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_CWQ_BIT
= 2, /* data points to cwq */
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_CWQ
= 1 << WORK_STRUCT_CWQ_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_NONE
= NR_CPUS
+ 1,
61 WORK_CPU_LAST
= WORK_CPU_NONE
,
64 * Reserve 7 bits off of cwq pointer w/ debugobjects turned
65 * off. This makes cwqs aligned to 256 bytes and allows 15
66 * workqueue flush colors.
68 WORK_STRUCT_FLAG_BITS
= WORK_STRUCT_COLOR_SHIFT
+
69 WORK_STRUCT_COLOR_BITS
,
71 /* data contains off-queue information when !WORK_STRUCT_CWQ */
72 WORK_OFFQ_FLAG_BASE
= WORK_STRUCT_FLAG_BITS
,
74 WORK_OFFQ_CANCELING
= (1 << WORK_OFFQ_FLAG_BASE
),
76 WORK_OFFQ_FLAG_BITS
= 1,
77 WORK_OFFQ_CPU_SHIFT
= WORK_OFFQ_FLAG_BASE
+ WORK_OFFQ_FLAG_BITS
,
79 /* convenience constants */
80 WORK_STRUCT_FLAG_MASK
= (1UL << WORK_STRUCT_FLAG_BITS
) - 1,
81 WORK_STRUCT_WQ_DATA_MASK
= ~WORK_STRUCT_FLAG_MASK
,
82 WORK_STRUCT_NO_CPU
= (unsigned long)WORK_CPU_NONE
<< WORK_OFFQ_CPU_SHIFT
,
84 /* bit mask for work_busy() return values */
85 WORK_BUSY_PENDING
= 1 << 0,
86 WORK_BUSY_RUNNING
= 1 << 1,
91 struct list_head entry
;
94 struct lockdep_map lockdep_map
;
98 #define WORK_DATA_INIT() ATOMIC_LONG_INIT(WORK_STRUCT_NO_CPU)
99 #define WORK_DATA_STATIC_INIT() \
100 ATOMIC_LONG_INIT(WORK_STRUCT_NO_CPU | WORK_STRUCT_STATIC)
102 struct delayed_work
{
103 struct work_struct work
;
104 struct timer_list timer
;
108 static inline struct delayed_work
*to_delayed_work(struct work_struct
*work
)
110 return container_of(work
, struct delayed_work
, work
);
113 struct execute_work
{
114 struct work_struct work
;
117 #ifdef CONFIG_LOCKDEP
119 * NB: because we have to copy the lockdep_map, setting _key
120 * here is required, otherwise it could get initialised to the
121 * copy of the lockdep_map!
123 #define __WORK_INIT_LOCKDEP_MAP(n, k) \
124 .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
126 #define __WORK_INIT_LOCKDEP_MAP(n, k)
129 #define __WORK_INITIALIZER(n, f) { \
130 .data = WORK_DATA_STATIC_INIT(), \
131 .entry = { &(n).entry, &(n).entry }, \
133 __WORK_INIT_LOCKDEP_MAP(#n, &(n)) \
136 #define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \
137 .work = __WORK_INITIALIZER((n).work, (f)), \
138 .timer = __TIMER_INITIALIZER(delayed_work_timer_fn, \
139 0, (unsigned long)&(n), \
140 (tflags) | TIMER_IRQSAFE), \
143 #define DECLARE_WORK(n, f) \
144 struct work_struct n = __WORK_INITIALIZER(n, f)
146 #define DECLARE_DELAYED_WORK(n, f) \
147 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0)
149 #define DECLARE_DEFERRABLE_WORK(n, f) \
150 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, TIMER_DEFERRABLE)
153 * initialize a work item's function pointer
155 #define PREPARE_WORK(_work, _func) \
157 (_work)->func = (_func); \
160 #define PREPARE_DELAYED_WORK(_work, _func) \
161 PREPARE_WORK(&(_work)->work, (_func))
163 #ifdef CONFIG_DEBUG_OBJECTS_WORK
164 extern void __init_work(struct work_struct
*work
, int onstack
);
165 extern void destroy_work_on_stack(struct work_struct
*work
);
166 static inline unsigned int work_static(struct work_struct
*work
)
168 return *work_data_bits(work
) & WORK_STRUCT_STATIC
;
171 static inline void __init_work(struct work_struct
*work
, int onstack
) { }
172 static inline void destroy_work_on_stack(struct work_struct
*work
) { }
173 static inline unsigned int work_static(struct work_struct
*work
) { return 0; }
177 * initialize all of a work item in one go
179 * NOTE! No point in using "atomic_long_set()": using a direct
180 * assignment of the work data initializer allows the compiler
181 * to generate better code.
