Commit c4ef144a authored by Ingo Molnar's avatar Ingo Molnar
Browse files

Merge branch 'tracing/ftrace' into tracing/core

parents a1be621d efed792d
......@@ -27,33 +27,37 @@ lock-class.
State
-----
The validator tracks lock-class usage history into 5 separate state bits:
The validator tracks lock-class usage history into 4n + 1 separate state bits:
- 'ever held in hardirq context' [ == hardirq-safe ]
- 'ever held in softirq context' [ == softirq-safe ]
- 'ever held with hardirqs enabled' [ == hardirq-unsafe ]
- 'ever held with softirqs and hardirqs enabled' [ == softirq-unsafe ]
- 'ever held in STATE context'
- 'ever head as readlock in STATE context'
- 'ever head with STATE enabled'
- 'ever head as readlock with STATE enabled'
Where STATE can be either one of (kernel/lockdep_states.h)
- hardirq
- softirq
- reclaim_fs
- 'ever used' [ == !unused ]
When locking rules are violated, these 4 state bits are presented in the
locking error messages, inside curlies. A contrived example:
When locking rules are violated, these state bits are presented in the
locking error messages, inside curlies. A contrived example:
modprobe/2287 is trying to acquire lock:
(&sio_locks[i].lock){--..}, at: [<c02867fd>] mutex_lock+0x21/0x24
(&sio_locks[i].lock){-.-...}, at: [<c02867fd>] mutex_lock+0x21/0x24
but task is already holding lock:
(&sio_locks[i].lock){--..}, at: [<c02867fd>] mutex_lock+0x21/0x24
(&sio_locks[i].lock){-.-...}, at: [<c02867fd>] mutex_lock+0x21/0x24
The bit position indicates hardirq, softirq, hardirq-read,
softirq-read respectively, and the character displayed in each
indicates:
The bit position indicates STATE, STATE-read, for each of the states listed
above, and the character displayed in each indicates:
'.' acquired while irqs disabled
'+' acquired in irq context
'-' acquired with irqs enabled
'?' read acquired in irq context with irqs enabled.
'?' acquired in irq context with irqs enabled.
Unused mutexes cannot be part of the cause of an error.
......
......@@ -20,43 +20,10 @@ struct lockdep_map;
#include <linux/stacktrace.h>
/*
* Lock-class usage-state bits:
* We'd rather not expose kernel/lockdep_states.h this wide, but we do need
* the total number of states... :-(
*/
enum lock_usage_bit
{
LOCK_USED = 0,
LOCK_USED_IN_HARDIRQ,
LOCK_USED_IN_SOFTIRQ,
LOCK_ENABLED_SOFTIRQS,
LOCK_ENABLED_HARDIRQS,
LOCK_USED_IN_HARDIRQ_READ,
LOCK_USED_IN_SOFTIRQ_READ,
LOCK_ENABLED_SOFTIRQS_READ,
LOCK_ENABLED_HARDIRQS_READ,
LOCK_USAGE_STATES
};
/*
* Usage-state bitmasks:
*/
#define LOCKF_USED (1 << LOCK_USED)
#define LOCKF_USED_IN_HARDIRQ (1 << LOCK_USED_IN_HARDIRQ)
#define LOCKF_USED_IN_SOFTIRQ (1 << LOCK_USED_IN_SOFTIRQ)
#define LOCKF_ENABLED_HARDIRQS (1 << LOCK_ENABLED_HARDIRQS)
#define LOCKF_ENABLED_SOFTIRQS (1 << LOCK_ENABLED_SOFTIRQS)
#define LOCKF_ENABLED_IRQS (LOCKF_ENABLED_HARDIRQS | LOCKF_ENABLED_SOFTIRQS)
#define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ | LOCKF_USED_IN_SOFTIRQ)
#define LOCKF_USED_IN_HARDIRQ_READ (1 << LOCK_USED_IN_HARDIRQ_READ)
#define LOCKF_USED_IN_SOFTIRQ_READ (1 << LOCK_USED_IN_SOFTIRQ_READ)
#define LOCKF_ENABLED_HARDIRQS_READ (1 << LOCK_ENABLED_HARDIRQS_READ)
#define LOCKF_ENABLED_SOFTIRQS_READ (1 << LOCK_ENABLED_SOFTIRQS_READ)
#define LOCKF_ENABLED_IRQS_READ \
(LOCKF_ENABLED_HARDIRQS_READ | LOCKF_ENABLED_SOFTIRQS_READ)
#define LOCKF_USED_IN_IRQ_READ \
(LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ)
#define XXX_LOCK_USAGE_STATES (1+3*4)
#define MAX_LOCKDEP_SUBCLASSES 8UL
......@@ -97,7 +64,7 @@ struct lock_class {
* IRQ/softirq usage tracking bits:
*/
unsigned long usage_mask;
struct stack_trace usage_traces[LOCK_USAGE_STATES];
struct stack_trace usage_traces[XXX_LOCK_USAGE_STATES];
