#define __LINUX_LOCKDEP_H
struct task_struct;
+struct lockdep_map;
#ifdef CONFIG_LOCKDEP
const char *name;
int name_version;
+
+#ifdef CONFIG_LOCK_STAT
+ unsigned long contention_point[4];
+#endif
+};
+
+#ifdef CONFIG_LOCK_STAT
+struct lock_time {
+ s64 min;
+ s64 max;
+ s64 total;
+ unsigned long nr;
};
+struct lock_class_stats {
+ unsigned long contention_point[4];
+ struct lock_time read_waittime;
+ struct lock_time write_waittime;
+ struct lock_time read_holdtime;
+ struct lock_time write_holdtime;
+};
+
+struct lock_class_stats lock_stats(struct lock_class *class);
+void clear_lock_stats(struct lock_class *class);
+#endif
+
/*
* Map the lock object (the lock instance) to the lock-class object.
* This is embedded into specific lock instances:
unsigned long acquire_ip;
struct lockdep_map *instance;
+#ifdef CONFIG_LOCK_STAT
+ u64 waittime_stamp;
+ u64 holdtime_stamp;
+#endif
/*
* The lock-stack is unified in that the lock chains of interrupt
* contexts nest ontop of process context chains, but we 'separate'
#endif /* !LOCKDEP */
+#ifdef CONFIG_LOCK_STAT
+
+extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
+extern void lock_acquired(struct lockdep_map *lock);
+
+#define LOCK_CONTENDED(_lock, try, lock) \
+do { \
+ if (!try(_lock)) { \
+ lock_contended(&(_lock)->dep_map, _RET_IP_); \
+ lock(_lock); \
+ lock_acquired(&(_lock)->dep_map); \
+ } \
+} while (0)
+
+#else /* CONFIG_LOCK_STAT */
+
+#define lock_contended(lockdep_map, ip) do {} while (0)
+#define lock_acquired(lockdep_map) do {} while (0)
+
+#define LOCK_CONTENDED(_lock, try, lock) \
+ lock(_lock)
+
+#endif /* CONFIG_LOCK_STAT */
+
#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_GENERIC_HARDIRQS)
extern void early_init_irq_lock_class(void);
#else
#include "lockdep_internals.h"
+#ifdef CONFIG_PROVE_LOCKING
+int prove_locking = 1;
+module_param(prove_locking, int, 0644);
+#else
+#define prove_locking 0
+#endif
+
+#ifdef CONFIG_LOCK_STAT
+int lock_stat = 1;
+module_param(lock_stat, int, 0644);
+#else
+#define lock_stat 0
+#endif
+
/*
* lockdep_lock: protects the lockdep graph, the hashes and the
* class/list/hash allocators.
unsigned long nr_lock_classes;
static struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
+#ifdef CONFIG_LOCK_STAT
+static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], lock_stats);
+
+static int lock_contention_point(struct lock_class *class, unsigned long ip)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(class->contention_point); i++) {
+ if (class->contention_point[i] == 0) {
+ class->contention_point[i] = ip;
+ break;
+ }
+ if (class->contention_point[i] == ip)
+ break;
+ }
+
+ return i;
+}
+
+static void lock_time_inc(struct lock_time *lt, s64 time)
+{
+ if (time > lt->max)
+ lt->max = time;
+
+ if (time < lt->min || !lt->min)
+ lt->min = time;
+
+ lt->total += time;
+ lt->nr++;
+}
+
+static struct lock_class_stats *get_lock_stats(struct lock_class *class)
+{
+ return &get_cpu_var(lock_stats)[class - lock_classes];
+}
+
+static void put_lock_stats(struct lock_class_stats *stats)
+{
+ put_cpu_var(lock_stats);
+}
+
+static void lock_release_holdtime(struct held_lock *hlock)
+{
+ struct lock_class_stats *stats;
+ s64 holdtime;
+
+ if (!lock_stat)
+ return;
+
+ holdtime = sched_clock() - hlock->holdtime_stamp;
+
+ stats = get_lock_stats(hlock->class);
+ if (hlock->read)
+ lock_time_inc(&stats->read_holdtime, holdtime);
+ else
+ lock_time_inc(&stats->write_holdtime, holdtime);
+ put_lock_stats(stats);
+}
+#else
+static inline void lock_release_holdtime(struct held_lock *hlock)
+{
+}
+#endif
+
/*
* We keep a global list of all lock classes. The list only grows,
* never shrinks. The list is only accessed with the lockdep
int chain_head = 0;
u64 chain_key;
+ if (!prove_locking)
+ check = 1;
+
if (unlikely(!debug_locks))
return 0;
hlock->read = read;
hlock->check = check;
hlock->hardirqs_off = hardirqs_off;
+#ifdef CONFIG_LOCK_STAT
+ hlock->waittime_stamp = 0;
+ hlock->holdtime_stamp = sched_clock();
+#endif
if (check == 2 && !mark_irqflags(curr, hlock))
return 0;
return print_unlock_inbalance_bug(curr, lock, ip);
found_it:
+ lock_release_holdtime(hlock);
+
/*
* We have the right lock to unlock, 'hlock' points to it.
