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
,
73 WORK_OFFQ_FLAG_BITS
= 0,
74 WORK_OFFQ_CPU_SHIFT
= WORK_OFFQ_FLAG_BASE
+ WORK_OFFQ_FLAG_BITS
,
76 /* convenience constants */
77 WORK_STRUCT_FLAG_MASK
= (1UL << WORK_STRUCT_FLAG_BITS
) - 1,
78 WORK_STRUCT_WQ_DATA_MASK
= ~WORK_STRUCT_FLAG_MASK
,
79 WORK_STRUCT_NO_CPU
= (unsigned long)WORK_CPU_NONE
<< WORK_OFFQ_CPU_SHIFT
,
81 /* bit mask for work_busy() return values */
82 WORK_BUSY_PENDING
= 1 << 0,
83 WORK_BUSY_RUNNING
= 1 << 1,
88 struct list_head entry
;
91 struct lockdep_map lockdep_map
;
95 #define WORK_DATA_INIT() ATOMIC_LONG_INIT(WORK_STRUCT_NO_CPU)
96 #define WORK_DATA_STATIC_INIT() \
97 ATOMIC_LONG_INIT(WORK_STRUCT_NO_CPU | WORK_STRUCT_STATIC)
100 struct work_struct work
;
101 struct timer_list timer
;
104 static inline struct delayed_work
*to_delayed_work(struct work_struct
*work
)
106 return container_of(work
, struct delayed_work
, work
);
109 struct execute_work
{
110 struct work_struct work
;
113 #ifdef CONFIG_LOCKDEP
115 * NB: because we have to copy the lockdep_map, setting _key
116 * here is required, otherwise it could get initialised to the
117 * copy of the lockdep_map!
119 #define __WORK_INIT_LOCKDEP_MAP(n, k) \
120 .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
122 #define __WORK_INIT_LOCKDEP_MAP(n, k)
125 #define __WORK_INITIALIZER(n, f) { \
126 .data = WORK_DATA_STATIC_INIT(), \
127 .entry = { &(n).entry, &(n).entry }, \
129 __WORK_INIT_LOCKDEP_MAP(#n, &(n)) \
132 #define __DELAYED_WORK_INITIALIZER(n, f) { \
133 .work = __WORK_INITIALIZER((n).work, (f)), \
134 .timer = TIMER_INITIALIZER(delayed_work_timer_fn, \
135 0, (unsigned long)&(n)), \
138 #define __DEFERRED_WORK_INITIALIZER(n, f) { \
139 .work = __WORK_INITIALIZER((n).work, (f)), \
140 .timer = TIMER_DEFERRED_INITIALIZER(delayed_work_timer_fn, \
141 0, (unsigned long)&(n)), \
144 #define DECLARE_WORK(n, f) \
145 struct work_struct n = __WORK_INITIALIZER(n, f)
147 #define DECLARE_DELAYED_WORK(n, f) \
148 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f)
150 #define DECLARE_DEFERRED_WORK(n, f) \
151 struct delayed_work n = __DEFERRED_WORK_INITIALIZER(n, f)
154 * initialize a work item's function pointer
156 #define PREPARE_WORK(_work, _func) \
158 (_work)->func = (_func); \
161 #define PREPARE_DELAYED_WORK(_work, _func) \
162 PREPARE_WORK(&(_work)->work, (_func))
164 #ifdef CONFIG_DEBUG_OBJECTS_WORK
165 extern void __init_work(struct work_struct
*work
, int onstack
);
166 extern void destroy_work_on_stack(struct work_struct
*work
);
167 static inline unsigned int work_static(struct work_struct
*work
)
169 return *work_data_bits(work
) & WORK_STRUCT_STATIC
;
172 static inline void __init_work(struct work_struct
*work
, int onstack
) { }
173 static inline void destroy_work_on_stack(struct work_struct
*work
) { }
174 static inline unsigned int work_static(struct work_struct
*work
) { return 0; }
178 * initialize all of a work item in one go
180 * NOTE! No point in using "atomic_long_set()": using a direct
181 * assignment of the work data initializer allows the compiler
182 * to generate better code.
