Messages in this thread | | | From | guoren@kernel ... | Subject | [PATCH V4 0/3] csky: Optimize atomic_ops & cmpxchg | Date | Sun, 24 Apr 2022 15:29:15 +0800 |
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From: Guo Ren <guoren@linux.alibaba.com>
Optimize arch_xchg|cmpxchg|cmpxchg_local with ASM acquire|release instructions instead of previous C based.
The generic atomic.h used cmpxchg to implement the atomic operations, it will cause daul loop to reduce the forward guarantee. The patch implement csky custom atomic operations with ldex/stex instructions for the best performance.
Changes in V4: - Remove RELEASE_FENCE in ldex/stex loop by Buoqun's advice
Changes in V3: - Add arch_atomic_(fetch_add_unless, inc_unless_negative, dec_unless_positive, dec_if_positive)
Changes in V2: - Fixup use of acquire + release for barrier semantics by Rutland.
Guo Ren (3): csky: atomic: Optimize cmpxchg with acquire & release csky: atomic: Add custom atomic.h implementation csky: atomic: Add conditional atomic operations' optimization
arch/csky/include/asm/atomic.h | 237 ++++++++++++++++++++++++++++++++ arch/csky/include/asm/barrier.h | 11 +- arch/csky/include/asm/cmpxchg.h | 64 ++++++++- 3 files changed, 304 insertions(+), 8 deletions(-) create mode 100644 arch/csky/include/asm/atomic.h
-- 2.25.1
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