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authorLinus Torvalds <torvalds@linux-foundation.org>2023-05-05 22:56:55 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2023-05-05 22:56:55 +0300
commitb115d85a9584c98f9a7dec209d835462aa1adc09 (patch)
tree332af6e2fafef47b9dc9891282b422eb5dcc5f3f /include
parentd5ed10bb80bb376501cb56015a47457647efaabf (diff)
parentec570320b09f76d52819e60abdccf372658216b6 (diff)
downloadlinux-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 'include')
-rw-r--r--include/asm-generic/local.h1
-rw-r--r--include/asm-generic/local64.h12
-rw-r--r--include/linux/atomic/atomic-arch-fallback.h24
-rw-r--r--include/linux/atomic/atomic-instrumented.h86
4 files changed, 87 insertions, 36 deletions
diff --git a/include/asm-generic/local.h b/include/asm-generic/local.h
index fca7f1d84818..7f97018df66f 100644
--- a/include/asm-generic/local.h
+++ b/include/asm-generic/local.h
@@ -42,6 +42,7 @@ typedef struct
#define local_inc_return(l) atomic_long_inc_return(&(l)->a)
#define local_cmpxchg(l, o, n) atomic_long_cmpxchg((&(l)->a), (o), (n))
+#define local_try_cmpxchg(l, po, n) atomic_long_try_cmpxchg((&(l)->a), (po), (n))
#define local_xchg(l, n) atomic_long_xchg((&(l)->a), (n))
#define local_add_unless(l, _a, u) atomic_long_add_unless((&(l)->a), (_a), (u))
#define local_inc_not_zero(l) atomic_long_inc_not_zero(&(l)->a)
diff --git a/include/asm-generic/local64.h b/include/asm-generic/local64.h
index 765be0b7d883..14963a7a6253 100644
--- a/include/asm-generic/local64.h
+++ b/include/asm-generic/local64.h
@@ -42,7 +42,16 @@ typedef struct {
#define local64_sub_return(i, l) local_sub_return((i), (&(l)->a))
#define local64_inc_return(l) local_inc_return(&(l)->a)
-#define local64_cmpxchg(l, o, n) local_cmpxchg((&(l)->a), (o), (n))
+static inline s64 local64_cmpxchg(local64_t *l, s64 old, s64 new)
+{
+ return local_cmpxchg(&l->a, old, new);
+}
+
+static inline bool local64_try_cmpxchg(local64_t *l, s64 *old, s64 new)
+{
+ return local_try_cmpxchg(&l->a, (long *)old, new);
+}
+
#define local64_xchg(l, n) local_xchg((&(l)->a), (n))
#define local64_add_unless(l, _a, u) local_add_unless((&(l)->a), (_a), (u))
#define local64_inc_not_zero(l) local_inc_not_zero(&(l)->a)
@@ -81,6 +90,7 @@ typedef struct {
#define local64_inc_return(l) atomic64_inc_return(&(l)->a)
#define local64_cmpxchg(l, o, n) atomic64_cmpxchg((&(l)->a), (o), (n))
+#define local64_try_cmpxchg(l, po, n) atomic64_try_cmpxchg((&(l)->a), (po), (n))
#define local64_xchg(l, n) atomic64_xchg((&(l)->a), (n))
#define local64_add_unless(l, _a, u) atomic64_add_unless((&(l)->a), (_a), (u))
#define local64_inc_not_zero(l) atomic64_inc_not_zero(&(l)->a)
diff --git a/include/linux/atomic/atomic-arch-fallback.h b/include/linux/atomic/atomic-arch-fallback.h
index 4226379a232d..a6e4437c5f36 100644
--- a/include/linux/atomic/atomic-arch-fallback.h
+++ b/include/linux/atomic/atomic-arch-fallback.h
@@ -217,6 +217,28 @@
#endif /* arch_try_cmpxchg64_relaxed */
+#ifndef arch_try_cmpxchg_local
+#define arch_try_cmpxchg_local(_ptr, _oldp, _new) \
+({ \
+ typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+ ___r = arch_cmpxchg_local((_ptr), ___o, (_new)); \
+ if (unlikely(___r != ___o)) \
+ *___op = ___r; \
+ likely(___r == ___o); \
+})
+#endif /* arch_try_cmpxchg_local */
+
+#ifndef arch_try_cmpxchg64_local
+#define arch_try_cmpxchg64_local(_ptr, _oldp, _new) \
+({ \
+ typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+ ___r = arch_cmpxchg64_local((_ptr), ___o, (_new)); \
+ if (unlikely(___r != ___o)) \
+ *___op = ___r; \