184 #ifdef CONFIG_LOCKDEP
185 #define __INIT_WORK(_work, _func, _onstack) \
187 static struct lock_class_key __key; \
189 __init_work((_work), _onstack); \
190 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
191 lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0);\
192 INIT_LIST_HEAD(&(_work)->entry); \
193 PREPARE_WORK((_work), (_func)); \
196 #define __INIT_WORK(_work, _func, _onstack) \
198 __init_work((_work), _onstack); \
199 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
200 INIT_LIST_HEAD(&(_work)->entry); \
201 PREPARE_WORK((_work), (_func)); \
205 #define INIT_WORK(_work, _func) \
207 __INIT_WORK((_work), (_func), 0); \
210 #define INIT_WORK_ONSTACK(_work, _func) \
212 __INIT_WORK((_work), (_func), 1); \
215 #define INIT_DELAYED_WORK(_work, _func) \
217 INIT_WORK(&(_work)->work, (_func)); \
218 init_timer(&(_work)->timer); \
219 (_work)->timer.function = delayed_work_timer_fn;\
220 (_work)->timer.data = (unsigned long)(_work); \
223 #define INIT_DELAYED_WORK_ONSTACK(_work, _func) \
225 INIT_WORK_ONSTACK(&(_work)->work, (_func)); \
226 init_timer_on_stack(&(_work)->timer); \
227 (_work)->timer.function = delayed_work_timer_fn;\
228 (_work)->timer.data = (unsigned long)(_work); \
231 #define INIT_DELAYED_WORK_DEFERRABLE(_work, _func) \
233 INIT_WORK(&(_work)->work, (_func)); \
234 init_timer_deferrable(&(_work)->timer); \
235 (_work)->timer.function = delayed_work_timer_fn;\
236 (_work)->timer.data = (unsigned long)(_work); \
240 * work_pending - Find out whether a work item is currently pending
241 * @work: The work item in question
243 #define work_pending(work) \
244 test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
247 * delayed_work_pending - Find out whether a delayable work item is currently
249 * @work: The work item in question
251 #define delayed_work_pending(w) \
252 work_pending(&(w)->work)
255 * work_clear_pending - for internal use only, mark a work item as not pending
256 * @work: The work item in question
258 #define work_clear_pending(work) \
259 clear_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
262 * Workqueue flags and constants. For details, please refer to
263 * Documentation/workqueue.txt.
266 WQ_NON_REENTRANT
= 1 << 0, /* guarantee non-reentrance */
267 WQ_UNBOUND
= 1 << 1, /* not bound to any cpu */
268 WQ_FREEZABLE
= 1 << 2, /* freeze during suspend */
269 WQ_MEM_RECLAIM
= 1 << 3, /* may be used for memory reclaim */
270 WQ_HIGHPRI
= 1 << 4, /* high priority */
271 WQ_CPU_INTENSIVE
= 1 << 5, /* cpu instensive workqueue */
273 WQ_DRAINING
= 1 << 6, /* internal: workqueue is draining */
274 WQ_RESCUER
= 1 << 7, /* internal: workqueue has rescuer */
276 WQ_MAX_ACTIVE
= 512, /* I like 512, better ideas? */
277 WQ_MAX_UNBOUND_PER_CPU
= 4, /* 4 * #cpus for unbound wq */
278 WQ_DFL_ACTIVE
= WQ_MAX_ACTIVE
/ 2,
281 /* unbound wq's aren't per-cpu, scale max_active according to #cpus */
282 #define WQ_UNBOUND_MAX_ACTIVE \
283 max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU)
286 * System-wide workqueues which are always present.
288 * system_wq is the one used by schedule[_delayed]_work[_on]().
289 * Multi-CPU multi-threaded. There are users which expect relatively
290 * short queue flush time. Don't queue works which can run for too
293 * system_long_wq is similar to system_wq but may host long running
294 * works. Queue flushing might take relatively long.
296 * system_nrt_wq is non-reentrant and guarantees that any given work
297 * item is never executed in parallel by multiple CPUs. Queue
298 * 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 * system_nrt_freezable_wq is equivalent to system_nrt_wq except that
311 extern struct workqueue_struct
*system_wq
;
312 extern struct workqueue_struct
*system_long_wq
;
313 extern struct workqueue_struct
*system_nrt_wq
;
314 extern struct workqueue_struct
*system_unbound_wq
;
315 extern struct workqueue_struct
*system_freezable_wq
;
316 extern struct workqueue_struct
*system_nrt_freezable_wq
;
318 extern struct workqueue_struct
*
319 __alloc_workqueue_key(const char *fmt
, unsigned int flags
, int max_active
,
320 struct lock_class_key
*key
, const char *lock_name
, ...) __printf(1, 6);
323 * alloc_workqueue - allocate a workqueue
324 * @fmt: printf format for the name of the workqueue
326 * @max_active: max in-flight work items, 0 for default
327 * @args: args for @fmt
329 * Allocate a workqueue with the specified parameters. For detailed
330 * information on WQ_* flags, please refer to Documentation/workqueue.txt.
332 * The __lock_name macro dance is to guarantee that single lock_class_key
333 * doesn't end up with different namesm, which isn't allowed by lockdep.
336 * Pointer to the allocated workqueue on success, %NULL on failure.
