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 <linux/atomic.h>
15 struct workqueue_struct
;
18 typedef void (*work_func_t
)(struct work_struct
*work
);
19 void delayed_work_timer_fn(unsigned long __data
);
22 * The first word is the work queue pointer and the flags rolled into
25 #define work_data_bits(work) ((unsigned long *)(&(work)->data))
28 WORK_STRUCT_PENDING_BIT
= 0, /* work item is pending execution */
29 WORK_STRUCT_DELAYED_BIT
= 1, /* work item is delayed */
30 WORK_STRUCT_PWQ_BIT
= 2, /* data points to pwq */
31 WORK_STRUCT_LINKED_BIT
= 3, /* next work is linked to this one */
32 #ifdef CONFIG_DEBUG_OBJECTS_WORK
33 WORK_STRUCT_STATIC_BIT
= 4, /* static initializer (debugobjects) */
34 WORK_STRUCT_COLOR_SHIFT
= 5, /* color for workqueue flushing */
36 WORK_STRUCT_COLOR_SHIFT
= 4, /* color for workqueue flushing */
39 WORK_STRUCT_COLOR_BITS
= 4,
41 WORK_STRUCT_PENDING
= 1 << WORK_STRUCT_PENDING_BIT
,
42 WORK_STRUCT_DELAYED
= 1 << WORK_STRUCT_DELAYED_BIT
,
43 WORK_STRUCT_PWQ
= 1 << WORK_STRUCT_PWQ_BIT
,
44 WORK_STRUCT_LINKED
= 1 << WORK_STRUCT_LINKED_BIT
,
45 #ifdef CONFIG_DEBUG_OBJECTS_WORK
46 WORK_STRUCT_STATIC
= 1 << WORK_STRUCT_STATIC_BIT
,
48 WORK_STRUCT_STATIC
= 0,
52 * The last color is no color used for works which don't
53 * participate in workqueue flushing.
55 WORK_NR_COLORS
= (1 << WORK_STRUCT_COLOR_BITS
) - 1,
56 WORK_NO_COLOR
= WORK_NR_COLORS
,
59 WORK_CPU_UNBOUND
= NR_CPUS
,
60 WORK_CPU_END
= NR_CPUS
+ 1,
63 * Reserve 7 bits off of pwq pointer w/ debugobjects turned off.
64 * This makes pwqs aligned to 256 bytes and allows 15 workqueue
67 WORK_STRUCT_FLAG_BITS
= WORK_STRUCT_COLOR_SHIFT
+
68 WORK_STRUCT_COLOR_BITS
,
70 /* data contains off-queue information when !WORK_STRUCT_PWQ */
71 WORK_OFFQ_FLAG_BASE
= WORK_STRUCT_FLAG_BITS
,
73 WORK_OFFQ_CANCELING
= (1 << WORK_OFFQ_FLAG_BASE
),
76 * When a work item is off queue, its high bits point to the last
77 * pool it was on. Cap at 31 bits and use the highest number to
78 * indicate that no pool is associated.
80 WORK_OFFQ_FLAG_BITS
= 1,
81 WORK_OFFQ_POOL_SHIFT
= WORK_OFFQ_FLAG_BASE
+ WORK_OFFQ_FLAG_BITS
,
82 WORK_OFFQ_LEFT
= BITS_PER_LONG
- WORK_OFFQ_POOL_SHIFT
,
83 WORK_OFFQ_POOL_BITS
= WORK_OFFQ_LEFT
<= 31 ? WORK_OFFQ_LEFT
: 31,
84 WORK_OFFQ_POOL_NONE
= (1LU << WORK_OFFQ_POOL_BITS
) - 1,
86 /* convenience constants */
87 WORK_STRUCT_FLAG_MASK
= (1UL << WORK_STRUCT_FLAG_BITS
) - 1,
88 WORK_STRUCT_WQ_DATA_MASK
= ~WORK_STRUCT_FLAG_MASK
,
89 WORK_STRUCT_NO_POOL
= (unsigned long)WORK_OFFQ_POOL_NONE
<< WORK_OFFQ_POOL_SHIFT
,
91 /* bit mask for work_busy() return values */
92 WORK_BUSY_PENDING
= 1 << 0,
93 WORK_BUSY_RUNNING
= 1 << 1,
98 struct list_head entry
;
100 #ifdef CONFIG_LOCKDEP
101 struct lockdep_map lockdep_map
;
105 #define WORK_DATA_INIT() ATOMIC_LONG_INIT(WORK_STRUCT_NO_POOL)
106 #define WORK_DATA_STATIC_INIT() \
107 ATOMIC_LONG_INIT(WORK_STRUCT_NO_POOL | WORK_STRUCT_STATIC)
109 struct delayed_work
{
110 struct work_struct work
;
111 struct timer_list timer
;
113 /* target workqueue and CPU ->timer uses to queue ->work */
114 struct workqueue_struct
*wq
;
118 static inline struct delayed_work
*to_delayed_work(struct work_struct
*work
)
120 return container_of(work
, struct delayed_work
, work
);
123 struct execute_work
{
124 struct work_struct work
;
127 #ifdef CONFIG_LOCKDEP
129 * NB: because we have to copy the lockdep_map, setting _key
130 * here is required, otherwise it could get initialised to the
131 * copy of the lockdep_map!
