[PATCH] compiler_types: Introduce inline_for_performance
From: Eric Dumazet <edumazet@google.com>
Date: 2026-01-18 15:24:58
Also in:
lkml
Subsystem:
arm port, generic include/asm header files, the rest · Maintainers:
Russell King, Arnd Bergmann, Linus Torvalds
inline keyword is often ignored by compilers.
We need something slightly stronger in networking fast paths
but __always_inline is too strong.
Instead, generalize idea Nicolas used in commit d533cb2d2af4
("__arch_xprod64(): make __always_inline when optimizing for performance")
This will help CONFIG_CC_OPTIMIZE_FOR_SIZE=y users keeping
their kernels small.
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/netdev/176847720679.3956289.12601442580224129560.git-patchwork-notify@kernel.org/T/#m2d7e201372a8aae1ce62a0b548e55fd4fe804909 (local)
Cc: Nicolas Pitre <redacted>
---
arch/arm/include/asm/div64.h | 6 +-----
include/asm-generic/div64.h | 6 +-----
include/linux/compiler_types.h | 10 ++++++++++
3 files changed, 12 insertions(+), 10 deletions(-)
diff --git a/arch/arm/include/asm/div64.h b/arch/arm/include/asm/div64.h
index d3ef8e416b27d22d38bf084e091b0e4795f74bd4..877dfc4c4c7344849eec2109b66c2825561719dc 100644
--- a/arch/arm/include/asm/div64.h
+++ b/arch/arm/include/asm/div64.h@@ -52,11 +52,7 @@ static inline uint32_t __div64_32(uint64_t *n, uint32_t base) #else -#ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE -static __always_inline -#else -static inline -#endif +static inline_for_performance uint64_t __arch_xprod_64(uint64_t m, uint64_t n, bool bias) { unsigned long long res;
diff --git a/include/asm-generic/div64.h b/include/asm-generic/div64.h
index 25e7b4b58dcf55a395b9db72e01f2cd220da58a0..9893356fff55679304f68833c11c8ae9052b9cea 100644
--- a/include/asm-generic/div64.h
+++ b/include/asm-generic/div64.h@@ -134,11 +134,7 @@ * Hoping for compile-time optimization of conditional code. * Architectures may provide their own optimized assembly implementation. */ -#ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE -static __always_inline -#else -static inline -#endif +static inline_for_performance uint64_t __arch_xprod_64(const uint64_t m, uint64_t n, bool bias) { uint32_t m_lo = m;
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index d3318a3c257775d4f44e8f2eb7911ac52eefecc5..58b3de1f4c2540b6ffabd916948396ac8df9ba8f 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h@@ -248,6 +248,16 @@ struct ftrace_likely_data { */ #define inline inline __gnu_inline __inline_maybe_unused notrace +/* + * Compilers might decide to ignore inline hint. + * Functions that are performance critical can use inline_for_performance. + */ +#ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE +#define inline_for_performance __always_inline +#else +#define inline_for_performance +#endif + /* * gcc provides both __inline__ and __inline as alternate spellings of * the inline keyword, though the latter is undocumented. New kernel
base-commit: e84d960149e71e8d5e4db69775ce31305898ed0c -- 2.52.0.457.g6b5491de43-goog