2 * workqueue.h --- work queue handling for Linux.
5 #ifndef _LINUX_WORKQUEUE_H
6 #define _LINUX_WORKQUEUE_H
8 #include <linux/timer.h>
9 #include <linux/linkage.h>
10 #include <linux/bitops.h>
11 #include <linux/lockdep.h>
12 #include <linux/threads.h>
13 #include <asm/atomic.h>
15 struct workqueue_struct
;
18 typedef void (*work_func_t
)(struct work_struct
*work
);
21 * The first word is the work queue pointer and the flags rolled into
24 #define work_data_bits(work) ((unsigned long *)(&(work)->data))
27 WORK_STRUCT_PENDING_BIT
= 0, /* work item is pending execution */
28 WORK_STRUCT_DELAYED_BIT
= 1, /* work item is delayed */
29 WORK_STRUCT_CWQ_BIT
= 2, /* data points to cwq */
30 WORK_STRUCT_LINKED_BIT
= 3, /* next work is linked to this one */
31 #ifdef CONFIG_DEBUG_OBJECTS_WORK
32 WORK_STRUCT_STATIC_BIT
= 4, /* static initializer (debugobjects) */
33 WORK_STRUCT_COLOR_SHIFT
= 5, /* color for workqueue flushing */
35 WORK_STRUCT_COLOR_SHIFT
= 4, /* color for workqueue flushing */
38 WORK_STRUCT_COLOR_BITS
= 4,
40 WORK_STRUCT_PENDING
= 1 << WORK_STRUCT_PENDING_BIT
,
41 WORK_STRUCT_DELAYED
= 1 << WORK_STRUCT_DELAYED_BIT
,
42 WORK_STRUCT_CWQ
= 1 << WORK_STRUCT_CWQ_BIT
,
43 WORK_STRUCT_LINKED
= 1 << WORK_STRUCT_LINKED_BIT
,
44 #ifdef CONFIG_DEBUG_OBJECTS_WORK
45 WORK_STRUCT_STATIC
= 1 << WORK_STRUCT_STATIC_BIT
,
47 WORK_STRUCT_STATIC
= 0,
51 * The last color is no color used for works which don't
52 * participate in workqueue flushing.
54 WORK_NR_COLORS
= (1 << WORK_STRUCT_COLOR_BITS
) - 1,
55 WORK_NO_COLOR
= WORK_NR_COLORS
,
58 WORK_CPU_UNBOUND
= NR_CPUS
,
59 WORK_CPU_NONE
= NR_CPUS
+ 1,
60 WORK_CPU_LAST
= WORK_CPU_NONE
,
63 * Reserve 7 bits off of cwq pointer w/ debugobjects turned
64 * off. This makes cwqs aligned to 256 bytes and allows 15
65 * workqueue flush colors.
67 WORK_STRUCT_FLAG_BITS
= WORK_STRUCT_COLOR_SHIFT
+
68 WORK_STRUCT_COLOR_BITS
,
70 WORK_STRUCT_FLAG_MASK
= (1UL << WORK_STRUCT_FLAG_BITS
) - 1,
71 WORK_STRUCT_WQ_DATA_MASK
= ~WORK_STRUCT_FLAG_MASK
,
72 WORK_STRUCT_NO_CPU
= WORK_CPU_NONE
<< WORK_STRUCT_FLAG_BITS
,
74 /* bit mask for work_busy() return values */
75 WORK_BUSY_PENDING
= 1 << 0,
76 WORK_BUSY_RUNNING
= 1 << 1,
81 struct list_head entry
;
84 struct lockdep_map lockdep_map
;
88 #define WORK_DATA_INIT() ATOMIC_LONG_INIT(WORK_STRUCT_NO_CPU)
89 #define WORK_DATA_STATIC_INIT() \
90 ATOMIC_LONG_INIT(WORK_STRUCT_NO_CPU | WORK_STRUCT_STATIC)
93 struct work_struct work
;
94 struct timer_list timer
;
97 static inline struct delayed_work
*to_delayed_work(struct work_struct
*work
)
99 return container_of(work
, struct delayed_work
, work
);
102 struct execute_work
{
103 struct work_struct work
;
106 #ifdef CONFIG_LOCKDEP
108 * NB: because we have to copy the lockdep_map, setting _key
109 * here is required, otherwise it could get initialised to the
110 * copy of the lockdep_map!
