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| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2014-03-02 13:09:47 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2014-03-03 11:32:08 +0100 |
| commit | 03b8c7b623c80af264c4c8d6111e5c6289933666 (patch) | |
| tree | 7fa99fe8a333d567987e563dfa4ff1cf6ee03f04 /init | |
| parent | d2ae2e525ec4e5d58153fb7ff0c6e5873769fa73 (diff) | |
| download | lwn-03b8c7b623c80af264c4c8d6111e5c6289933666.tar.gz lwn-03b8c7b623c80af264c4c8d6111e5c6289933666.zip | |
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')
| -rw-r--r-- | init/Kconfig | 7 |
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. +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 |