Commit ec0a7d44 authored by Matthew Brost's avatar Matthew Brost Committed by Tejun Heo
Browse files

workqueue: Add interface for user-defined workqueue lockdep map 



Add an interface for a user-defined workqueue lockdep map, which is
helpful when multiple workqueues are created for the same purpose. This
also helps avoid leaking lockdep maps on each workqueue creation.

v2:
 - Add alloc_workqueue_lockdep_map (Tejun)
v3:
 - Drop __WQ_USER_OWNED_LOCKDEP (Tejun)
 - static inline alloc_ordered_workqueue_lockdep_map (Tejun)

Cc: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: default avatarMatthew Brost <matthew.brost@intel.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 4f022f43

include/linux/workqueue.h

+52 −0
Original line number Diff line number Diff line
@@ -507,6 +507,58 @@ void workqueue_softirq_dead(unsigned int cpu); 
__printf(1, 4) struct workqueue_struct *

alloc_workqueue(const char *fmt, unsigned int flags, int max_active, ...);



#ifdef CONFIG_LOCKDEP

/**

 * alloc_workqueue_lockdep_map - allocate a workqueue with user-defined lockdep_map

 * @fmt: printf format for the name of the workqueue

 * @flags: WQ_* flags

 * @max_active: max in-flight work items, 0 for default

 * @lockdep_map: user-defined lockdep_map

 * @...: args for @fmt

 *

 * Same as alloc_workqueue but with the a user-define lockdep_map. Useful for

 * workqueues created with the same purpose and to avoid leaking a lockdep_map

 * on each workqueue creation.

 *

 * RETURNS:

 * Pointer to the allocated workqueue on success, %NULL on failure.

 */

__printf(1, 5) struct workqueue_struct *

alloc_workqueue_lockdep_map(const char *fmt, unsigned int flags, int max_active,

			    struct lockdep_map *lockdep_map, ...);



/**

 * alloc_ordered_workqueue_lockdep_map - allocate an ordered workqueue with

 * user-defined lockdep_map

 *

 * @fmt: printf format for the name of the workqueue

 * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)

 * @lockdep_map: user-defined lockdep_map

 * @args: args for @fmt

 *

 * Same as alloc_ordered_workqueue but with the a user-define lockdep_map.

 * Useful for workqueues created with the same purpose and to avoid leaking a

 * lockdep_map on each workqueue creation.

 *

 * RETURNS:

 * Pointer to the allocated workqueue on success, %NULL on failure.

 */

__printf(1, 4) static inline struct workqueue_struct *

alloc_ordered_workqueue_lockdep_map(const char *fmt, unsigned int flags,

				    struct lockdep_map *lockdep_map, ...)

{

	struct workqueue_struct *wq;

	va_list args;



	va_start(args, lockdep_map);

	wq = alloc_workqueue_lockdep_map(fmt, WQ_UNBOUND | __WQ_ORDERED | flags,

					 1, lockdep_map, args);

	va_end(args);



	return wq;

}

#endif



/**

 * alloc_ordered_workqueue - allocate an ordered workqueue

 * @fmt: printf format for the name of the workqueue

kernel/workqueue.c

+28 −0
Original line number Diff line number Diff line
@@ -4775,11 +4775,17 @@ static void wq_init_lockdep(struct workqueue_struct *wq) 


static void wq_unregister_lockdep(struct workqueue_struct *wq)

{

	if (wq->lockdep_map != &wq->__lockdep_map)

		return;



	lockdep_unregister_key(&wq->key);

}



static void wq_free_lockdep(struct workqueue_struct *wq)

{

	if (wq->lockdep_map != &wq->__lockdep_map)

		return;



	if (wq->lock_name != wq->name)

		kfree(wq->lock_name);

}
@@ -5756,6 +5762,28 @@ struct workqueue_struct *alloc_workqueue(const char *fmt, 
}

EXPORT_SYMBOL_GPL(alloc_workqueue);



#ifdef CONFIG_LOCKDEP

__printf(1, 5)

struct workqueue_struct *

alloc_workqueue_lockdep_map(const char *fmt, unsigned int flags,

			    int max_active, struct lockdep_map *lockdep_map, ...)

{

	struct workqueue_struct *wq;

	va_list args;



	va_start(args, lockdep_map);

	wq = __alloc_workqueue(fmt, flags, max_active, args);

	va_end(args);

	if (!wq)

		return NULL;



	wq->lockdep_map = lockdep_map;



	return wq;

}

EXPORT_SYMBOL_GPL(alloc_workqueue_lockdep_map);

#endif



static bool pwq_busy(struct pool_workqueue *pwq)

{

	int i;