/*
* These fields represent a directed graph of lock dependencies,
......@@ -324,7 +291,11 @@ static inline void lock_set_subclass(struct lockdep_map *lock,
lock_set_class(lock, lock->name, lock->key, subclass, ip);
}
# define INIT_LOCKDEP .lockdep_recursion = 0,
extern void lockdep_set_current_reclaim_state(gfp_t gfp_mask);
extern void lockdep_clear_current_reclaim_state(void);
extern void lockdep_trace_alloc(gfp_t mask);
# define INIT_LOCKDEP .lockdep_recursion = 0, .lockdep_reclaim_gfp = 0,
#define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0)
......@@ -342,6 +313,9 @@ static inline void lockdep_on(void)
# define lock_release(l, n, i) do { } while (0)
# define lock_set_class(l, n, k, s, i) do { } while (0)
# define lock_set_subclass(l, s, i) do { } while (0)
# define lockdep_set_current_reclaim_state(g) do { } while (0)
# define lockdep_clear_current_reclaim_state() do { } while (0)
# define lockdep_trace_alloc(g) do { } while (0)
# define lockdep_init() do { } while (0)
# define lockdep_info() do { } while (0)
# define lockdep_init_map(lock, name, key, sub) \
......
......@@ -50,8 +50,10 @@ struct mutex {
atomic_t count;
spinlock_t wait_lock;
struct list_head wait_list;
#ifdef CONFIG_DEBUG_MUTEXES
#if defined(CONFIG_DEBUG_MUTEXES) || defined(CONFIG_SMP)
struct thread_info *owner;
#endif
#ifdef CONFIG_DEBUG_MUTEXES
const char *name;
void *magic;
#endif
......@@ -68,7 +70,6 @@ struct mutex_waiter {
struct list_head list;
struct task_struct *task;
#ifdef CONFIG_DEBUG_MUTEXES
struct mutex *lock;
void *magic;
#endif
};
......
......@@ -121,6 +121,9 @@ unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu);
u64 ring_buffer_time_stamp(int cpu);
void ring_buffer_normalize_time_stamp(int cpu, u64 *ts);
size_t ring_buffer_page_len(void *page);
/*
* The below functions are fine to use outside the tracing facility.
*/
......@@ -138,8 +141,8 @@ static inline int tracing_is_on(void) { return 0; }
void *ring_buffer_alloc_read_page(struct ring_buffer *buffer);
void ring_buffer_free_read_page(struct ring_buffer *buffer, void *data);
int ring_buffer_read_page(struct ring_buffer *buffer,
void **data_page, int cpu, int full);
int ring_buffer_read_page(struct ring_buffer *buffer, void **data_page,
size_t len, int cpu, int full);
enum ring_buffer_flags {
RB_FL_OVERWRITE = 1 << 0,
......
......@@ -333,7 +333,9 @@ extern signed long schedule_timeout(signed long timeout);
extern signed long schedule_timeout_interruptible(signed long timeout);
extern signed long schedule_timeout_killable(signed long timeout);
extern signed long schedule_timeout_uninterruptible(signed long timeout);
asmlinkage void __schedule(void);
asmlinkage void schedule(void);
extern int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner);
struct nsproxy;
struct user_namespace;
......@@ -1330,6 +1332,7 @@ struct task_struct {
int lockdep_depth;
unsigned int lockdep_recursion;
struct held_lock held_locks[MAX_LOCK_DEPTH];
gfp_t lockdep_reclaim_gfp;
#endif
/* journalling filesystem info */
......
......@@ -5,6 +5,7 @@
#include <linux/ktime.h>
#include <linux/stddef.h>
#include <linux/debugobjects.h>
#include <linux/stringify.h>
struct tvec_base;
......@@ -21,52 +22,126 @@ struct timer_list {
char start_comm[16];
int start_pid;
#endif
#ifdef CONFIG_LOCKDEP
struct lockdep_map lockdep_map;
#endif
};
extern struct tvec_base boot_tvec_bases;
#ifdef CONFIG_LOCKDEP
/*
* NB: because we have to copy the lockdep_map, setting the lockdep_map key
* (second argument) here is required, otherwise it could be initialised to
* the copy of the lockdep_map later! We use the pointer to and the string
* "<file>:<line>" as the key resp. the name of the lockdep_map.