133 #define __WORK_INIT_LOCKDEP_MAP(n, k) \
134 .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
136 #define __WORK_INIT_LOCKDEP_MAP(n, k)
139 #define __WORK_INITIALIZER(n, f) { \
140 .data = WORK_DATA_STATIC_INIT(), \
141 .entry = { &(n).entry, &(n).entry }, \
143 __WORK_INIT_LOCKDEP_MAP(#n, &(n)) \
146 #define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \
147 .work = __WORK_INITIALIZER((n).work, (f)), \
148 .timer = __TIMER_INITIALIZER(delayed_work_timer_fn, \
149 0, (unsigned long)&(n), \
150 (tflags) | TIMER_IRQSAFE), \
153 #define DECLARE_WORK(n, f) \
154 struct work_struct n = __WORK_INITIALIZER(n, f)
156 #define DECLARE_DELAYED_WORK(n, f) \
157 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0)
159 #define DECLARE_DEFERRABLE_WORK(n, f) \
160 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, TIMER_DEFERRABLE)
163 * initialize a work item's function pointer
165 #define PREPARE_WORK(_work, _func) \
167 (_work)->func = (_func); \
170 #define PREPARE_DELAYED_WORK(_work, _func) \
171 PREPARE_WORK(&(_work)->work, (_func))
173 #ifdef CONFIG_DEBUG_OBJECTS_WORK
174 extern void __init_work(struct work_struct
*work
, int onstack
);
175 extern void destroy_work_on_stack(struct work_struct
*work
);
176 static inline unsigned int work_static(struct work_struct
*work
)
178 return *work_data_bits(work
) & WORK_STRUCT_STATIC
;
181 static inline void __init_work(struct work_struct
*work
, int onstack
) { }
182 static inline void destroy_work_on_stack(struct work_struct
*work
) { }
183 static inline unsigned int work_static(struct work_struct
*work
) { return 0; }
187 * initialize all of a work item in one go
189 * NOTE! No point in using "atomic_long_set()": using a direct
190 * assignment of the work data initializer allows the compiler
191 * to generate better code.
193 #ifdef CONFIG_LOCKDEP
194 #define __INIT_WORK(_work, _func, _onstack) \
196 static struct lock_class_key __key; \
198 __init_work((_work), _onstack); \
199 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
200 lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0); \
201 INIT_LIST_HEAD(&(_work)->entry); \
202 PREPARE_WORK((_work), (_func)); \
205 #define __INIT_WORK(_work, _func, _onstack) \
207 __init_work((_work), _onstack); \
208 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
209 INIT_LIST_HEAD(&(_work)->entry); \
210 PREPARE_WORK((_work), (_func)); \
214 #define INIT_WORK(_work, _func) \
216 __INIT_WORK((_work), (_func), 0); \
219 #define INIT_WORK_ONSTACK(_work, _func) \
221 __INIT_WORK((_work), (_func), 1); \
224 #define __INIT_DELAYED_WORK(_work, _func, _tflags) \
226 INIT_WORK(&(_work)->work, (_func)); \
227 __setup_timer(&(_work)->timer, delayed_work_timer_fn, \
228 (unsigned long)(_work), \
229 (_tflags) | TIMER_IRQSAFE); \
232 #define __INIT_DELAYED_WORK_ONSTACK(_work, _func, _tflags) \
234 INIT_WORK_ONSTACK(&(_work)->work, (_func)); \
235 __setup_timer_on_stack(&(_work)->timer, \
236 delayed_work_timer_fn, \
237 (unsigned long)(_work), \
238 (_tflags) | TIMER_IRQSAFE); \
241 #define INIT_DELAYED_WORK(_work, _func) \
242 __INIT_DELAYED_WORK(_work, _func, 0)
244 #define INIT_DELAYED_WORK_ONSTACK(_work, _func) \
245 __INIT_DELAYED_WORK_ONSTACK(_work, _func, 0)
247 #define INIT_DEFERRABLE_WORK(_work, _func) \
248 __INIT_DELAYED_WORK(_work, _func, TIMER_DEFERRABLE)
250 #define INIT_DEFERRABLE_WORK_ONSTACK(_work, _func) \
251 __INIT_DELAYED_WORK_ONSTACK(_work, _func, TIMER_DEFERRABLE)
254 * work_pending - Find out whether a work item is currently pending
255 * @work: The work item in question
257 #define work_pending(work) \
258 test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
261 * delayed_work_pending - Find out whether a delayable work item is currently
263 * @work: The work item in question
265 #define delayed_work_pending(w) \
266 work_pending(&(w)->work)
269 * work_clear_pending - for internal use only, mark a work item as not pending
270 * @work: The work item in question
272 #define work_clear_pending(work) \
273 clear_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
276 * Workqueue flags and constants. For details, please refer to
277 * Documentation/workqueue.txt.