338 #ifdef CONFIG_LOCKDEP
339 #define alloc_workqueue(fmt, flags, max_active, args...) \
341 static struct lock_class_key __key; \
342 const char *__lock_name; \
344 if (__builtin_constant_p(fmt)) \
345 __lock_name = (fmt); \
347 __lock_name = #fmt; \
349 __alloc_workqueue_key((fmt), (flags), (max_active), \
350 &__key, __lock_name, ##args); \
353 #define alloc_workqueue(fmt, flags, max_active, args...) \
354 __alloc_workqueue_key((fmt), (flags), (max_active), \
359 * alloc_ordered_workqueue - allocate an ordered workqueue
360 * @fmt: printf format for the name of the workqueue
361 * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
362 * @args: args for @fmt
364 * Allocate an ordered workqueue. An ordered workqueue executes at
365 * most one work item at any given time in the queued order. They are
366 * implemented as unbound workqueues with @max_active of one.
369 * Pointer to the allocated workqueue on success, %NULL on failure.
371 #define alloc_ordered_workqueue(fmt, flags, args...) \
372 alloc_workqueue(fmt, WQ_UNBOUND | (flags), 1, ##args)
374 #define create_workqueue(name) \
375 alloc_workqueue((name), WQ_MEM_RECLAIM, 1)
376 #define create_freezable_workqueue(name) \
377 alloc_workqueue((name), WQ_FREEZABLE | WQ_UNBOUND | WQ_MEM_RECLAIM, 1)
378 #define create_singlethread_workqueue(name) \
379 alloc_workqueue((name), WQ_UNBOUND | WQ_MEM_RECLAIM, 1)
381 extern void destroy_workqueue(struct workqueue_struct
*wq
);
383 extern bool queue_work_on(int cpu
, struct workqueue_struct
*wq
,
384 struct work_struct
*work
);
385 extern bool queue_work(struct workqueue_struct
*wq
, struct work_struct
*work
);
386 extern bool queue_delayed_work_on(int cpu
, struct workqueue_struct
*wq
,
387 struct delayed_work
*work
, unsigned long delay
);
388 extern bool queue_delayed_work(struct workqueue_struct
*wq
,
389 struct delayed_work
*work
, unsigned long delay
);
391 extern void flush_workqueue(struct workqueue_struct
*wq
);
392 extern void drain_workqueue(struct workqueue_struct
*wq
);
393 extern void flush_scheduled_work(void);
395 extern bool schedule_work_on(int cpu
, struct work_struct
*work
);
396 extern bool schedule_work(struct work_struct
*work
);
397 extern bool schedule_delayed_work_on(int cpu
, struct delayed_work
*work
,
398 unsigned long delay
);
399 extern bool schedule_delayed_work(struct delayed_work
*work
,
400 unsigned long delay
);
401 extern int schedule_on_each_cpu(work_func_t func
);
402 extern int keventd_up(void);
404 int execute_in_process_context(work_func_t fn
, struct execute_work
*);
406 extern bool flush_work(struct work_struct
*work
);
407 extern bool flush_work_sync(struct work_struct
*work
);
408 extern bool cancel_work_sync(struct work_struct
*work
);
410 extern bool flush_delayed_work(struct delayed_work
*dwork
);
411 extern bool flush_delayed_work_sync(struct delayed_work
*work
);
412 extern bool cancel_delayed_work_sync(struct delayed_work
*dwork
);
414 extern void workqueue_set_max_active(struct workqueue_struct
*wq
,
416 extern bool workqueue_congested(unsigned int cpu
, struct workqueue_struct
*wq
);
417 extern unsigned int work_cpu(struct work_struct
*work
);
418 extern unsigned int work_busy(struct work_struct
*work
);
421 * Kill off a pending schedule_delayed_work(). Note that the work callback
422 * function may still be running on return from cancel_delayed_work(), unless
423 * it returns 1 and the work doesn't re-arm itself. Run flush_workqueue() or
424 * cancel_work_sync() to wait on it.
426 static inline bool cancel_delayed_work(struct delayed_work
*work
)
430 ret
= del_timer_sync(&work
->timer
);
432 work_clear_pending(&work
->work
);
437 * Like above, but uses del_timer() instead of del_timer_sync(). This means,
438 * if it returns 0 the timer function may be running and the queueing is in
441 static inline bool __cancel_delayed_work(struct delayed_work
*work
)
445 ret
= del_timer(&work
->timer
);
447 work_clear_pending(&work
->work
);
452 static inline long work_on_cpu(unsigned int cpu
, long (*fn
)(void *), void *arg
)
457 long work_on_cpu(unsigned int cpu
, long (*fn
)(void *), void *arg
);
458 #endif /* CONFIG_SMP */
460 #ifdef CONFIG_FREEZER
461 extern void freeze_workqueues_begin(void);
462 extern bool freeze_workqueues_busy(void);
463 extern void thaw_workqueues(void);
464 #endif /* CONFIG_FREEZER */
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