm/current.h         |   3 +
 arch/x86/include/asm/rcu_preempt.h     | 109 +++++++++++++++++++++++++
 arch/x86/kernel/cpu/common.c           |   4 +
 include/linux/rcupdate.h               |  36 ++++++++
 kernel/rcu/Kconfig                     |   8 ++
 kernel/rcu/rcu.h                       |  15 +++-
 kernel/rcu/tree.c                      |   2 +-
 kernel/rcu/tree_exp.h                  |   2 +-
 kernel/rcu/tree_plugin.h               |  41 ++++++----
 kernel/sched/core.c                    |   2 +
 lib/locking-selftest.c                 |   6 +-
 15 files changed, 212 insertions(+), 42 deletions(-)
 rename arch/x86/entry/{thunk_64.S => thunk.S} (72%)
 delete mode 100644 arch/x86/entry/thunk_32.S
 create mode 100644 arch/x86/include/asm/rcu_preempt.h


base-commit: f2f80ac809875855ac843f9e5e7480604b5cbff5
-- 
2.19.1.6.gb485710b