[00/10] locking/rwsem: Rwsem rearchitecture part 1
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Waiman Long Feb. 13, 2019, 12:26 a.m. UTC
This is part 1 of a 3-part (0/1/2) series to rearchitect the internal
operation of rwsem. This depends on the part 0 patches sent out previously

https://lore.kernel.org/lkml/1549913486-16799-1-git-send-email-longman@redhat.com

This part lays the foundation for part 2 without making any functional
changes. This part includes the following changes:

 1) Move code around and rename kernel/locking/rwsem.h to
    kernel/locking/rwsem-xadd.h as it will be specific to rwsem-xadd.c
    (patches 1-4).
 2) Enhance the DEBUG_RWSEMS_WARN_ON() macro to provide more information
    and add additional checks (patches 5 & 6).
 3) Make the core qspinlock_stat.h code generic (lock event counting)
    so that it can be used by all the architectures as well as other
    locking subsystems such as rwsem (patches 7-10). Lock event
    counting help us visualize how frequently a code path is being
    used as well as spotting abnormal behavior due to bugs in the code
    without noticeably affecting kernel performance and hence behavior.

Both (2) and (3) are useful debugging aids.

Waiman Long (10):
  locking/rwsem: Relocate rwsem_down_read_failed()
  locking/rwsem: Move owner setting code from rwsem.c to rwsem.h
  locking/rwsem: Rename kernel/locking/rwsem.h
  locking/rwsem: Move rwsem internal function declarations to
    rwsem-xadd.h
  locking/rwsem: Add debug check for __down_read*()
  locking/rwsem: Enhance DEBUG_RWSEMS_WARN_ON() macro
  locking/qspinlock_stat: Introduce a generic lockevent counting APIs
  locking/lock_events: Make lock_events available for all archs & other
    locks
  locking/lock_events: Don't show pvqspinlock events on bare metal
  locking/rwsem: Enable lock event counting

 arch/Kconfig                        |  10 ++
 arch/x86/Kconfig                    |   8 -
 include/linux/rwsem.h               |   7 -
 kernel/locking/Makefile             |   1 +
 kernel/locking/lock_events.c        | 179 ++++++++++++++++++++++
 kernel/locking/lock_events.h        |  55 +++++++
 kernel/locking/lock_events_list.h   |  67 ++++++++
 kernel/locking/percpu-rwsem.c       |   4 +-
 kernel/locking/qspinlock.c          |   8 +-
 kernel/locking/qspinlock_paravirt.h |  19 +--
 kernel/locking/qspinlock_stat.h     | 242 ++++++-----------------------
 kernel/locking/rwsem-xadd.c         | 192 ++++++++++++-----------
 kernel/locking/rwsem-xadd.h         | 294 ++++++++++++++++++++++++++++++++++++
 kernel/locking/rwsem.c              |  32 ++--
 kernel/locking/rwsem.h              | 264 --------------------------------
 15 files changed, 778 insertions(+), 604 deletions(-)
 create mode 100644 kernel/locking/lock_events.c
 create mode 100644 kernel/locking/lock_events.h
 create mode 100644 kernel/locking/lock_events_list.h
 create mode 100644 kernel/locking/rwsem-xadd.h
 delete mode 100644 kernel/locking/rwsem.h

Comments

Will Deacon Feb. 15, 2019, 6:49 p.m. UTC | #1
On Tue, Feb 12, 2019 at 07:26:57PM -0500, Waiman Long wrote:
> This is part 1 of a 3-part (0/1/2) series to rearchitect the internal
> operation of rwsem. This depends on the part 0 patches sent out previously
> 
> https://lore.kernel.org/lkml/1549913486-16799-1-git-send-email-longman@redhat.com
> 
> This part lays the foundation for part 2 without making any functional
> changes. This part includes the following changes:

Did you post part 2 anywhere? I can't seem to find it for some reason.

Cheers,

Will
Waiman Long Feb. 15, 2019, 6:55 p.m. UTC | #2
On 02/15/2019 01:49 PM, Will Deacon wrote:
> On Tue, Feb 12, 2019 at 07:26:57PM -0500, Waiman Long wrote:
>> This is part 1 of a 3-part (0/1/2) series to rearchitect the internal
>> operation of rwsem. This depends on the part 0 patches sent out previously
>>
>> https://lore.kernel.org/lkml/1549913486-16799-1-git-send-email-longman@redhat.com
>>
>> This part lays the foundation for part 2 without making any functional
>> changes. This part includes the following changes:
> Did you post part 2 anywhere? I can't seem to find it for some reason.
>
> Cheers,
>
> Will

I haven't posted the part 2 yet. I will need to repost part 1 to work
with part 0 v4.

-Longman