280 WQ_NON_REENTRANT
= 1 << 0, /* guarantee non-reentrance */
281 WQ_UNBOUND
= 1 << 1, /* not bound to any cpu */
282 WQ_FREEZABLE
= 1 << 2, /* freeze during suspend */
283 WQ_MEM_RECLAIM
= 1 << 3, /* may be used for memory reclaim */
284 WQ_HIGHPRI
= 1 << 4, /* high priority */
285 WQ_CPU_INTENSIVE
= 1 << 5, /* cpu instensive workqueue */
287 WQ_DRAINING
= 1 << 6, /* internal: workqueue is draining */
288 WQ_RESCUER
= 1 << 7, /* internal: workqueue has rescuer */
290 WQ_MAX_ACTIVE
= 512, /* I like 512, better ideas? */
291 WQ_MAX_UNBOUND_PER_CPU
= 4, /* 4 * #cpus for unbound wq */
292 WQ_DFL_ACTIVE
= WQ_MAX_ACTIVE
/ 2,
295 /* unbound wq's aren't per-cpu, scale max_active according to #cpus */
296 #define WQ_UNBOUND_MAX_ACTIVE \
297 max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU)
300 * System-wide workqueues which are always present.
302 * system_wq is the one used by schedule[_delayed]_work[_on]().
303 * Multi-CPU multi-threaded. There are users which expect relatively
304 * short queue flush time. Don't queue works which can run for too
307 * system_long_wq is similar to system_wq but may host long running
308 * works. Queue flushing might take relatively long.
310 * system_unbound_wq is unbound workqueue. Workers are not bound to
311 * any specific CPU, not concurrency managed, and all queued works are
312 * executed immediately as long as max_active limit is not reached and
313 * resources are available.
315 * system_freezable_wq is equivalent to system_wq except that it's
318 extern struct workqueue_struct
*system_wq
;
319 extern struct workqueue_struct
*system_long_wq
;
320 extern struct workqueue_struct
*system_unbound_wq
;
321 extern struct workqueue_struct
*system_freezable_wq
;
323 static inline struct workqueue_struct
* __deprecated
__system_nrt_wq(void)
328 static inline struct workqueue_struct
* __deprecated
__system_nrt_freezable_wq(void)
330 return system_freezable_wq
;
333 /* equivlalent to system_wq and system_freezable_wq, deprecated */
334 #define system_nrt_wq __system_nrt_wq()
335 #define system_nrt_freezable_wq __system_nrt_freezable_wq()
337 extern struct workqueue_struct
*
338 __alloc_workqueue_key(const char *fmt
, unsigned int flags
, int max_active
,
339 struct lock_class_key
*key
, const char *lock_name
, ...) __printf(1, 6);
342 * alloc_workqueue - allocate a workqueue
343 * @fmt: printf format for the name of the workqueue
345 * @max_active: max in-flight work items, 0 for default
346 * @args: args for @fmt
348 * Allocate a workqueue with the specified parameters. For detailed
349 * information on WQ_* flags, please refer to Documentation/workqueue.txt.
351 * The __lock_name macro dance is to guarantee that single lock_class_key
352 * doesn't end up with different namesm, which isn't allowed by lockdep.
355 * Pointer to the allocated workqueue on success, %NULL on failure.
357 #ifdef CONFIG_LOCKDEP
358 #define alloc_workqueue(fmt, flags, max_active, args...) \
360 static struct lock_class_key __key; \
361 const char *__lock_name; \
363 if (__builtin_constant_p(fmt)) \
364 __lock_name = (fmt); \
366 __lock_name = #fmt; \
368 __alloc_workqueue_key((fmt), (flags), (max_active), \
369 &__key, __lock_name, ##args); \
372 #define alloc_workqueue(fmt, flags, max_active, args...) \
373 __alloc_workqueue_key((fmt), (flags), (max_active), \
378 * alloc_ordered_workqueue - allocate an ordered workqueue
379 * @fmt: printf format for the name of the workqueue
380 * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
381 * @args: args for @fmt
383 * Allocate an ordered workqueue. An ordered workqueue executes at
384 * most one work item at any given time in the queued order. They are
385 * implemented as unbound workqueues with @max_active of one.