*/
#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn) \
.lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
#else
#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
#endif
#define TIMER_INITIALIZER(_function, _expires, _data) { \
.entry = { .prev = TIMER_ENTRY_STATIC }, \
.function = (_function), \
.expires = (_expires), \
.data = (_data), \
.base = &boot_tvec_bases, \
__TIMER_LOCKDEP_MAP_INITIALIZER( \
__FILE__ ":" __stringify(__LINE__)) \
}
#define DEFINE_TIMER(_name, _function, _expires, _data) \
struct timer_list _name = \
TIMER_INITIALIZER(_function, _expires, _data)
void init_timer(struct timer_list *timer);
void init_timer_deferrable(struct timer_list *timer);
void init_timer_key(struct timer_list *timer,
const char *name,
struct lock_class_key *key);
void init_timer_deferrable_key(struct timer_list *timer,
const char *name,
struct lock_class_key *key);
#ifdef CONFIG_LOCKDEP
#define init_timer(timer) \
do { \
static struct lock_class_key __key; \
init_timer_key((timer), #timer, &__key); \
} while (0)
#define init_timer_deferrable(timer) \
do { \
static struct lock_class_key __key; \
init_timer_deferrable_key((timer), #timer, &__key); \
} while (0)
#define init_timer_on_stack(timer) \
do { \
static struct lock_class_key __key; \
init_timer_on_stack_key((timer), #timer, &__key); \
} while (0)
#define setup_timer(timer, fn, data) \
do { \
static struct lock_class_key __key; \
setup_timer_key((timer), #timer, &__key, (fn), (data));\
} while (0)
#define setup_timer_on_stack(timer, fn, data) \
do { \
static struct lock_class_key __key; \
setup_timer_on_stack_key((timer), #timer, &__key, \
(fn), (data)); \
} while (0)
#else
#define init_timer(timer)\
init_timer_key((timer), NULL, NULL)
#define init_timer_deferrable(timer)\
init_timer_deferrable_key((timer), NULL, NULL)
#define init_timer_on_stack(timer)\
init_timer_on_stack_key((timer), NULL, NULL)
#define setup_timer(timer, fn, data)\
setup_timer_key((timer), NULL, NULL, (fn), (data))
#define setup_timer_on_stack(timer, fn, data)\
setup_timer_on_stack_key((timer), NULL, NULL, (fn), (data))
#endif
#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
extern void init_timer_on_stack(struct timer_list *timer);
extern void init_timer_on_stack_key(struct timer_list *timer,
const char *name,
struct lock_class_key *key);
extern void destroy_timer_on_stack(struct timer_list *timer);
#else
static inline void destroy_timer_on_stack(struct timer_list *timer) { }
static inline void init_timer_on_stack(struct timer_list *timer)
static inline void init_timer_on_stack_key(struct timer_list *timer,
const char *name,
struct lock_class_key *key)
{
init_timer(timer);
init_timer_key(timer, name, key);
}
#endif
static inline void setup_timer(struct timer_list * timer,
static inline void setup_timer_key(struct timer_list * timer,
const char *name,
struct lock_class_key *key,
void (*function)(unsigned long),
unsigned long data)
{
timer->function = function;
timer->data = data;
init_timer(timer);
init_timer_key(timer, name, key);
}
static inline void setup_timer_on_stack(struct timer_list *timer,
static inline void setup_timer_on_stack_key(struct timer_list *timer,
const char *name,
struct lock_class_key *key,
void (*function)(unsigned long),
unsigned long data)
{
timer->function = function;
timer->data = data;
init_timer_on_stack(timer);
init_timer_on_stack_key(timer, name, key);
}
/**
......
