Commit 866b8870 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'wq-for-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 

Pull workqueue update from Tejun Heo:
 "Just one commit to improve lockdep annotation for work_on_cpu() to
  avoid spurious warnings"

* tag 'wq-for-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: Provide one lock class key per work_on_cpu() callsite
parents 639409a4 265f3ed0

include/linux/workqueue.h

+39 −7
Original line number Diff line number Diff line
@@ -274,18 +274,16 @@ static inline unsigned int work_static(struct work_struct *work) { return 0; } 
 * to generate better code.

 */

#ifdef CONFIG_LOCKDEP

#define __INIT_WORK(_work, _func, _onstack)				\

#define __INIT_WORK_KEY(_work, _func, _onstack, _key)			\

	do {								\

		static struct lock_class_key __key;			\

									\

		__init_work((_work), _onstack);				\

		(_work)->data = (atomic_long_t) WORK_DATA_INIT();	\

		lockdep_init_map(&(_work)->lockdep_map, "(work_completion)"#_work, &__key, 0); \

		lockdep_init_map(&(_work)->lockdep_map, "(work_completion)"#_work, (_key), 0); \

		INIT_LIST_HEAD(&(_work)->entry);			\

		(_work)->func = (_func);				\

	} while (0)

#else

#define __INIT_WORK(_work, _func, _onstack)				\

#define __INIT_WORK_KEY(_work, _func, _onstack, _key)			\

	do {								\

		__init_work((_work), _onstack);				\

		(_work)->data = (atomic_long_t) WORK_DATA_INIT();	\
@@ -294,12 +292,22 @@ static inline unsigned int work_static(struct work_struct *work) { return 0; } 
	} while (0)

#endif



#define __INIT_WORK(_work, _func, _onstack)				\

	do {								\

		static __maybe_unused struct lock_class_key __key;	\

									\

		__INIT_WORK_KEY(_work, _func, _onstack, &__key);	\

	} while (0)



#define INIT_WORK(_work, _func)						\

	__INIT_WORK((_work), (_func), 0)



#define INIT_WORK_ONSTACK(_work, _func)					\

	__INIT_WORK((_work), (_func), 1)



#define INIT_WORK_ONSTACK_KEY(_work, _func, _key)			\

	__INIT_WORK_KEY((_work), (_func), 1, _key)



#define __INIT_DELAYED_WORK(_work, _func, _tflags)			\

	do {								\

		INIT_WORK(&(_work)->work, (_func));			\
@@ -693,8 +701,32 @@ static inline long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg) 
	return fn(arg);

}

#else

long work_on_cpu(int cpu, long (*fn)(void *), void *arg);

long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg);

long work_on_cpu_key(int cpu, long (*fn)(void *),

		     void *arg, struct lock_class_key *key);

/*

 * A new key is defined for each caller to make sure the work

 * associated with the function doesn't share its locking class.

 */

#define work_on_cpu(_cpu, _fn, _arg)			\

({							\

	static struct lock_class_key __key;		\

							\

	work_on_cpu_key(_cpu, _fn, _arg, &__key);	\

})



long work_on_cpu_safe_key(int cpu, long (*fn)(void *),

			  void *arg, struct lock_class_key *key);



/*

 * A new key is defined for each caller to make sure the work

 * associated with the function doesn't share its locking class.

 */

#define work_on_cpu_safe(_cpu, _fn, _arg)		\

({							\

	static struct lock_class_key __key;		\

							\

	work_on_cpu_safe_key(_cpu, _fn, _arg, &__key);	\

})

#endif /* CONFIG_SMP */



#ifdef CONFIG_FREEZER

kernel/workqueue.c

+12 −8
Original line number Diff line number Diff line
@@ -5622,50 +5622,54 @@ static void work_for_cpu_fn(struct work_struct *work) 
}



/**

 * work_on_cpu - run a function in thread context on a particular cpu

 * work_on_cpu_key - run a function in thread context on a particular cpu

 * @cpu: the cpu to run on

 * @fn: the function to run

 * @arg: the function arg

 * @key: The lock class key for lock debugging purposes

 *

 * It is up to the caller to ensure that the cpu doesn't go offline.

 * The caller must not hold any locks which would prevent @fn from completing.

 *

 * Return: The value @fn returns.

 */

long work_on_cpu(int cpu, long (*fn)(void *), void *arg)

long work_on_cpu_key(int cpu, long (*fn)(void *),

		     void *arg, struct lock_class_key *key)

{

	struct work_for_cpu wfc = { .fn = fn, .arg = arg };



	INIT_WORK_ONSTACK(&wfc.work, work_for_cpu_fn);

	INIT_WORK_ONSTACK_KEY(&wfc.work, work_for_cpu_fn, key);

	schedule_work_on(cpu, &wfc.work);

	flush_work(&wfc.work);

	destroy_work_on_stack(&wfc.work);

	return wfc.ret;

}

EXPORT_SYMBOL_GPL(work_on_cpu);

EXPORT_SYMBOL_GPL(work_on_cpu_key);



/**

 * work_on_cpu_safe - run a function in thread context on a particular cpu

 * work_on_cpu_safe_key - run a function in thread context on a particular cpu

 * @cpu: the cpu to run on

 * @fn:  the function to run

 * @arg: the function argument

 * @key: The lock class key for lock debugging purposes

 *

 * Disables CPU hotplug and calls work_on_cpu(). The caller must not hold

 * any locks which would prevent @fn from completing.

 *

 * Return: The value @fn returns.

 */

long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg)

long work_on_cpu_safe_key(int cpu, long (*fn)(void *),

			  void *arg, struct lock_class_key *key)

{

	long ret = -ENODEV;



	cpus_read_lock();

	if (cpu_online(cpu))

		ret = work_on_cpu(cpu, fn, arg);

		ret = work_on_cpu_key(cpu, fn, arg, key);

	cpus_read_unlock();

	return ret;

}

EXPORT_SYMBOL_GPL(work_on_cpu_safe);

EXPORT_SYMBOL_GPL(work_on_cpu_safe_key);

#endif /* CONFIG_SMP */



#ifdef CONFIG_FREEZER