From cee41ea056923d9fca61bf3ccccaf7f245d2ea7b Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Sun, 2 Mar 2014 13:09:47 +0100 Subject: futex: Allow architectures to skip futex_atomic_cmpxchg_inatomic() test commit 03b8c7b623c80af264c4c8d6111e5c6289933666 upstream. 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 Cc: Finn Thain Cc: Geert Uytterhoeven Link: http://lkml.kernel.org/r/20140302120947.GA3641@osiris Signed-off-by: Thomas Gleixner [geert: Backported to v3.10..v3.13] Signed-off-by: Geert Uytterhoeven Signed-off-by: Jiri Slaby --- init/Kconfig | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index 3ecd8a1178f1..d42dc7c6ba64 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1406,6 +1406,13 @@ config FUTEX support for "fast userspace mutexes". The resulting kernel may not run glibc-based applications correctly. +config HAVE_FUTEX_CMPXCHG + 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 -- cgit v1.2.3