#ifndef _TRACE_LOCKDEP_H
#define _TRACE_LOCKDEP_H
#include <linux/lockdep.h>
#include <linux/tracepoint.h>
#include <trace/lockdep_event_types.h>
#endif
#ifndef TRACE_EVENT_FORMAT
# error Do not include this file directly.
# error Unless you know what you are doing.
#endif
#undef TRACE_SYSTEM
#define TRACE_SYSTEM lock
#ifdef CONFIG_LOCKDEP
TRACE_FORMAT(lock_acquire,
TPPROTO(struct lockdep_map *lock, unsigned int subclass,
int trylock, int read, int check,
struct lockdep_map *next_lock, unsigned long ip),
TPARGS(lock, subclass, trylock, read, check, next_lock, ip),
TPFMT("%s%s%s", trylock ? "try " : "",
read ? "read " : "", lock->name)
);
TRACE_FORMAT(lock_release,
TPPROTO(struct lockdep_map *lock, int nested, unsigned long ip),
TPARGS(lock, nested, ip),
TPFMT("%s", lock->name)
);
#ifdef CONFIG_LOCK_STAT
TRACE_FORMAT(lock_contended,
TPPROTO(struct lockdep_map *lock, unsigned long ip),
TPARGS(lock, ip),
TPFMT("%s", lock->name)
);
TRACE_FORMAT(lock_acquired,
TPPROTO(struct lockdep_map *lock, unsigned long ip),
TPARGS(lock, ip),
TPFMT("%s", lock->name)
);
#endif
#endif
#undef TRACE_SYSTEM
......@@ -2,3 +2,4 @@
#include <trace/sched_event_types.h>
#include <trace/irq_event_types.h>
#include <trace/lockdep_event_types.h>
......@@ -2,3 +2,4 @@
#include <trace/sched.h>
#include <trace/irq.h>
#include <trace/lockdep.h>
This diff is collapsed.
......@@ -6,6 +6,45 @@
* lockdep subsystem internal functions and variables.
*/
/*
* Lock-class usage-state bits:
*/
enum lock_usage_bit {
#define LOCKDEP_STATE(__STATE) \
LOCK_USED_IN_##__STATE, \
LOCK_USED_IN_##__STATE##_READ, \
LOCK_ENABLED_##__STATE, \
LOCK_ENABLED_##__STATE##_READ,
#include "lockdep_states.h"
#undef LOCKDEP_STATE
LOCK_USED,
LOCK_USAGE_STATES
};
/*
* Usage-state bitmasks:
*/
#define __LOCKF(__STATE) LOCKF_##__STATE = (1 << LOCK_##__STATE),
enum {
#define LOCKDEP_STATE(__STATE) \
__LOCKF(USED_IN_##__STATE) \
__LOCKF(USED_IN_##__STATE##_READ) \
__LOCKF(ENABLED_##__STATE) \
__LOCKF(ENABLED_##__STATE##_READ)
#include "lockdep_states.h"
#undef LOCKDEP_STATE
__LOCKF(USED)
};
#define LOCKF_ENABLED_IRQ (LOCKF_ENABLED_HARDIRQ | LOCKF_ENABLED_SOFTIRQ)
#define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ | LOCKF_USED_IN_SOFTIRQ)
#define LOCKF_ENABLED_IRQ_READ \
(LOCKF_ENABLED_HARDIRQ_READ | LOCKF_ENABLED_SOFTIRQ_READ)
#define LOCKF_USED_IN_IRQ_READ \
(LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ)
/*
* MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
* we track.
......@@ -31,8 +70,10 @@
extern struct list_head all_lock_classes;
extern struct lock_chain lock_chains[];
extern void
get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, char *c4);
#define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2)
extern void get_usage_chars(struct lock_class *class,
char usage[LOCK_USAGE_CHARS]);
extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str);
......
......@@ -84,7 +84,7 @@ static int l_show(struct seq_file *m, void *v)
{
struct lock_class *class = v;
struct lock_list *entry;
char c1, c2, c3, c4;
char usage[LOCK_USAGE_CHARS];
if (v == SEQ_START_TOKEN) {
seq_printf(m, "all lock classes:\n");
......@@ -100,8 +100,8 @@ static int l_show(struct seq_file *m, void *v)
seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class));
#endif
get_usage_chars(class, &c1, &c2, &c3, &c4);
seq_printf(m, " %c%c%c%c", c1, c2, c3, c4);
get_usage_chars(class, usage);
seq_printf(m, " %s", usage);
seq_printf(m, ": ");
print_name(m, class);
......@@ -300,27 +300,27 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
nr_uncategorized++;
if (class->usage_mask & LOCKF_USED_IN_IRQ)
nr_irq_safe++;
if (class->usage_mask & LOCKF_ENABLED_IRQS)
if (class->usage_mask & LOCKF_ENABLED_IRQ)
nr_irq_unsafe++;
if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
nr_softirq_safe++;
if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS)
if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ)
nr_softirq_unsafe++;
if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
nr_hardirq_safe++;
if (class->usage_mask & LOCKF_ENABLED_HARDIRQS)
if (class->usage_mask & LOCKF_ENABLED_HARDIRQ)
nr_hardirq_unsafe++;
if (class->usage_mask & LOCKF_USED_IN_IRQ_READ)
nr_irq_read_safe++;
if (class->usage_mask & LOCKF_ENABLED_IRQS_READ)
if (class->usage_mask & LOCKF_ENABLED_IRQ_READ)
nr_irq_read_unsafe++;
if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ)
nr_softirq_read_safe++;
if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ_READ)
nr_softirq_read_unsafe++;
if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ)
nr_hardirq_read_safe++;
if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_READ)
nr_hardirq_read_unsafe++;
#ifdef CONFIG_PROVE_LOCKING
......@@ -601,6 +601,10 @@ static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
static void seq_header(struct seq_file *m)
{
seq_printf(m, "lock_stat version 0.3\n");
if (unlikely(!debug_locks))
seq_printf(m, "*WARNING* lock debugging disabled!! - possibly due to a lockdep warning\n");
seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s "
"%14s %14s\n",
......
