From d1843ac456d8b9cde30ebc4fe9c5337df10da82e Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Tue, 14 May 2019 15:42:25 -0700 Subject: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING Commit 60a3cdd06394 ("x86: add optimized inlining") introduced CONFIG_OPTIMIZE_INLINING, but it has been available only for x86. The idea is obviously arch-agnostic. This commit moves the config entry from arch/x86/Kconfig.debug to lib/Kconfig.debug so that all architectures can benefit from it. This can make a huge difference in kernel image size especially when CONFIG_OPTIMIZE_FOR_SIZE is enabled. For example, I got 3.5% smaller arm64 kernel for v5.1-rc1. dec file 18983424 arch/arm64/boot/Image.before 18321920 arch/arm64/boot/Image.after This also slightly improves the "Kernel hacking" Kconfig menu as e61aca5158a8 ("Merge branch 'kconfig-diet' from Dave Hansen') suggested; this config option would be a good fit in the "compiler option" menu. Link: http://lkml.kernel.org/r/20190423034959.13525-12-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada Acked-by: Borislav Petkov Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: Boris Brezillon Cc: Brian Norris Cc: Christophe Leroy Cc: David Woodhouse Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Marek Vasut Cc: Mark Rutland Cc: Mathieu Malaterre Cc: Miquel Raynal Cc: Paul Mackerras Cc: Ralf Baechle Cc: Richard Weinberger Cc: Russell King Cc: Stefan Agner Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [kdrag0n: Backported to k4.14] Signed-off-by: Danny Lin --- arch/x86/Kconfig | 3 --- arch/x86/Kconfig.debug | 14 -------------- include/linux/compiler-gcc.h | 3 +-- lib/Kconfig.debug | 14 ++++++++++++++ 4 files changed, 15 insertions(+), 19 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index a9b831061e84..50d18514b51b 100755 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -296,9 +296,6 @@ config ZONE_DMA32 config AUDIT_ARCH def_bool y if X86_64 -config ARCH_SUPPORTS_OPTIMIZED_INLINING - def_bool y - config ARCH_SUPPORTS_DEBUG_PAGEALLOC def_bool y diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index bec0952c5595..cb77a9e9f9fe 100755 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -284,20 +284,6 @@ config CPA_DEBUG ---help--- Do change_page_attr() self-tests every 30 seconds. -config OPTIMIZE_INLINING - bool "Allow gcc to uninline functions marked 'inline'" - ---help--- - This option determines if the kernel forces gcc to inline the functions - developers have marked 'inline'. Doing so takes away freedom from gcc to - do what it thinks is best, which is desirable for the gcc 3.x series of - compilers. The gcc 4.x series have a rewritten inlining algorithm and - enabling this option will generate a smaller kernel there. Hopefully - this algorithm is so good that allowing gcc 4.x and above to make the - decision will become the default in the future. Until then this option - is there to test gcc for this. - - If unsure, say N. - config DEBUG_ENTRY bool "Debug low-level entry code" depends on DEBUG_KERNEL diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index 02cb5761fef4..224c524243fe 100755 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -90,8 +90,7 @@ * of extern inline functions at link time. * A lot of inline functions can cause havoc with function tracing. */ -#if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \ - !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4) +#if !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4) #define inline \ inline __attribute__((always_inline, unused)) notrace __gnu_inline #else diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 50f0d766e7bc..1a6a82117b2f 100755 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -335,6 +335,20 @@ config HEADERS_CHECK exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in your build tree), to make sure they're suitable. +config OPTIMIZE_INLINING + bool "Allow compiler to uninline functions marked 'inline'" + help + This option determines if the kernel forces gcc to inline the functions + developers have marked 'inline'. Doing so takes away freedom from gcc to + do what it thinks is best, which is desirable for the gcc 3.x series of + compilers. The gcc 4.x series have a rewritten inlining algorithm and + enabling this option will generate a smaller kernel there. Hopefully + this algorithm is so good that allowing gcc 4.x and above to make the + decision will become the default in the future. Until then this option + is there to test gcc for this. + + If unsure, say N. + config DEBUG_SECTION_MISMATCH bool "Enable full Section mismatch analysis" help