112 #define __WORK_INIT_LOCKDEP_MAP(n, k) \
113 .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
115 #define __WORK_INIT_LOCKDEP_MAP(n, k)
118 #define __WORK_INITIALIZER(n, f) { \
119 .data = WORK_DATA_STATIC_INIT(), \
120 .entry = { &(n).entry, &(n).entry }, \
122 __WORK_INIT_LOCKDEP_MAP(#n, &(n)) \
125 #define __DELAYED_WORK_INITIALIZER(n, f) { \
126 .work = __WORK_INITIALIZER((n).work, (f)), \
127 .timer = TIMER_INITIALIZER(NULL, 0, 0), \
130 #define __DEFERRED_WORK_INITIALIZER(n, f) { \
131 .work = __WORK_INITIALIZER((n).work, (f)), \
132 .timer = TIMER_DEFERRED_INITIALIZER(NULL, 0, 0), \
135 #define DECLARE_WORK(n, f) \
136 struct work_struct n = __WORK_INITIALIZER(n, f)
138 #define DECLARE_DELAYED_WORK(n, f) \
139 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f)
141 #define DECLARE_DEFERRED_WORK(n, f) \
142 struct delayed_work n = __DEFERRED_WORK_INITIALIZER(n, f)
145 * initialize a work item's function pointer
147 #define PREPARE_WORK(_work, _func) \
149 (_work)->func = (_func); \
152 #define PREPARE_DELAYED_WORK(_work, _func) \
153 PREPARE_WORK(&(_work)->work, (_func))
155 #ifdef CONFIG_DEBUG_OBJECTS_WORK
156 extern void __init_work(struct work_struct
*work
, int onstack
);
157 extern void destroy_work_on_stack(struct work_struct
*work
);
158 static inline unsigned int work_static(struct work_struct
*work
)
160 return *work_data_bits(work
) & WORK_STRUCT_STATIC
;
163 static inline void __init_work(struct work_struct
*work
, int onstack
) { }
164 static inline void destroy_work_on_stack(struct work_struct
*work
) { }
165 static inline unsigned int work_static(struct work_struct
*work
) { return 0; }
169 * initialize all of a work item in one go
171 * NOTE! No point in using "atomic_long_set()": using a direct
172 * assignment of the work data initializer allows the compiler
173 * to generate better code.
175 #ifdef CONFIG_LOCKDEP
176 #define __INIT_WORK(_work, _func, _onstack) \
178 static struct lock_class_key __key; \
180 __init_work((_work), _onstack); \
181 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
182 lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0);\
183 INIT_LIST_HEAD(&(_work)->entry); \
184 PREPARE_WORK((_work), (_func)); \
187 #define __INIT_WORK(_work, _func, _onstack) \
189 __init_work((_work), _onstack); \
190 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
191 INIT_LIST_HEAD(&(_work)->entry); \
192 PREPARE_WORK((_work), (_func)); \
196 #define INIT_WORK(_work, _func) \
198 __INIT_WORK((_work), (_func), 0); \
201 #define INIT_WORK_ONSTACK(_work, _func) \
203 __INIT_WORK((_work), (_func), 1); \
206 #define INIT_DELAYED_WORK(_work, _func) \
208 INIT_WORK(&(_work)->work, (_func)); \
209 init_timer(&(_work)->timer); \
212 #define INIT_DELAYED_WORK_ONSTACK(_work, _func) \
214 INIT_WORK_ONSTACK(&(_work)->work, (_func)); \
215 init_timer_on_stack(&(_work)->timer); \
218 #define INIT_DELAYED_WORK_DEFERRABLE(_work, _func) \
220 INIT_WORK(&(_work)->work, (_func)); \
221 init_timer_deferrable(&(_work)->timer); \
225 * work_pending - Find out whether a work item is currently pending
226 * @work: The work item in question
228 #define work_pending(work) \
229 test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
232 * delayed_work_pending - Find out whether a delayable work item is currently
234 * @work: The work item in question
236 #define delayed_work_pending(w) \
237 work_pending(&(w)->work)
240 * work_clear_pending - for internal use only, mark a work item as not pending
241 * @work: The work item in question
243 #define work_clear_pending(work) \
244 clear_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
247 * Workqueue flags and constants. For details, please refer to
248 * Documentation/workqueue.txt.
