[PATCH] locking: Enable RT_MUTEXES by default on PREEMPT_RT.

[Sebastian Andrzej Siewior]

The CONFIG_RT_MUTEXES option is enabled by CONFIG_FUTEX and CONFIG_I2C.
If both are disabled then a CONFIG_PREEMPT_RT build fails to compile.
It is not possible to have a PREEMPT_RT kernel without RT_MUTEX support
because RT_MUTEX based locking is always used.

Enable CONFIG_RT_MUTEXES by default on PREEMPT_RT builds.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
 init/Kconfig |    1 +
 1 file changed, 1 insertion(+)

--- a/init/Kconfig
+++ b/init/Kconfig
@@ -2058,6 +2058,7 @@ source "arch/Kconfig"
 
 config RT_MUTEXES
 	bool
+	default y if PREEMPT_RT
 
 config BASE_SMALL
 	int