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locking/qspinlock: simplify code generation

From:  Nicholas Piggin <npiggin-AT-gmail.com>
To:  Peter Zijlstra <peterz-AT-infradead.org>
Subject:  [PATCH 00/13] locking/qspinlock: simplify code generation
Date:  Tue, 05 Jul 2022 00:38:07 +1000
Message-ID:  <20220704143820.3071004-1-npiggin@gmail.com>
Cc:  Nicholas Piggin <npiggin-AT-gmail.com>, Ingo Molnar <mingo-AT-redhat.com>, Will Deacon <will-AT-kernel.org>, Waiman Long <longman-AT-redhat.com>, Boqun Feng <boqun.feng-AT-gmail.com>, linux-kernel-AT-vger.kernel.org
Archive-link:  Article

Hi,

Been recently looking a bit closer at queued spinlock code, and
found it's a little tricky to follow especially the pv generation.
This series tries to improve the situation. It's not well tested
outside powerpc, but it's really the x86 pv code that is the
other major complexity that should need some review and testing.
Opinions?

Thanks,
Nick

Nicholas Piggin (13):
  locking/qspinlock: remove pv_node abstraction
  locking/qspinlock: inline mcs_spinlock functions into qspinlock
  locking/qspinlock: split common mcs queueing code into its own
    function
  locking/qspinlock: move pv lock word helpers into qspinlock.c
  locking/qspinlock: be less clever with the preprocessor
  locking/qspinlock: merge qspinlock_paravirt.h into qspinlock.c
  locking/qspinlock: remove arch qspinlock_paravirt.h includes
  locking/qspinlock: stop renaming queued_spin_lock_slowpath to
    native_queued_spin_lock_slowpath
  locking/qspinlock: rename __pv_init_lock_hash to pv_spinlocks_init
  locking/qspinlock: paravirt use simple trylock in case idx overflows
  locking/qspinlock: Use queued_spin_trylock in
    pv_hybrid_queued_unfair_trylock
  locking/qspinlock: separate pv_wait_node from the non-paravirt path
  locking/qspinlock: simplify pv_wait_head_or_lock calling scheme

 arch/alpha/include/asm/Kbuild                 |   1 -
 arch/arc/include/asm/Kbuild                   |   1 -
 arch/arm/include/asm/mcs_spinlock.h           |  24 -
 arch/arm64/include/asm/Kbuild                 |   1 -
 arch/hexagon/include/asm/Kbuild               |   1 -
 arch/ia64/include/asm/Kbuild                  |   1 -
 arch/m68k/include/asm/Kbuild                  |   1 -
 arch/microblaze/include/asm/Kbuild            |   1 -
 arch/mips/include/asm/Kbuild                  |   1 -
 arch/nios2/include/asm/Kbuild                 |   1 -
 arch/parisc/include/asm/Kbuild                |   1 -
 arch/powerpc/include/asm/Kbuild               |   1 -
 arch/powerpc/include/asm/qspinlock.h          |  45 +-
 arch/powerpc/include/asm/qspinlock_paravirt.h |   7 -
 arch/powerpc/include/asm/spinlock.h           |   2 +-
 arch/s390/include/asm/Kbuild                  |   1 -
 arch/sh/include/asm/Kbuild                    |   1 -
 arch/sparc/include/asm/Kbuild                 |   1 -
 arch/um/include/asm/Kbuild                    |   1 -
 arch/x86/hyperv/hv_spinlock.c                 |   2 +-
 arch/x86/include/asm/Kbuild                   |   1 -
 arch/x86/include/asm/qspinlock.h              |  19 +-
 arch/x86/include/asm/qspinlock_paravirt.h     |  72 --
 arch/x86/kernel/kvm.c                         |   2 +-
 arch/x86/kernel/paravirt-spinlocks.c          |  71 ++
 arch/x86/kernel/paravirt.c                    |   2 +-
 arch/x86/xen/spinlock.c                       |   2 +-
 arch/xtensa/include/asm/Kbuild                |   1 -
 include/asm-generic/mcs_spinlock.h            |  13 -
 include/asm-generic/qspinlock.h               |   6 +
 kernel/locking/mcs_spinlock.h                 | 121 ---
 kernel/locking/qspinlock.c                    | 834 ++++++++++++++----
 kernel/locking/qspinlock_paravirt.h           | 562 ------------
 33 files changed, 764 insertions(+), 1037 deletions(-)
 delete mode 100644 arch/arm/include/asm/mcs_spinlock.h
 delete mode 100644 arch/powerpc/include/asm/qspinlock_paravirt.h
 delete mode 100644 arch/x86/include/asm/qspinlock_paravirt.h
 delete mode 100644 include/asm-generic/mcs_spinlock.h
 delete mode 100644 kernel/locking/mcs_spinlock.h
 delete mode 100644 kernel/locking/qspinlock_paravirt.h

-- 
2.35.1



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