388 * Pointer to the allocated workqueue on success, %NULL on failure.
390 #define alloc_ordered_workqueue(fmt, flags, args...) \
391 alloc_workqueue(fmt, WQ_UNBOUND | (flags), 1, ##args)
393 #define create_workqueue(name) \
394 alloc_workqueue((name), WQ_MEM_RECLAIM, 1)
395 #define create_freezable_workqueue(name) \
396 alloc_workqueue((name), WQ_FREEZABLE | WQ_UNBOUND | WQ_MEM_RECLAIM, 1)
397 #define create_singlethread_workqueue(name) \
398 alloc_workqueue((name), WQ_UNBOUND | WQ_MEM_RECLAIM, 1)
400 extern void destroy_workqueue(struct workqueue_struct
*wq
);
402 extern bool queue_work_on(int cpu
, struct workqueue_struct
*wq
,
403 struct work_struct
*work
);
404 extern bool queue_work(struct workqueue_struct
*wq
, struct work_struct
*work
);
405 extern bool queue_delayed_work_on(int cpu
, struct workqueue_struct
*wq
,
406 struct delayed_work
*work
, unsigned long delay
);
407 extern bool queue_delayed_work(struct workqueue_struct
*wq
,
408 struct delayed_work
*work
, unsigned long delay
);
409 extern bool mod_delayed_work_on(int cpu
, struct workqueue_struct
*wq
,
410 struct delayed_work
*dwork
, unsigned long delay
);
411 extern bool mod_delayed_work(struct workqueue_struct
*wq
,
412 struct delayed_work
*dwork
, unsigned long delay
);
414 extern void flush_workqueue(struct workqueue_struct
*wq
);
415 extern void drain_workqueue(struct workqueue_struct
*wq
);
416 extern void flush_scheduled_work(void);
418 extern bool schedule_work_on(int cpu
, struct work_struct
*work
);
419 extern bool schedule_work(struct work_struct
*work
);
420 extern bool schedule_delayed_work_on(int cpu
, struct delayed_work
*work
,
421 unsigned long delay
);
422 extern bool schedule_delayed_work(struct delayed_work
*work
,
423 unsigned long delay
);
424 extern int schedule_on_each_cpu(work_func_t func
);
425 extern int keventd_up(void);
427 int execute_in_process_context(work_func_t fn
, struct execute_work
*);
429 extern bool flush_work(struct work_struct
*work
);
430 extern bool cancel_work_sync(struct work_struct
*work
);
432 extern bool flush_delayed_work(struct delayed_work
*dwork
);
433 extern bool cancel_delayed_work(struct delayed_work
*dwork
);
434 extern bool cancel_delayed_work_sync(struct delayed_work
*dwork
);
436 extern void workqueue_set_max_active(struct workqueue_struct
*wq
,
438 extern bool workqueue_congested(unsigned int cpu
, struct workqueue_struct
*wq
);
439 extern unsigned int work_busy(struct work_struct
*work
);
442 * Like above, but uses del_timer() instead of del_timer_sync(). This means,
443 * if it returns 0 the timer function may be running and the queueing is in
446 static inline bool __deprecated
__cancel_delayed_work(struct delayed_work
*work
)
450 ret
= del_timer(&work
->timer
);
452 work_clear_pending(&work
->work
);
456 /* used to be different but now identical to flush_work(), deprecated */
457 static inline bool __deprecated
flush_work_sync(struct work_struct
*work
)
459 return flush_work(work
);
462 /* used to be different but now identical to flush_delayed_work(), deprecated */
463 static inline bool __deprecated
flush_delayed_work_sync(struct delayed_work
*dwork
)
465 return flush_delayed_work(dwork
);
469 static inline long work_on_cpu(unsigned int cpu
, long (*fn
)(void *), void *arg
)
474 long work_on_cpu(unsigned int cpu
, long (*fn
)(void *), void *arg
);
475 #endif /* CONFIG_SMP */
477 #ifdef CONFIG_FREEZER
478 extern void freeze_workqueues_begin(void);
479 extern bool freeze_workqueues_busy(void);
480 extern void thaw_workqueues(void);
481 #endif /* CONFIG_FREEZER */