path: root/init
diff options
authorHeiko Carstens <heiko.carstens@de.ibm.com>2014-03-02 13:09:47 +0100
committerThomas Gleixner <tglx@linutronix.de>2014-03-03 11:32:08 +0100
commit03b8c7b623c80af264c4c8d6111e5c6289933666 (patch)
tree7fa99fe8a333d567987e563dfa4ff1cf6ee03f04 /init
parentd2ae2e525ec4e5d58153fb7ff0c6e5873769fa73 (diff)
futex: Allow architectures to skip futex_atomic_cmpxchg_inatomic() test
If an architecture has futex_atomic_cmpxchg_inatomic() implemented and there is no runtime check necessary, allow to skip the test within futex_init(). This allows to get rid of some code which would always give the same result, and also allows the compiler to optimize a couple of if statements away. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Finn Thain <fthain@telegraphics.com.au> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Link: http://lkml.kernel.org/r/20140302120947.GA3641@osiris Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'init')
1 files changed, 7 insertions, 0 deletions
diff --git a/init/Kconfig b/init/Kconfig
index 009a797dd242..d56cb03c1b49 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1387,6 +1387,13 @@ config FUTEX
support for "fast userspace mutexes". The resulting kernel may not
run glibc-based applications correctly.
+ bool
+ help
+ Architectures should select this if futex_atomic_cmpxchg_inatomic()
+ is implemented and always working. This removes a couple of runtime
+ checks.
config EPOLL
bool "Enable eventpoll support" if EXPERT
default y

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