android_kernel_motorola_sm6225/include/linux/rtmutex.h
Ingo Molnar 9a11b49a80 [PATCH] lockdep: better lock debugging
Generic lock debugging:

 - generalized lock debugging framework. For example, a bug in one lock
   subsystem turns off debugging in all lock subsystems.

 - got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from
   the mutex/rtmutex debugging code: it caused way too much prototype
   hackery, and lockdep will give the same information anyway.

 - ability to do silent tests

 - check lock freeing in vfree too.

 - more finegrained debugging options, to allow distributions to
   turn off more expensive debugging features.

There's no separate 'held mutexes' list anymore - but there's a 'held locks'
stack within lockdep, which unifies deadlock detection across all lock
classes.  (this is independent of the lockdep validation stuff - lockdep first
checks whether we are holding a lock already)

Here are the current debugging options:

CONFIG_DEBUG_MUTEXES=y
CONFIG_DEBUG_LOCK_ALLOC=y

which do:

 config DEBUG_MUTEXES
          bool "Mutex debugging, basic checks"

 config DEBUG_LOCK_ALLOC
         bool "Detect incorrect freeing of live mutexes"

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 15:27:01 -07:00

107 lines
3 KiB
C

/*
* RT Mutexes: blocking mutual exclusion locks with PI support
*
* started by Ingo Molnar and Thomas Gleixner:
*
* Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
* Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
*
* This file contains the public data structure and API definitions.
*/
#ifndef __LINUX_RT_MUTEX_H
#define __LINUX_RT_MUTEX_H
#include <linux/linkage.h>
#include <linux/plist.h>
#include <linux/spinlock_types.h>
/*
* The rt_mutex structure
*
* @wait_lock: spinlock to protect the structure
* @wait_list: pilist head to enqueue waiters in priority order
* @owner: the mutex owner
*/
struct rt_mutex {
spinlock_t wait_lock;
struct plist_head wait_list;
struct task_struct *owner;
#ifdef CONFIG_DEBUG_RT_MUTEXES
int save_state;
const char *name, *file;
int line;
void *magic;
#endif
};
struct rt_mutex_waiter;
struct hrtimer_sleeper;
#ifdef CONFIG_DEBUG_RT_MUTEXES
extern int rt_mutex_debug_check_no_locks_freed(const void *from,
unsigned long len);
extern void rt_mutex_debug_check_no_locks_held(struct task_struct *task);
#else
static inline int rt_mutex_debug_check_no_locks_freed(const void *from,
unsigned long len)
{
return 0;
}
# define rt_mutex_debug_check_no_locks_held(task) do { } while (0)
#endif
#ifdef CONFIG_DEBUG_RT_MUTEXES
# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
, .name = #mutexname, .file = __FILE__, .line = __LINE__
# define rt_mutex_init(mutex) __rt_mutex_init(mutex, __FUNCTION__)
extern void rt_mutex_debug_task_free(struct task_struct *tsk);
#else
# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname)
# define rt_mutex_init(mutex) __rt_mutex_init(mutex, NULL)
# define rt_mutex_debug_task_free(t) do { } while (0)
#endif
#define __RT_MUTEX_INITIALIZER(mutexname) \
{ .wait_lock = SPIN_LOCK_UNLOCKED \
, .wait_list = PLIST_HEAD_INIT(mutexname.wait_list, mutexname.wait_lock) \
, .owner = NULL \
__DEBUG_RT_MUTEX_INITIALIZER(mutexname)}
#define DEFINE_RT_MUTEX(mutexname) \
struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname)
/***
* rt_mutex_is_locked - is the mutex locked
* @lock: the mutex to be queried
*
* Returns 1 if the mutex is locked, 0 if unlocked.
*/
static inline int rt_mutex_is_locked(struct rt_mutex *lock)
{
return lock->owner != NULL;
}
extern void __rt_mutex_init(struct rt_mutex *lock, const char *name);
extern void rt_mutex_destroy(struct rt_mutex *lock);
extern void rt_mutex_lock(struct rt_mutex *lock);
extern int rt_mutex_lock_interruptible(struct rt_mutex *lock,
int detect_deadlock);
extern int rt_mutex_timed_lock(struct rt_mutex *lock,
struct hrtimer_sleeper *timeout,
int detect_deadlock);
extern int rt_mutex_trylock(struct rt_mutex *lock);
extern void rt_mutex_unlock(struct rt_mutex *lock);
#ifdef CONFIG_RT_MUTEXES
# define INIT_RT_MUTEXES(tsk) \
.pi_waiters = PLIST_HEAD_INIT(tsk.pi_waiters, tsk.pi_lock), \
INIT_RT_MUTEX_DEBUG(tsk)
#else
# define INIT_RT_MUTEXES(tsk)
#endif
#endif