* Now we remove it from the stack, and add back the other
curr->curr_chain_key = hlock->prev_chain_key;
+ lock_release_holdtime(hlock);
+
#ifdef CONFIG_DEBUG_LOCKDEP
hlock->prev_chain_key = 0;
hlock->class = NULL;
{
unsigned long flags;
+ if (unlikely(!lock_stat && !prove_locking))
+ return;
+
if (unlikely(current->lockdep_recursion))
return;
{
unsigned long flags;
+ if (unlikely(!lock_stat && !prove_locking))
+ return;
+
if (unlikely(current->lockdep_recursion))
return;
EXPORT_SYMBOL_GPL(lock_release);
+#ifdef CONFIG_LOCK_STAT
+static int
+print_lock_contention_bug(struct task_struct *curr, struct lockdep_map *lock,
+ unsigned long ip)
+{
+ if (!debug_locks_off())
+ return 0;
+ if (debug_locks_silent)
+ return 0;
+
+ printk("\n=================================\n");
+ printk( "[ BUG: bad contention detected! ]\n");
+ printk( "---------------------------------\n");
+ printk("%s/%d is trying to contend lock (",
+ curr->comm, curr->pid);
+ print_lockdep_cache(lock);
+ printk(") at:\n");
+ print_ip_sym(ip);
+ printk("but there are no locks held!\n");
+ printk("\nother info that might help us debug this:\n");
+ lockdep_print_held_locks(curr);
+
+ printk("\nstack backtrace:\n");
+ dump_stack();
+
+ return 0;
+}
+
+static void
+__lock_contended(struct lockdep_map *lock, unsigned long ip)
+{
+ struct task_struct *curr = current;
+ struct held_lock *hlock, *prev_hlock;
+ struct lock_class_stats *stats;
+ unsigned int depth;
+ int i, point;
+
+ depth = curr->lockdep_depth;
+ if (DEBUG_LOCKS_WARN_ON(!depth))
+ return;
+
+ prev_hlock = NULL;
+ for (i = depth-1; i >= 0; i--) {
+ hlock = curr->held_locks + i;
+ /*
+ * We must not cross into another context:
+ */
+ if (prev_hlock && prev_hlock->irq_context != hlock->irq_context)
+ break;
+ if (hlock->instance == lock)
+ goto found_it;
+ prev_hlock = hlock;
+ }
+ print_lock_contention_bug(curr, lock, ip);
+ return;
+
+found_it:
+ hlock->waittime_stamp = sched_clock();
+
+ point = lock_contention_point(hlock->class, ip);
+
+ stats = get_lock_stats(hlock->class);
+ if (point < ARRAY_SIZE(stats->contention_point))
+ stats->contention_point[i]++;
+ put_lock_stats(stats);
+}
+
+static void
+__lock_acquired(struct lockdep_map *lock)
+{
+ struct task_struct *curr = current;
+ struct held_lock *hlock, *prev_hlock;
+ struct lock_class_stats *stats;
+ unsigned int depth;
+ u64 now;
+ s64 waittime;
+ int i;
+
+ depth = curr->lockdep_depth;
+ if (DEBUG_LOCKS_WARN_ON(!depth))
+ return;
+
+ prev_hlock = NULL;
+ for (i = depth-1; i >= 0; i--) {
+ hlock = curr->held_locks + i;
+ /*
+ * We must not cross into another context:
+ */
+ if (prev_hlock && prev_hlock->irq_context != hlock->irq_context)
+ break;
+ if (hlock->instance == lock)
+ goto found_it;
+ prev_hlock = hlock;
+ }
+ print_lock_contention_bug(curr, lock, _RET_IP_);
+ return;
+
+found_it:
+ if (!hlock->waittime_stamp)
+ return;
+
+ now = sched_clock();
+ waittime = now - hlock->waittime_stamp;
+ hlock->holdtime_stamp = now;
+
+ stats = get_lock_stats(hlock->class);
+ if (hlock->read)
+ lock_time_inc(&stats->read_waittime, waittime);
+ else
+ lock_time_inc(&stats->write_waittime, waittime);
+ put_lock_stats(stats);
+}
+
+void lock_contended(struct lockdep_map *lock, unsigned long ip)
+{
+ unsigned long flags;
+
+ if (unlikely(!lock_stat))
+ return;
+
+ if (unlikely(current->lockdep_recursion))
+ return;
+
+ raw_local_irq_save(flags);
+ check_flags(flags);
+ current->lockdep_recursion = 1;
+ __lock_contended(lock, ip);
+ current->lockdep_recursion = 0;
+ raw_local_irq_restore(flags);
+}
+EXPORT_SYMBOL_GPL(lock_contended);
+
+void lock_acquired(struct lockdep_map *lock)
+{
+ unsigned long flags;
+
+ if (unlikely(!lock_stat))
+ return;
+
+ if (unlikely(current->lockdep_recursion))
+ return;
+
+ raw_local_irq_save(flags);
+ check_flags(flags);
+ current->lockdep_recursion = 1;
+ __lock_acquired(lock);
+ current->lockdep_recursion = 0;
+ raw_local_irq_restore(flags);
+}
+EXPORT_SYMBOL_GPL(lock_acquired);
+#endif
+
/*
* Used by the testsuite, sanitize the validator state
* after a simulated failure:
projects / linux-2.6 / commitdiff