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author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-05-05 22:56:55 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-05-05 22:56:55 +0300 |
commit | b115d85a9584c98f9a7dec209d835462aa1adc09 (patch) | |
tree | 332af6e2fafef47b9dc9891282b422eb5dcc5f3f /arch/powerpc | |
parent | d5ed10bb80bb376501cb56015a47457647efaabf (diff) | |
parent | ec570320b09f76d52819e60abdccf372658216b6 (diff) | |
download | linux-b115d85a9584c98f9a7dec209d835462aa1adc09.tar.xz |
Merge tag 'locking-core-2023-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
- Introduce local{,64}_try_cmpxchg() - a slightly more optimal
primitive, which will be used in perf events ring-buffer code
- Simplify/modify rwsems on PREEMPT_RT, to address writer starvation
- Misc cleanups/fixes
* tag 'locking-core-2023-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/atomic: Correct (cmp)xchg() instrumentation
locking/x86: Define arch_try_cmpxchg_local()
locking/arch: Wire up local_try_cmpxchg()
locking/generic: Wire up local{,64}_try_cmpxchg()
locking/atomic: Add generic try_cmpxchg{,64}_local() support
locking/rwbase: Mitigate indefinite writer starvation
locking/arch: Rename all internal __xchg() names to __arch_xchg()
Diffstat (limited to 'arch/powerpc')
-rw-r--r-- | arch/powerpc/include/asm/cmpxchg.h | 4 | ||||
-rw-r--r-- | arch/powerpc/include/asm/local.h | 11 |
2 files changed, 13 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/cmpxchg.h b/arch/powerpc/include/asm/cmpxchg.h index d0ea0571e79a..dbb50c06f0bf 100644 --- a/arch/powerpc/include/asm/cmpxchg.h +++ b/arch/powerpc/include/asm/cmpxchg.h @@ -229,7 +229,7 @@ __xchg_local(void *ptr, unsigned long x, unsigned int size) return __xchg_u64_local(ptr, x); #endif } - BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg"); + BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg_local"); return x; } @@ -248,7 +248,7 @@ __xchg_relaxed(void *ptr, unsigned long x, unsigned int size) return __xchg_u64_relaxed(ptr, x); #endif } - BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg_local"); + BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg_relaxed"); return x; } #define arch_xchg_local(ptr,x) \ diff --git a/arch/powerpc/include/asm/local.h b/arch/powerpc/include/asm/local.h index bc4bd19b7fc2..45492fb5bf22 100644 --- a/arch/powerpc/include/asm/local.h +++ b/arch/powerpc/include/asm/local.h @@ -90,6 +90,17 @@ static __inline__ long local_cmpxchg(local_t *l, long o, long n) return t; } +static __inline__ bool local_try_cmpxchg(local_t *l, long *po, long n) +{ + long o = *po, r; + + r = local_cmpxchg(l, o, n); + if (unlikely(r != o)) + *po = r; + + return likely(r == o); +} + static __inline__ long local_xchg(local_t *l, long n) { long t; |