183 #ifdef CONFIG_LOCKDEP
184 #define __INIT_WORK(_work, _func, _onstack) \
186 static struct lock_class_key __key; \
188 __init_work((_work), _onstack); \
189 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
190 lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0); \
191 INIT_LIST_HEAD(&(_work)->entry); \
192 PREPARE_WORK((_work), (_func)); \
195 #define __INIT_WORK(_work, _func, _onstack) \
197 __init_work((_work), _onstack); \
198 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
199 INIT_LIST_HEAD(&(_work)->entry); \
200 PREPARE_WORK((_work), (_func)); \
204 #define INIT_WORK(_work, _func) \
206 __INIT_WORK((_work), (_func), 0); \
209 #define INIT_WORK_ONSTACK(_work, _func) \
211 __INIT_WORK((_work), (_func), 1); \
214 #define __INIT_DELAYED_WORK(_work, _func, _tflags) \
216 INIT_WORK(&(_work)->work, (_func)); \
217 __setup_timer(&(_work)->timer, delayed_work_timer_fn, \
218 (unsigned long)(_work), \
219 (_tflags) | TIMER_IRQSAFE); \
222 #define __INIT_DELAYED_WORK_ONSTACK(_work, _func, _tflags) \
224 INIT_WORK_ONSTACK(&(_work)->work, (_func)); \
225 __setup_timer_on_stack(&(_work)->timer, \
226 delayed_work_timer_fn, \
227 (unsigned long)(_work), \
228 (_tflags) | TIMER_IRQSAFE); \
231 #define INIT_DELAYED_WORK(_work, _func) \
232 __INIT_DELAYED_WORK(_work, _func, 0)
234 #define INIT_DELAYED_WORK_ONSTACK(_work, _func) \
235 __INIT_DELAYED_WORK_ONSTACK(_work, _func, 0)
237 #define INIT_DEFERRABLE_WORK(_work, _func) \
238 __INIT_DELAYED_WORK(_work, _func, TIMER_DEFERRABLE)
240 #define INIT_DEFERRABLE_WORK_ONSTACK(_work, _func) \
241 __INIT_DELAYED_WORK_ONSTACK(_work, _func, TIMER_DEFERRABLE)
244 * work_pending - Find out whether a work item is currently pending
245 * @work: The work item in question
247 #define work_pending(work) \
248 test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
251 * delayed_work_pending - Find out whether a delayable work item is currently
253 * @work: The work item in question
255 #define delayed_work_pending(w) \
256 work_pending(&(w)->work)
259 * work_clear_pending - for internal use only, mark a work item as not pending
260 * @work: The work item in question
262 #define work_clear_pending(work) \
263 clear_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
266 * Workqueue flags and constants. For details, please refer to
267 * Documentation/workqueue.txt.
