summaryrefslogtreecommitdiff
path: root/init
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2016-05-26 22:01:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-26 22:01:22 -0700
commit5b26fc8824da15a2fe9df89338a5a3cad41ba8ee (patch)
tree04dd34173591e2275a754053c86b06cc1e72cebe /init
parente12fab28df1d7ae9369839a3af260a41447a5e79 (diff)
parentc9c6837d39311b0cc14cdbe7c18e815ab44aefb1 (diff)
downloadlinux-5b26fc8824da15a2fe9df89338a5a3cad41ba8ee.tar.gz
Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild updates from Michal Marek: - new option CONFIG_TRIM_UNUSED_KSYMS which does a two-pass build and unexports symbols which are not used in the current config [Nicolas Pitre] - several kbuild rule cleanups [Masahiro Yamada] - warning option adjustments for gcov etc [Arnd Bergmann] - a few more small fixes * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (31 commits) kbuild: move -Wunused-const-variable to W=1 warning level kbuild: fix if_change and friends to consider argument order kbuild: fix adjust_autoksyms.sh for modules that need only one symbol kbuild: fix ksym_dep_filter when multiple EXPORT_SYMBOL() on the same line gcov: disable -Wmaybe-uninitialized warning gcov: disable tree-loop-im to reduce stack usage gcov: disable for COMPILE_TEST Kbuild: disable 'maybe-uninitialized' warning for CONFIG_PROFILE_ALL_BRANCHES Kbuild: change CC_OPTIMIZE_FOR_SIZE definition kbuild: forbid kernel directory to contain spaces and colons kbuild: adjust ksym_dep_filter for some cmd_* renames kbuild: Fix dependencies for final vmlinux link kbuild: better abstract vmlinux sequential prerequisites kbuild: fix call to adjust_autoksyms.sh when output directory specified kbuild: Get rid of KBUILD_STR kbuild: rename cmd_as_s_S to cmd_cpp_s_S kbuild: rename cmd_cc_i_c to cmd_cpp_i_c kbuild: drop redundant "PHONY += FORCE" kbuild: delete unnecessary "@:" kbuild: mark help target as PHONY ...
Diffstat (limited to 'init')
-rw-r--r--init/Kconfig29
1 files changed, 29 insertions, 0 deletions
diff --git a/init/Kconfig b/init/Kconfig
index a9c4aefd5436..f755a602d4a1 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1306,6 +1306,17 @@ source "usr/Kconfig"
endif
+choice
+ prompt "Compiler optimization level"
+ default CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
+
+config CC_OPTIMIZE_FOR_PERFORMANCE
+ bool "Optimize for performance"
+ help
+ This is the default optimization level for the kernel, building
+ with the "-O2" compiler flag for best performance and most
+ helpful compile-time warnings.
+
config CC_OPTIMIZE_FOR_SIZE
bool "Optimize for size"
help
@@ -1314,6 +1325,8 @@ config CC_OPTIMIZE_FOR_SIZE
If unsure, say N.
+endchoice
+
config SYSCTL
bool
@@ -2049,6 +2062,22 @@ config MODULE_COMPRESS_XZ
endchoice
+config TRIM_UNUSED_KSYMS
+ bool "Trim unused exported kernel symbols"
+ depends on MODULES && !UNUSED_SYMBOLS
+ help
+ The kernel and some modules make many symbols available for
+ other modules to use via EXPORT_SYMBOL() and variants. Depending
+ on the set of modules being selected in your kernel configuration,
+ many of those exported symbols might never be used.
+
+ This option allows for unused exported symbols to be dropped from
+ the build. In turn, this provides the compiler more opportunities
+ (especially when using LTO) for optimizing the code and reducing
+ binary size. This might have some security advantages as well.
+
+ If unsure say N.
+
endif # MODULES
config MODULES_TREE_LOOKUP