Show the counter and the owner of the lock when dumping held locks in the system.
This is useful to figure out who really holds a lock and how many waiters it has. Signed-off-by: Sasha Levin <[email protected]> --- drivers/usb/storage/usb.c | 2 +- fs/inode.c | 3 ++- fs/super.c | 3 ++- include/linux/lockdep.h | 2 +- include/linux/mutex-debug.h | 2 ++ include/linux/mutex.h | 2 +- kernel/events/core.c | 3 ++- kernel/locking/lockdep.c | 8 +++++++- kernel/locking/mutex-debug.c | 14 +++++++++++++- 9 files changed, 31 insertions(+), 8 deletions(-) diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c index d468d02..b0a2565 100644 --- a/drivers/usb/storage/usb.c +++ b/drivers/usb/storage/usb.c @@ -165,7 +165,7 @@ static void us_set_lock_class(struct mutex *mutex, BUG_ON(i == config->desc.bNumInterfaces); - lockdep_set_class(mutex, &us_interface_key[i]); + lockdep_set_class_type(mutex, &us_interface_key[i], LOCKTYPE_MUTEX); } #else diff --git a/fs/inode.c b/fs/inode.c index 3a53b1d..8e24ff7 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -160,7 +160,8 @@ int inode_init_always(struct super_block *sb, struct inode *inode) lockdep_set_class(&inode->i_lock, &sb->s_type->i_lock_key); mutex_init(&inode->i_mutex); - lockdep_set_class(&inode->i_mutex, &sb->s_type->i_mutex_key); + lockdep_set_class_type(&inode->i_mutex, &sb->s_type->i_mutex_key, + LOCKTYPE_MUTEX); atomic_set(&inode->i_dio_count, 0); diff --git a/fs/super.c b/fs/super.c index eae088f..d6b585c 100644 --- a/fs/super.c +++ b/fs/super.c @@ -217,7 +217,8 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags) s->s_count = 1; atomic_set(&s->s_active, 1); mutex_init(&s->s_vfs_rename_mutex); - lockdep_set_class(&s->s_vfs_rename_mutex, &type->s_vfs_rename_key); + lockdep_set_class_type(&s->s_vfs_rename_mutex, + &type->s_vfs_rename_key, LOCKTYPE_MUTEX); mutex_init(&s->s_dquot.dqio_mutex); mutex_init(&s->s_dquot.dqonoff_mutex); s->s_maxbytes = MAX_NON_LFS; diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 2f4c3fe..cab929b 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -143,7 +143,7 @@ struct lock_class_stats lock_stats(struct lock_class *class); void clear_lock_stats(struct lock_class *class); #endif -enum LOCK_TYPE { LOCKTYPE_NONE, }; +enum LOCK_TYPE { LOCKTYPE_NONE, LOCKTYPE_MUTEX, }; /* * Map the lock object (the lock instance) to the lock-class object. diff --git a/include/linux/mutex-debug.h b/include/linux/mutex-debug.h index 4ac8b19..ed125d3 100644 --- a/include/linux/mutex-debug.h +++ b/include/linux/mutex-debug.h @@ -21,4 +21,6 @@ do { \ extern void mutex_destroy(struct mutex *lock); +extern void mutex_print_debug(const struct mutex *lock); + #endif diff --git a/include/linux/mutex.h b/include/linux/mutex.h index cc31498..cba876d 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -102,7 +102,7 @@ static inline void mutex_destroy(struct mutex *lock) {} #ifdef CONFIG_DEBUG_LOCK_ALLOC # define __DEP_MAP_MUTEX_INITIALIZER(lockname) \ - , .dep_map = { .name = #lockname } + , .dep_map = { .name = #lockname, .type = LOCKTYPE_MUTEX } #else # define __DEP_MAP_MUTEX_INITIALIZER(lockname) #endif diff --git a/kernel/events/core.c b/kernel/events/core.c index 4c1ee7f..fef4343 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6777,7 +6777,8 @@ skip_type: cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); __perf_event_init_context(&cpuctx->ctx); - lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); + lockdep_set_class_type(&cpuctx->ctx.mutex, &cpuctx_mutex, + LOCKTYPE_MUTEX); lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); cpuctx->ctx.type = cpu_context; cpuctx->ctx.pmu = pmu; diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index de4c9aa..07c337d 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -510,8 +510,14 @@ void get_usage_chars(struct lock_class *class, char usage[LOCK_USAGE_CHARS]) static void get_lock_info(enum LOCK_TYPE t, struct lockdep_map *map) { + struct mutex *mtx; + switch (t) { - case LOCKTYPE_NONE: return; + case LOCKTYPE_NONE: break; + case LOCKTYPE_MUTEX: + mtx = container_of(map, struct mutex, dep_map); + mutex_print_debug(mtx); + break; } } diff --git a/kernel/locking/mutex-debug.c b/kernel/locking/mutex-debug.c index 5cf6731..e97f763 100644 --- a/kernel/locking/mutex-debug.c +++ b/kernel/locking/mutex-debug.c @@ -98,7 +98,7 @@ void debug_mutex_init(struct mutex *lock, const char *name, * Make sure we are not reinitializing a held lock: */ debug_check_no_locks_freed((void *)lock, sizeof(*lock)); - lockdep_init_map(&lock->dep_map, name, key, 0); + lockdep_init_map_type(&lock->dep_map, name, key, 0, LOCKTYPE_MUTEX); #endif lock->magic = lock; } @@ -118,3 +118,15 @@ void mutex_destroy(struct mutex *lock) } EXPORT_SYMBOL_GPL(mutex_destroy); + +void mutex_print_debug(const struct mutex *lock) +{ + const char *owner = "None"; + int c = atomic_read(&lock->count); + + if (lock->owner) + owner = lock->owner->comm; + + printk("Mutex: counter: %d owner: %s\n", c, owner); +} +EXPORT_SYMBOL_GPL(mutex_print_debug); -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
