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Commit 23f78d4a authored by Ingo Molnar's avatar Ingo Molnar Committed by Linus Torvalds
Browse files

[PATCH] pi-futex: rt mutex core 



Core functions for the rt-mutex subsystem.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent b29739f9

include/linux/init_task.h

+1 −0
Original line number Diff line number Diff line
@@ -124,6 +124,7 @@ extern struct group_info init_groups; 
	.cpu_timers	= INIT_CPU_TIMERS(tsk.cpu_timers),		\

	.fs_excl	= ATOMIC_INIT(0),				\

	.pi_lock	= SPIN_LOCK_UNLOCKED,				\

	INIT_RT_MUTEXES(tsk)						\

}

include/linux/rtmutex.h

0 → 100644
+104 −0
Original line number Diff line number Diff line 
/*

 * 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;

	struct list_head	held_list_entry;

	unsigned long		acquire_ip;

	const char 		*name, *file;

	int			line;

	void			*magic;

#endif

};



struct rt_mutex_waiter;

struct hrtimer_sleeper;



#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_DEBUG_RT_MUTEXES

# define INIT_RT_MUTEX_DEBUG(tsk)					\

	.held_list_head	= LIST_HEAD_INIT(tsk.held_list_head),		\

	.held_list_lock	= SPIN_LOCK_UNLOCKED

#else

# define INIT_RT_MUTEX_DEBUG(tsk)

#endif



#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

include/linux/sched.h

+12 −0
Original line number Diff line number Diff line
@@ -73,6 +73,7 @@ struct sched_param { 
#include <linux/seccomp.h>

#include <linux/rcupdate.h>

#include <linux/futex.h>

#include <linux/rtmutex.h>



#include <linux/time.h>

#include <linux/param.h>
@@ -858,6 +859,17 @@ struct task_struct { 
	/* Protection of the PI data structures: */

	spinlock_t pi_lock;



#ifdef CONFIG_RT_MUTEXES

	/* PI waiters blocked on a rt_mutex held by this task */

	struct plist_head pi_waiters;

	/* Deadlock detection and priority inheritance handling */

	struct rt_mutex_waiter *pi_blocked_on;

# ifdef CONFIG_DEBUG_RT_MUTEXES

	spinlock_t held_list_lock;

	struct list_head held_list_head;

# endif

#endif



#ifdef CONFIG_DEBUG_MUTEXES

	/* mutex deadlock detection */

	struct mutex_waiter *blocked_on;

include/linux/sysctl.h

+1 −0
Original line number Diff line number Diff line
@@ -149,6 +149,7 @@ enum 
	KERN_ACPI_VIDEO_FLAGS=71, /* int: flags for setting up video after ACPI sleep */

	KERN_IA64_UNALIGNED=72, /* int: ia64 unaligned userland trap enable */

	KERN_COMPAT_LOG=73,	/* int: print compat layer  messages */

	KERN_MAX_LOCK_DEPTH=74,

};

init/Kconfig

+5 −0
Original line number Diff line number Diff line
@@ -339,9 +339,14 @@ config BASE_FULL 
	  kernel data structures. This saves memory on small machines,

	  but may reduce performance.



config RT_MUTEXES

	boolean

	select PLIST



config FUTEX

	bool "Enable futex support" if EMBEDDED

	default y

	select RT_MUTEXES

	help

	  Disabling this option will cause the kernel to be built without

	  support for "fast userspace mutexes".  The resulting kernel may not