+ likely(___r == ___o); \
+})
+#endif /* arch_try_cmpxchg64_local */
+
#ifndef arch_atomic_read_acquire
static __always_inline int
arch_atomic_read_acquire(const atomic_t *v)
@@ -2646,4 +2668,4 @@ arch_atomic64_dec_if_positive(atomic64_t *v)
#endif
#endif /* _LINUX_ATOMIC_FALLBACK_H */
-// 00071fffa021cec66f6290d706d69c91df87bade
+// ad2e2b4d168dbc60a73922616047a9bfa446af36
diff --git a/include/linux/atomic/atomic-instrumented.h b/include/linux/atomic/atomic-instrumented.h
index 0496816738ca..03a232a1fa57 100644
--- a/include/linux/atomic/atomic-instrumented.h
+++ b/include/linux/atomic/atomic-instrumented.h
@@ -1948,14 +1948,14 @@ atomic_long_dec_if_positive(atomic_long_t *v)
({ \
typeof(ptr) __ai_ptr = (ptr); \
kcsan_mb(); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
arch_xchg(__ai_ptr, __VA_ARGS__); \
})
#define xchg_acquire(ptr, ...) \
({ \
typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
arch_xchg_acquire(__ai_ptr, __VA_ARGS__); \
})
@@ -1963,14 +1963,14 @@ atomic_long_dec_if_positive(atomic_long_t *v)
({ \
typeof(ptr) __ai_ptr = (ptr); \
kcsan_release(); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
arch_xchg_release(__ai_ptr, __VA_ARGS__); \
})
#define xchg_relaxed(ptr, ...) \
({ \
typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
arch_xchg_relaxed(__ai_ptr, __VA_ARGS__); \
})
@@ -1978,14 +1978,14 @@ atomic_long_dec_if_positive(atomic_long_t *v)
({ \
typeof(ptr) __ai_ptr = (ptr); \
kcsan_mb(); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
arch_cmpxchg(__ai_ptr, __VA_ARGS__); \
})
#define cmpxchg_acquire(ptr, ...) \
({ \
typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
arch_cmpxchg_acquire(__ai_ptr, __VA_ARGS__); \
})
@@ -1993,14 +1993,14 @@ atomic_long_dec_if_positive(atomic_long_t *v)
({ \
typeof(ptr) __ai_ptr = (ptr); \
kcsan_release(); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
arch_cmpxchg_release(__ai_ptr, __VA_ARGS__); \
})
#define cmpxchg_relaxed(ptr, ...) \
({ \
typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
arch_cmpxchg_relaxed(__ai_ptr, __VA_ARGS__); \
})
@@ -2008,14 +2008,14 @@ atomic_long_dec_if_positive(atomic_long_t *v)
({ \
typeof(ptr) __ai_ptr = (ptr); \
kcsan_mb(); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
arch_cmpxchg64(__ai_ptr, __VA_ARGS__); \
})
#define cmpxchg64_acquire(ptr, ...) \
({ \
typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
arch_cmpxchg64_acquire(__ai_ptr, __VA_ARGS__); \
})
@@ -2023,14 +2023,14 @@ atomic_long_dec_if_positive(atomic_long_t *v)
({ \
typeof(ptr) __ai_ptr = (ptr); \
kcsan_release(); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
arch_cmpxchg64_release(__ai_ptr, __VA_ARGS__); \
})
#define cmpxchg64_relaxed(ptr, ...) \
({ \
typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
arch_cmpxchg64_relaxed(__ai_ptr, __VA_ARGS__); \
})
@@ -2039,8 +2039,8 @@ atomic_long_dec_if_positive(atomic_long_t *v)
typeof(ptr) __ai_ptr = (ptr); \
typeof(oldp) __ai_oldp = (oldp); \
kcsan_mb(); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_read_write(__ai_oldp, sizeof(*__ai_oldp)); \
arch_try_cmpxchg(__ai_ptr, __ai_oldp, __VA_ARGS__); \
})
@@ -2048,8 +2048,8 @@ atomic_long_dec_if_positive(atomic_long_t *v)
({ \
typeof(ptr) __ai_ptr = (ptr); \
typeof(oldp) __ai_oldp = (oldp); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_read_write(__ai_oldp, sizeof(*__ai_oldp)); \
arch_try_cmpxchg_acquire(__ai_ptr, __ai_oldp, __VA_ARGS__); \
})
@@ -2058,8 +2058,8 @@ atomic_long_dec_if_positive(atomic_long_t *v)
typeof(ptr) __ai_ptr = (ptr); \
typeof(oldp) __ai_oldp = (oldp); \
