rtmutex: Delete scriptable tester

No one uses this anymore, and this is not the first time the
idea of replacing it with a (now possible) userspace side.
Lock stealing logic was removed long ago in when the lock
was granted to the highest prio.

Signed-off-by: Davidlohr Bueso <[email protected]>
Cc: Darren Hart <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>

Author: Davidlohr Bueso

arch/parisc/configs/c8000_defconfig

@@ -242,7 +242,6 @@ CONFIG_LOCKUP_DETECTOR=y
 CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
 CONFIG_PANIC_ON_OOPS=y
 CONFIG_DEBUG_RT_MUTEXES=y
-CONFIG_RT_MUTEX_TESTER=y
 CONFIG_PROVE_RCU_DELAY=y
 CONFIG_DEBUG_BLOCK_EXT_DEVT=y
 CONFIG_LATENCYTOP=y

arch/parisc/configs/generic-32bit_defconfig

@@ -295,7 +295,6 @@ CONFIG_DEBUG_SHIRQ=y
 CONFIG_DETECT_HUNG_TASK=y
 CONFIG_TIMER_STATS=y
 CONFIG_DEBUG_RT_MUTEXES=y
-CONFIG_RT_MUTEX_TESTER=y
 CONFIG_DEBUG_SPINLOCK=y
 CONFIG_DEBUG_MUTEXES=y
 CONFIG_RCU_CPU_STALL_INFO=y

arch/xtensa/configs/iss_defconfig

@@ -616,7 +616,6 @@ CONFIG_SCHED_DEBUG=y
 # CONFIG_SLUB_DEBUG_ON is not set
 # CONFIG_SLUB_STATS is not set
 # CONFIG_DEBUG_RT_MUTEXES is not set
-# CONFIG_RT_MUTEX_TESTER is not set
 # CONFIG_DEBUG_SPINLOCK is not set
 # CONFIG_DEBUG_MUTEXES is not set
 # CONFIG_DEBUG_SPINLOCK_SLEEP is not set

kernel/locking/Makefile

@@ -20,7 +20,6 @@ obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
 obj-$(CONFIG_QUEUED_SPINLOCKS) += qspinlock.o
 obj-$(CONFIG_RT_MUTEXES) += rtmutex.o
 obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o
-obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o
 obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o
 obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
 obj-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o

kernel/locking/rtmutex-tester.c

@@ -1120,7 +1120,7 @@ __rt_mutex_slowlock(struct rt_mutex *lock, int state,
 
 		debug_rt_mutex_print_deadlock(waiter);
 
-		schedule_rt_mutex(lock);
+		schedule();
 
 		raw_spin_lock(&lock->wait_lock);
 		set_current_state(state);

kernel/locking/rtmutex.c

@@ -14,28 +14,6 @@
 
 #include <linux/rtmutex.h>
 
-/*
- * The rtmutex in kernel tester is independent of rtmutex debugging. We
- * call schedule_rt_mutex_test() instead of schedule() for the tasks which
- * belong to the tester. That way we can delay the wakeup path of those
- * threads to provoke lock stealing and testing of  complex boosting scenarios.
- */
-#ifdef CONFIG_RT_MUTEX_TESTER
-
-extern void schedule_rt_mutex_test(struct rt_mutex *lock);
-
-#define schedule_rt_mutex(_lock)				\
-  do {								\
-	if (!(current->flags & PF_MUTEX_TESTER))		\
-		schedule();					\
-	else							\
-		schedule_rt_mutex_test(_lock);			\
-  } while (0)
-
-#else
-# define schedule_rt_mutex(_lock)			schedule()
-#endif
-
 /*
  * This is the control structure for tasks blocked on a rt_mutex,
  * which is allocated on the kernel stack on of the blocked task.

kernel/locking/rtmutex_common.h

@@ -916,12 +916,6 @@ config DEBUG_RT_MUTEXES
 	 This allows rt mutex semantics violations and rt mutex related
 	 deadlocks (lockups) to be detected and reported automatically.
 
-config RT_MUTEX_TESTER
-	bool "Built-in scriptable tester for rt-mutexes"
-	depends on DEBUG_KERNEL && RT_MUTEXES && BROKEN
-	help
-	  This option enables a rt-mutex tester.
-
 config DEBUG_SPINLOCK
 	bool "Spinlock and rw-lock debugging: basic checks"
 	depends on DEBUG_KERNEL