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)

Matthew Brost committed 2 years ago

Commit ec0a7d41 parent 4f022f42 files · +80 −0Browse files

Unified · Split

2 files

include/linux/workqueue.h +52 −0
kernel/workqueue.c +28 −0

include/linux/workqueue.h+52−0

@@ -507,6 +507,58 @@ void workqueue_softirq_dead(unsigned int cpu); · 506 unmodified lines
507	507	__printf(1, 4) struct workqueue_struct *
508	508	alloc_workqueue(const char *fmt, unsigned int flags, int max_active, ...);
509	509
	510	+#ifdef CONFIG_LOCKDEP
	511	+/**
	512	+ * alloc_workqueue_lockdep_map - allocate a workqueue with user-defined lockdep_map
	513	+ * @fmt: printf format for the name of the workqueue
	514	+ * @flags: WQ_* flags
	515	+ * @max_active: max in-flight work items, 0 for default
	516	+ * @lockdep_map: user-defined lockdep_map
	517	+ * @...: args for @fmt
	518	+ *
	519	+ * Same as alloc_workqueue but with the a user-define lockdep_map. Useful for
	520	+ * workqueues created with the same purpose and to avoid leaking a lockdep_map
	521	+ * on each workqueue creation.
	522	+ *
	523	+ * RETURNS:
	524	+ * Pointer to the allocated workqueue on success, %NULL on failure.
	525	+ */
	526	+__printf(1, 5) struct workqueue_struct *
	527	+alloc_workqueue_lockdep_map(const char *fmt, unsigned int flags, int max_active,
	528	+ struct lockdep_map *lockdep_map, ...);
	529	+
	530	+/**
	531	+ * alloc_ordered_workqueue_lockdep_map - allocate an ordered workqueue with
	532	+ * user-defined lockdep_map
	533	+ *
	534	+ * @fmt: printf format for the name of the workqueue
	535	+ * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
	536	+ * @lockdep_map: user-defined lockdep_map
	537	+ * @args: args for @fmt
	538	+ *
	539	+ * Same as alloc_ordered_workqueue but with the a user-define lockdep_map.
	540	+ * Useful for workqueues created with the same purpose and to avoid leaking a
	541	+ * lockdep_map on each workqueue creation.
	542	+ *
	543	+ * RETURNS:
	544	+ * Pointer to the allocated workqueue on success, %NULL on failure.
	545	+ */
	546	+__printf(1, 4) static inline struct workqueue_struct *
	547	+alloc_ordered_workqueue_lockdep_map(const char *fmt, unsigned int flags,
	548	+ struct lockdep_map *lockdep_map, ...)
	549	+{
	550	+ struct workqueue_struct *wq;
	551	+ va_list args;
	552	+
	553	+ va_start(args, lockdep_map);
	554	+ wq = alloc_workqueue_lockdep_map(fmt, WQ_UNBOUND \| __WQ_ORDERED \| flags,
	555	+ 1, lockdep_map, args);
	556	+ va_end(args);
	557	+
	558	+ return wq;
	559	+}
	560	+#endif
	561	+
510	562	/**
511	563	* alloc_ordered_workqueue - allocate an ordered workqueue
512	564	* @fmt: printf format for the name of the workqueue

kernel/workqueue.c+28−0

@@ -4775,11 +4775,17 @@ static void wq_init_lockdep(struct workqueue_struct *wq) · 4774 unmodified lines
4775	4775
4776	4776	static void wq_unregister_lockdep(struct workqueue_struct *wq)
4777	4777	{
	4778	+ if (wq->lockdep_map != &wq->__lockdep_map)
	4779	+ return;
	4780	+
4778	4781	lockdep_unregister_key(&wq->key);
4779	4782	}
4780	4783
4781	4784	static void wq_free_lockdep(struct workqueue_struct *wq)
4782	4785	{
	4786	+ if (wq->lockdep_map != &wq->__lockdep_map)
	4787	+ return;
	4788	+
4783	4789	if (wq->lock_name != wq->name)
4784	4790	kfree(wq->lock_name);
4785	4791	}
@@ -5756,6 +5762,28 @@ struct workqueue_struct alloc_workqueue(const char fmt, · 970 unmodified lines
5756	5762	}
5757	5763	EXPORT_SYMBOL_GPL(alloc_workqueue);
5758	5764
	5765	+#ifdef CONFIG_LOCKDEP
	5766	+__printf(1, 5)
	5767	+struct workqueue_struct *
	5768	+alloc_workqueue_lockdep_map(const char *fmt, unsigned int flags,
	5769	+ int max_active, struct lockdep_map *lockdep_map, ...)
	5770	+{
	5771	+ struct workqueue_struct *wq;
	5772	+ va_list args;
	5773	+
	5774	+ va_start(args, lockdep_map);
	5775	+ wq = __alloc_workqueue(fmt, flags, max_active, args);
	5776	+ va_end(args);
	5777	+ if (!wq)
	5778	+ return NULL;
	5779	+
	5780	+ wq->lockdep_map = lockdep_map;
	5781	+
	5782	+ return wq;
	5783	+}
	5784	+EXPORT_SYMBOL_GPL(alloc_workqueue_lockdep_map);
	5785	+#endif
	5786	+
5759	5787	static bool pwq_busy(struct pool_workqueue *pwq)
5760	5788	{
5761	5789	int i;