251 WQ_NON_REENTRANT
= 1 << 0, /* guarantee non-reentrance */
252 WQ_UNBOUND
= 1 << 1, /* not bound to any cpu */
253 WQ_FREEZABLE
= 1 << 2, /* freeze during suspend */
254 WQ_MEM_RECLAIM
= 1 << 3, /* may be used for memory reclaim */
255 WQ_HIGHPRI
= 1 << 4, /* high priority */
256 WQ_CPU_INTENSIVE
= 1 << 5, /* cpu instensive workqueue */
258 WQ_DYING
= 1 << 6, /* internal: workqueue is dying */
259 WQ_RESCUER
= 1 << 7, /* internal: workqueue has rescuer */
261 WQ_MAX_ACTIVE
= 512, /* I like 512, better ideas? */
262 WQ_MAX_UNBOUND_PER_CPU
= 4, /* 4 * #cpus for unbound wq */
263 WQ_DFL_ACTIVE
= WQ_MAX_ACTIVE
/ 2,
266 /* unbound wq's aren't per-cpu, scale max_active according to #cpus */
267 #define WQ_UNBOUND_MAX_ACTIVE \
268 max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU)
271 * System-wide workqueues which are always present.
273 * system_wq is the one used by schedule[_delayed]_work[_on]().
274 * Multi-CPU multi-threaded. There are users which expect relatively
275 * short queue flush time. Don't queue works which can run for too
278 * system_long_wq is similar to system_wq but may host long running
279 * works. Queue flushing might take relatively long.
281 * system_nrt_wq is non-reentrant and guarantees that any given work
282 * item is never executed in parallel by multiple CPUs. Queue
283 * flushing might take relatively long.
285 * system_unbound_wq is unbound workqueue. Workers are not bound to
286 * any specific CPU, not concurrency managed, and all queued works are
287 * executed immediately as long as max_active limit is not reached and
288 * resources are available.
290 * system_freezable_wq is equivalent to system_wq except that it's
293 extern struct workqueue_struct
*system_wq
;
294 extern struct workqueue_struct
*system_long_wq
;
295 extern struct workqueue_struct
*system_nrt_wq
;
296 extern struct workqueue_struct
*system_unbound_wq
;
297 extern struct workqueue_struct
*system_freezable_wq
;
299 extern struct workqueue_struct
*
300 __alloc_workqueue_key(const char *name
, unsigned int flags
, int max_active
,
301 struct lock_class_key
*key
, const char *lock_name
);
303 #ifdef CONFIG_LOCKDEP
304 #define alloc_workqueue(name, flags, max_active) \
306 static struct lock_class_key __key; \
307 const char *__lock_name; \
309 if (__builtin_constant_p(name)) \
310 __lock_name = (name); \
312 __lock_name = #name; \
314 __alloc_workqueue_key((name), (flags), (max_active), \
315 &__key, __lock_name); \
318 #define alloc_workqueue(name, flags, max_active) \
319 __alloc_workqueue_key((name), (flags), (max_active), NULL, NULL)
323 * alloc_ordered_workqueue - allocate an ordered workqueue
324 * @name: name of the workqueue
325 * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
327 * Allocate an ordered workqueue. An ordered workqueue executes at
328 * most one work item at any given time in the queued order. They are
329 * implemented as unbound workqueues with @max_active of one.
332 * Pointer to the allocated workqueue on success, %NULL on failure.
