futex: Allow for compiling out PI support
This makes it possible to preserve basic futex support and compile out the
PI support when RT mutexes are not available.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <dvhart@infradead.org>
Link: http://lkml.kernel.org/r/alpine.LFD.2.20.1708010024190.5981@knanqh.ubzr
diff --git a/init/Kconfig b/init/Kconfig
index 8514b25..5f0ef85 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1275,12 +1275,17 @@
config FUTEX
bool "Enable futex support" if EXPERT
default y
- select RT_MUTEXES
+ imply RT_MUTEXES
help
Disabling this option will cause the kernel to be built without
support for "fast userspace mutexes". The resulting kernel may not
run glibc-based applications correctly.
+config FUTEX_PI
+ bool
+ depends on FUTEX && RT_MUTEXES
+ default y
+
config HAVE_FUTEX_CMPXCHG
bool
depends on FUTEX