270 WQ_NON_REENTRANT
= 1 << 0, /* guarantee non-reentrance */
271 WQ_UNBOUND
= 1 << 1, /* not bound to any cpu */
272 WQ_FREEZABLE
= 1 << 2, /* freeze during suspend */
273 WQ_MEM_RECLAIM
= 1 << 3, /* may be used for memory reclaim */
274 WQ_HIGHPRI
= 1 << 4, /* high priority */
275 WQ_CPU_INTENSIVE
= 1 << 5, /* cpu instensive workqueue */
277 WQ_DRAINING
= 1 << 6, /* internal: workqueue is draining */
278 WQ_RESCUER
= 1 << 7, /* internal: workqueue has rescuer */
280 WQ_MAX_ACTIVE
= 512, /* I like 512, better ideas? */
281 WQ_MAX_UNBOUND_PER_CPU
= 4, /* 4 * #cpus for unbound wq */
282 WQ_DFL_ACTIVE
= WQ_MAX_ACTIVE
/ 2,
285 /* unbound wq's aren't per-cpu, scale max_active according to #cpus */
286 #define WQ_UNBOUND_MAX_ACTIVE \
287 max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU)
290 * System-wide workqueues which are always present.
292 * system_wq is the one used by schedule[_delayed]_work[_on]().
293 * Multi-CPU multi-threaded. There are users which expect relatively
294 * short queue flush time. Don't queue works which can run for too
297 * system_long_wq is similar to system_wq but may host long running
298 * works. Queue flushing might take relatively long.
300 * system_unbound_wq is unbound workqueue. Workers are not bound to
301 * any specific CPU, not concurrency managed, and all queued works are
302 * executed immediately as long as max_active limit is not reached and
303 * resources are available.
305 * system_freezable_wq is equivalent to system_wq except that it's
308 extern struct workqueue_struct
*system_wq
;
309 extern struct workqueue_struct
*system_long_wq
;
310 extern struct workqueue_struct
*system_unbound_wq
;
311 extern struct workqueue_struct
*system_freezable_wq
;
313 static inline struct workqueue_struct
* __deprecated
__system_nrt_wq(void)
318 static inline struct workqueue_struct
* __deprecated
__system_nrt_freezable_wq(void)
320 return system_freezable_wq
;
323 /* equivlalent to system_wq and system_freezable_wq, deprecated */
324 #define system_nrt_wq __system_nrt_wq()
325 #define system_nrt_freezable_wq __system_nrt_freezable_wq()
327 extern struct workqueue_struct
*
328 __alloc_workqueue_key(const char *fmt
, unsigned int flags
, int max_active
,
329 struct lock_class_key
*key
, const char *lock_name
, ...) __printf(1, 6);
332 * alloc_workqueue - allocate a workqueue
333 * @fmt: printf format for the name of the workqueue
335 * @max_active: max in-flight work items, 0 for default
336 * @args: args for @fmt
338 * Allocate a workqueue with the specified parameters. For detailed
339 * information on WQ_* flags, please refer to Documentation/workqueue.txt.
341 * The __lock_name macro dance is to guarantee that single lock_class_key
342 * doesn't end up with different namesm, which isn't allowed by lockdep.
345 * Pointer to the allocated workqueue on success, %NULL on failure.
347 #ifdef CONFIG_LOCKDEP
348 #define alloc_workqueue(fmt, flags, max_active, args...) \
350 static struct lock_class_key __key; \
351 const char *__lock_name; \
353 if (__builtin_constant_p(fmt)) \
354 __lock_name = (fmt); \
356 __lock_name = #fmt; \
358 __alloc_workqueue_key((fmt), (flags), (max_active), \
359 &__key, __lock_name, ##args); \
362 #define alloc_workqueue(fmt, flags, max_active, args...) \
363 __alloc_workqueue_key((fmt), (flags), (max_active), \
368 * alloc_ordered_workqueue - allocate an ordered workqueue
369 * @fmt: printf format for the name of the workqueue
370 * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
371 * @args: args for @fmt
373 * Allocate an ordered workqueue. An ordered workqueue executes at
374 * most one work item at any given time in the queued order. They are
375 * implemented as unbound workqueues with @max_active of one.
378 * Pointer to the allocated workqueue on success, %NULL on failure.
