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authorMasahiro Yamada <yamada.masahiro@socionext.com>2019-05-14 15:42:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-14 19:52:48 -0700
commit9012d011660ea5cf2a623e1de207a2bc0ca6936d (patch)
treef8262000f8891b8587b5c7442a3bec172aa8dbc4 /lib
parentefc344c57e39754416731e24e1eadd7d9b9f335e (diff)
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 <yamada.masahiro@socionext.com> Acked-by: Borislav Petkov <bp@suse.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Boris Brezillon <bbrezillon@kernel.org> Cc: Brian Norris <computersforpeace@gmail.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Marek Vasut <marek.vasut@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Malaterre <malat@debian.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Stefan Agner <stefan@agner.ch> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig.debug14
1 files changed, 14 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index d695ec1477f3..d5411a7484f6 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -318,6 +318,20 @@ 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