/*
* Lockdep states,
*
* please update XXX_LOCK_USAGE_STATES in include/linux/lockdep.h whenever
* you add one, or come up with a nice dynamic solution.
*/
LOCKDEP_STATE(HARDIRQ)
LOCKDEP_STATE(SOFTIRQ)
LOCKDEP_STATE(RECLAIM_FS)
......@@ -26,11 +26,6 @@
/*
* Must be called with lock->wait_lock held.
*/
void debug_mutex_set_owner(struct mutex *lock, struct thread_info *new_owner)
{
lock->owner = new_owner;
}
void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
{
memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
......@@ -59,7 +54,6 @@ void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
/* Mark the current thread as blocked on the lock: */
ti->task->blocked_on = waiter;
waiter->lock = lock;
}
void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
......@@ -82,7 +76,7 @@ void debug_mutex_unlock(struct mutex *lock)
DEBUG_LOCKS_WARN_ON(lock->magic != lock);
DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
mutex_clear_owner(lock);
}
void debug_mutex_init(struct mutex *lock, const char *name,
......@@ -95,7 +89,6 @@ void debug_mutex_init(struct mutex *lock, const char *name,
debug_check_no_locks_freed((void *)lock, sizeof(*lock));
lockdep_init_map(&lock->dep_map, name, key, 0);
#endif
lock->owner = NULL;
lock->magic = lock;
}
......
......@@ -13,14 +13,6 @@
/*
* This must be called with lock->wait_lock held.
*/
extern void
debug_mutex_set_owner(struct mutex *lock, struct thread_info *new_owner);
static inline void debug_mutex_clear_owner(struct mutex *lock)
{
lock->owner = NULL;
}
extern void debug_mutex_lock_common(struct mutex *lock,
struct mutex_waiter *waiter);
extern void debug_mutex_wake_waiter(struct mutex *lock,
......@@ -35,6 +27,16 @@ extern void debug_mutex_unlock(struct mutex *lock);
extern void debug_mutex_init(struct mutex *lock, const char *name,
struct lock_class_key *key);
static inline void mutex_set_owner(struct mutex *lock)
{
lock->owner = current_thread_info();
}
static inline void mutex_clear_owner(struct mutex *lock)
{
lock->owner = NULL;
}
#define spin_lock_mutex(lock, flags) \
do { \
struct mutex *l = container_of(lock, struct mutex, wait_lock); \
......
......@@ -10,6 +10,11 @@
* Many thanks to Arjan van de Ven, Thomas Gleixner, Steven Rostedt and
* David Howells for suggestions and improvements.
*
* - Adaptive spinning for mutexes by Peter Zijlstra. (Ported to mainline
* from the -rt tree, where it was originally implemented for rtmutexes
* by Steven Rostedt, based on work by Gregory Haskins, Peter Morreale
* and Sven Dietrich.
*
* Also see Documentation/mutex-design.txt.
*/
#include <linux/mutex.h>
......@@ -46,6 +51,7 @@ __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key)
atomic_set(&lock->count, 1);
spin_lock_init(&lock->wait_lock);
INIT_LIST_HEAD(&lock->wait_list);
mutex_clear_owner(lock);
debug_mutex_init(lock, name, key);
}
......@@ -91,6 +97,7 @@ void inline __sched mutex_lock(struct mutex *lock)
* 'unlocked' into 'locked' state.
*/
__mutex_fastpath_lock(&lock->count, __mutex_lock_slowpath);
mutex_set_owner(lock);
}
EXPORT_SYMBOL(mutex_lock);
......@@ -115,6 +122,14 @@ void __sched mutex_unlock(struct mutex *lock)
* The unlocking fastpath is the 0->1 transition from 'locked'
* into 'unlocked' state:
*/
#ifndef CONFIG_DEBUG_MUTEXES
/*
* When debugging is enabled we must not clear the owner before time,