380 #define alloc_ordered_workqueue(fmt, flags, args...) \
381 alloc_workqueue(fmt, WQ_UNBOUND | (flags), 1, ##args)
383 #define create_workqueue(name) \
384 alloc_workqueue((name), WQ_MEM_RECLAIM, 1)
385 #define create_freezable_workqueue(name) \
386 alloc_workqueue((name), WQ_FREEZABLE | WQ_UNBOUND | WQ_MEM_RECLAIM, 1)
387 #define create_singlethread_workqueue(name) \
388 alloc_workqueue((name), WQ_UNBOUND | WQ_MEM_RECLAIM, 1)
390 extern void destroy_workqueue(struct workqueue_struct
*wq
);
392 extern bool queue_work_on(int cpu
, struct workqueue_struct
*wq
,
393 struct work_struct
*work
);
394 extern bool queue_work(struct workqueue_struct
*wq
, struct work_struct
*work
);
395 extern bool queue_delayed_work_on(int cpu
, struct workqueue_struct
*wq
,
396 struct delayed_work
*work
, unsigned long delay
);
397 extern bool queue_delayed_work(struct workqueue_struct
*wq
,
398 struct delayed_work
*work
, unsigned long delay
);
399 extern bool mod_delayed_work_on(int cpu
, struct workqueue_struct
*wq
,
400 struct delayed_work
*dwork
, unsigned long delay
);
401 extern bool mod_delayed_work(struct workqueue_struct
*wq
,
402 struct delayed_work
*dwork
, unsigned long delay
);
404 extern void flush_workqueue(struct workqueue_struct
*wq
);
405 extern void drain_workqueue(struct workqueue_struct
*wq
);
406 extern void flush_scheduled_work(void);
408 extern bool schedule_work_on(int cpu
, struct work_struct
*work
);
409 extern bool schedule_work(struct work_struct
*work
);
410 extern bool schedule_delayed_work_on(int cpu
, struct delayed_work
*work
,
411 unsigned long delay
);
412 extern bool schedule_delayed_work(struct delayed_work
*work
,
413 unsigned long delay
);
414 extern int schedule_on_each_cpu(work_func_t func
);
415 extern int keventd_up(void);
417 int execute_in_process_context(work_func_t fn
, struct execute_work
*);
419 extern bool flush_work(struct work_struct
*work
);
420 extern bool cancel_work_sync(struct work_struct
*work
);
422 extern bool flush_delayed_work(struct delayed_work
*dwork
);
423 extern bool cancel_delayed_work(struct delayed_work
*dwork
);
424 extern bool cancel_delayed_work_sync(struct delayed_work
*dwork
);
426 extern void workqueue_set_max_active(struct workqueue_struct
*wq
,
428 extern bool workqueue_congested(unsigned int cpu
, struct workqueue_struct
*wq
);
429 extern unsigned int work_cpu(struct work_struct
*work
);
430 extern unsigned int work_busy(struct work_struct
*work
);
433 * Like above, but uses del_timer() instead of del_timer_sync(). This means,
434 * if it returns 0 the timer function may be running and the queueing is in
437 static inline bool __deprecated
__cancel_delayed_work(struct delayed_work
*work
)
441 ret
= del_timer(&work
->timer
);
443 work_clear_pending(&work
->work
);
447 /* used to be different but now identical to flush_work(), deprecated */
448 static inline bool __deprecated
flush_work_sync(struct work_struct
*work
)
450 return flush_work(work
);
453 /* used to be different but now identical to flush_delayed_work(), deprecated */
454 static inline bool __deprecated
flush_delayed_work_sync(struct delayed_work
*dwork
)
456 return flush_delayed_work(dwork
);
460 static inline long work_on_cpu(unsigned int cpu
, long (*fn
)(void *), void *arg
)
465 long work_on_cpu(unsigned int cpu
, long (*fn
)(void *), void *arg
);
466 #endif /* CONFIG_SMP */
468 #ifdef CONFIG_FREEZER
469 extern void freeze_workqueues_begin(void);
470 extern bool freeze_workqueues_busy(void);
471 extern void thaw_workqueues(void);
472 #endif /* CONFIG_FREEZER */
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