The patch titled Subject: compiler, clang: always inline when CONFIG_OPTIMIZE_INLINING is disabled has been removed from the -mm tree. Its filename was compiler-clang-always-inline-when-config_optimize_inlining-is-disabled.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: David Rientjes <rientjes@xxxxxxxxxx> Subject: compiler, clang: always inline when CONFIG_OPTIMIZE_INLINING is disabled The motivation of abb2ea7dfd82 ("compiler, clang: suppress warning for unused static inline functions") is to suppress clang's warnings about unused static inline functions. For configs without CONFIG_OPTIMIZE_INLINING enabled, such as any non-x86 architecture, `inline' in the kernel implies that __attribute__((always_inline)) is used. Some code depends on that behavior, see https://lkml.org/lkml/2017/6/13/918: net/built-in.o: In function `__xchg_mb': arch/arm64/include/asm/cmpxchg.h:99: undefined reference to `__compiletime_assert_99' arch/arm64/include/asm/cmpxchg.h:99: undefined reference to `__compiletime_assert_99 The full fix would be to identify these breakages and annotate the functions with __always_inline instead of `inline'. But since we are late in the 4.12-rc cycle, simply carry forward the forced inlining behavior and work toward moving arm64, and other architectures, toward CONFIG_OPTIMIZE_INLINING behavior. Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1706261552200.1075@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx> Reported-by: Sodagudi Prasad <psodagud@xxxxxxxxxxxxxx> Tested-by: Sodagudi Prasad <psodagud@xxxxxxxxxxxxxx> Tested-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/compiler-clang.h | 8 -------- include/linux/compiler-gcc.h | 18 +++++++++++------- 2 files changed, 11 insertions(+), 15 deletions(-) diff -puN include/linux/compiler-clang.h~compiler-clang-always-inline-when-config_optimize_inlining-is-disabled include/linux/compiler-clang.h --- a/include/linux/compiler-clang.h~compiler-clang-always-inline-when-config_optimize_inlining-is-disabled +++ a/include/linux/compiler-clang.h @@ -15,11 +15,3 @@ * with any version that can compile the kernel */ #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) - -/* - * GCC does not warn about unused static inline functions for - * -Wunused-function. This turns out to avoid the need for complex #ifdef - * directives. Suppress the warning in clang as well. - */ -#undef inline -#define inline inline __attribute__((unused)) notrace diff -puN include/linux/compiler-gcc.h~compiler-clang-always-inline-when-config_optimize_inlining-is-disabled include/linux/compiler-gcc.h --- a/include/linux/compiler-gcc.h~compiler-clang-always-inline-when-config_optimize_inlining-is-disabled +++ a/include/linux/compiler-gcc.h @@ -66,18 +66,22 @@ /* * Force always-inline if the user requests it so via the .config, - * or if gcc is too old: + * or if gcc is too old. + * GCC does not warn about unused static inline functions for + * -Wunused-function. This turns out to avoid the need for complex #ifdef + * directives. Suppress the warning in clang as well by using "unused" + * function attribute, which is redundant but not harmful for gcc. */ #if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \ !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4) -#define inline inline __attribute__((always_inline)) notrace -#define __inline__ __inline__ __attribute__((always_inline)) notrace -#define __inline __inline __attribute__((always_inline)) notrace +#define inline inline __attribute__((always_inline,unused)) notrace +#define __inline__ __inline__ __attribute__((always_inline,unused)) notrace +#define __inline __inline __attribute__((always_inline,unused)) notrace #else /* A lot of inline functions can cause havoc with function tracing */ -#define inline inline notrace -#define __inline__ __inline__ notrace -#define __inline __inline notrace +#define inline inline __attribute__((unused)) notrace +#define __inline__ __inline__ __attribute__((unused)) notrace +#define __inline __inline __attribute__((unused)) notrace #endif #define __always_inline inline __attribute__((always_inline)) _ Patches currently in -mm which might be from rientjes@xxxxxxxxxx are mm-vmscan-avoid-thrashing-anon-lru-when-free-file-is-low.patch mm-vmpressure-pass-through-notification-support.patch mm-hugetlb-schedule-when-potentially-allocating-many-hugepages.patch fs-epoll-short-circuit-fetching-events-if-thread-has-been-killed.patch