334 static inline struct workqueue_struct
*
335 alloc_ordered_workqueue(const char *name
, unsigned int flags
)
337 return alloc_workqueue(name
, WQ_UNBOUND
| flags
, 1);
340 #define create_workqueue(name) \
341 alloc_workqueue((name), WQ_MEM_RECLAIM, 1)
342 #define create_freezable_workqueue(name) \
343 alloc_workqueue((name), WQ_FREEZABLE | WQ_UNBOUND | WQ_MEM_RECLAIM, 1)
344 #define create_singlethread_workqueue(name) \
345 alloc_workqueue((name), WQ_UNBOUND | WQ_MEM_RECLAIM, 1)
347 extern void destroy_workqueue(struct workqueue_struct
*wq
);
349 extern int queue_work(struct workqueue_struct
*wq
, struct work_struct
*work
);
350 extern int queue_work_on(int cpu
, struct workqueue_struct
*wq
,
351 struct work_struct
*work
);
352 extern int queue_delayed_work(struct workqueue_struct
*wq
,
353 struct delayed_work
*work
, unsigned long delay
);
354 extern int queue_delayed_work_on(int cpu
, struct workqueue_struct
*wq
,
355 struct delayed_work
*work
, unsigned long delay
);
357 extern void flush_workqueue(struct workqueue_struct
*wq
);
358 extern void flush_scheduled_work(void);
360 extern int schedule_work(struct work_struct
*work
);
361 extern int schedule_work_on(int cpu
, struct work_struct
*work
);
362 extern int schedule_delayed_work(struct delayed_work
*work
, unsigned long delay
);
363 extern int schedule_delayed_work_on(int cpu
, struct delayed_work
*work
,
364 unsigned long delay
);
365 extern int schedule_on_each_cpu(work_func_t func
);
366 extern int keventd_up(void);
368 int execute_in_process_context(work_func_t fn
, struct execute_work
*);
370 extern bool flush_work(struct work_struct
*work
);
371 extern bool flush_work_sync(struct work_struct
*work
);
372 extern bool cancel_work_sync(struct work_struct
*work
);
374 extern bool flush_delayed_work(struct delayed_work
*dwork
);
375 extern bool flush_delayed_work_sync(struct delayed_work
*work
);
376 extern bool cancel_delayed_work_sync(struct delayed_work
*dwork
);
378 extern void workqueue_set_max_active(struct workqueue_struct
*wq
,
380 extern bool workqueue_congested(unsigned int cpu
, struct workqueue_struct
*wq
);
381 extern unsigned int work_cpu(struct work_struct
*work
);
382 extern unsigned int work_busy(struct work_struct
*work
);
385 * Kill off a pending schedule_delayed_work(). Note that the work callback
386 * function may still be running on return from cancel_delayed_work(), unless
387 * it returns 1 and the work doesn't re-arm itself. Run flush_workqueue() or
388 * cancel_work_sync() to wait on it.
390 static inline bool cancel_delayed_work(struct delayed_work
*work
)
394 ret
= del_timer_sync(&work
->timer
);
396 work_clear_pending(&work
->work
);
401 * Like above, but uses del_timer() instead of del_timer_sync(). This means,
402 * if it returns 0 the timer function may be running and the queueing is in
405 static inline bool __cancel_delayed_work(struct delayed_work
*work
)
409 ret
= del_timer(&work
->timer
);
411 work_clear_pending(&work
->work
);
415 /* Obsolete. use cancel_delayed_work_sync() */
416 static inline __deprecated
417 void cancel_rearming_delayed_workqueue(struct workqueue_struct
*wq
,
418 struct delayed_work
*work
)
420 cancel_delayed_work_sync(work
);
423 /* Obsolete. use cancel_delayed_work_sync() */
424 static inline __deprecated
425 void cancel_rearming_delayed_work(struct delayed_work
*work
)
427 cancel_delayed_work_sync(work
);
431 static inline long work_on_cpu(unsigned int cpu
, long (*fn
)(void *), void *arg
)
436 long work_on_cpu(unsigned int cpu
, long (*fn
)(void *), void *arg
);
437 #endif /* CONFIG_SMP */
439 #ifdef CONFIG_FREEZER
440 extern void freeze_workqueues_begin(void);
441 extern bool freeze_workqueues_busy(void);
442 extern void thaw_workqueues(void);
443 #endif /* CONFIG_FREEZER */