Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=c...
Commit: 60a3cdd0639473c79c253bc08c8ef8f882cca107
Parent: b1721d0da266b4af8cb4419473b4ca36206ab200
Author: Ingo Molnar <mingo@elte.hu>
AuthorDate: Mon Mar 3 12:38:52 2008 +0100
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Sat Apr 26 17:44:55 2008 +0200
x86: add optimized inlining
add CONFIG_OPTIMIZE_INLINING=y.
allow gcc to optimize the kernel image's size by uninlining
functions that have been marked 'inline'. Previously gcc was
forced by Linux to always-inline these functions via a gcc
attribute:
#define inline inline __attribute__((always_inline))
Especially when the user has already selected
CONFIG_OPTIMIZE_FOR_SIZE=y this can make a huge difference in
kernel image size (using a standard Fedora .config):
text data bss dec hex filename
5613924 562708 3854336 10030968 990f78 vmlinux.before
5486689 562708 3854336 9903733 971e75 vmlinux.after
that's a 2.3% text size reduction (!).
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/Kconfig.debug | 13 +++++++++++++
arch/x86/configs/i386_defconfig | 1 +
arch/x86/configs/x86_64_defconfig | 1 +
include/linux/compiler-gcc.h | 12 +++++++++---
4 files changed, 24 insertions(+), 3 deletions(-)
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 239fd9f..5b1979a 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -257,3 +257,16 @@ config CPA_DEBUG
Do change_page_attr() self-tests every 30 seconds.
endmenu
+
+config OPTIMIZE_INLINING
+ bool "Allow gcc to uninline functions marked 'inline'"
+ default y
+ help
+ This option determines if the kernel forces gcc to inline the functions
+ developers have marked 'inline'. Doing so takes away freedom fr...