kcsan_release(); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_read_write(__ai_oldp, sizeof(*__ai_oldp)); \
arch_try_cmpxchg_release(__ai_ptr, __ai_oldp, __VA_ARGS__); \
})
@@ -2067,8 +2067,8 @@ atomic_long_dec_if_positive(atomic_long_t *v)
({ \
typeof(ptr) __ai_ptr = (ptr); \
typeof(oldp) __ai_oldp = (oldp); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_read_write(__ai_oldp, sizeof(*__ai_oldp)); \
arch_try_cmpxchg_relaxed(__ai_ptr, __ai_oldp, __VA_ARGS__); \
})
@@ -2077,8 +2077,8 @@ atomic_long_dec_if_positive(atomic_long_t *v)
typeof(ptr) __ai_ptr = (ptr); \
typeof(oldp) __ai_oldp = (oldp); \
kcsan_mb(); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_read_write(__ai_oldp, sizeof(*__ai_oldp)); \
arch_try_cmpxchg64(__ai_ptr, __ai_oldp, __VA_ARGS__); \
})
@@ -2086,8 +2086,8 @@ atomic_long_dec_if_positive(atomic_long_t *v)
({ \
typeof(ptr) __ai_ptr = (ptr); \
typeof(oldp) __ai_oldp = (oldp); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_read_write(__ai_oldp, sizeof(*__ai_oldp)); \
arch_try_cmpxchg64_acquire(__ai_ptr, __ai_oldp, __VA_ARGS__); \
})
@@ -2096,8 +2096,8 @@ atomic_long_dec_if_positive(atomic_long_t *v)
typeof(ptr) __ai_ptr = (ptr); \
typeof(oldp) __ai_oldp = (oldp); \
kcsan_release(); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_read_write(__ai_oldp, sizeof(*__ai_oldp)); \
arch_try_cmpxchg64_release(__ai_ptr, __ai_oldp, __VA_ARGS__); \
})
@@ -2105,22 +2105,22 @@ atomic_long_dec_if_positive(atomic_long_t *v)
({ \
typeof(ptr) __ai_ptr = (ptr); \
typeof(oldp) __ai_oldp = (oldp); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_read_write(__ai_oldp, sizeof(*__ai_oldp)); \
arch_try_cmpxchg64_relaxed(__ai_ptr, __ai_oldp, __VA_ARGS__); \
})
#define cmpxchg_local(ptr, ...) \
({ \
typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
arch_cmpxchg_local(__ai_ptr, __VA_ARGS__); \
})
#define cmpxchg64_local(ptr, ...) \
({ \
typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
arch_cmpxchg64_local(__ai_ptr, __VA_ARGS__); \
})
@@ -2128,15 +2128,33 @@ atomic_long_dec_if_positive(atomic_long_t *v)
({ \
typeof(ptr) __ai_ptr = (ptr); \
kcsan_mb(); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
arch_sync_cmpxchg(__ai_ptr, __VA_ARGS__); \
})
+#define try_cmpxchg_local(ptr, oldp, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ typeof(oldp) __ai_oldp = (oldp); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_read_write(__ai_oldp, sizeof(*__ai_oldp)); \
+ arch_try_cmpxchg_local(__ai_ptr, __ai_oldp, __VA_ARGS__); \
+})
+
+#define try_cmpxchg64_local(ptr, oldp, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ typeof(oldp) __ai_oldp = (oldp); \
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_read_write(__ai_oldp, sizeof(*__ai_oldp)); \
+ arch_try_cmpxchg64_local(__ai_ptr, __ai_oldp, __VA_ARGS__); \
+})
+
#define cmpxchg_double(ptr, ...) \
({ \
typeof(ptr) __ai_ptr = (ptr); \
kcsan_mb(); \
- instrument_atomic_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \
+ instrument_atomic_read_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \
arch_cmpxchg_double(__ai_ptr, __VA_ARGS__); \
})
@@ -2144,9 +2162,9 @@ atomic_long_dec_if_positive(atomic_long_t *v)
#define cmpxchg_double_local(ptr, ...) \
({ \
typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \
+ instrument_atomic_read_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \
arch_cmpxchg_double_local(__ai_ptr, __VA_ARGS__); \
})
#endif /* _LINUX_ATOMIC_INSTRUMENTED_H */
-// 1b485de9cbaa4900de59e14ee2084357eaeb1c3a
+// 6b513a42e1a1b5962532a019b7fc91eaa044ad5e