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>
14 #include <linux/cpumask.h>
16 struct workqueue_struct
;
19 typedef void (*work_func_t
)(struct work_struct
*work
);
20 void delayed_work_timer_fn(unsigned long __data
);
23 * The first word is the work queue pointer and the flags rolled into
26 #define work_data_bits(work) ((unsigned long *)(&(work)->data))
29 WORK_STRUCT_PENDING_BIT
= 0, /* work item is pending execution */
30 WORK_STRUCT_DELAYED_BIT
= 1, /* work item is delayed */
31 WORK_STRUCT_PWQ_BIT
= 2, /* data points to pwq */
32 WORK_STRUCT_LINKED_BIT
= 3, /* next work is linked to this one */
33 #ifdef CONFIG_DEBUG_OBJECTS_WORK
34 WORK_STRUCT_STATIC_BIT
= 4, /* static initializer (debugobjects) */
35 WORK_STRUCT_COLOR_SHIFT
= 5, /* color for workqueue flushing */
37 WORK_STRUCT_COLOR_SHIFT
= 4, /* color for workqueue flushing */
40 WORK_STRUCT_COLOR_BITS
= 4,
42 WORK_STRUCT_PENDING
= 1 << WORK_STRUCT_PENDING_BIT
,
43 WORK_STRUCT_DELAYED
= 1 << WORK_STRUCT_DELAYED_BIT
,
44 WORK_STRUCT_PWQ
= 1 << WORK_STRUCT_PWQ_BIT
,
45 WORK_STRUCT_LINKED
= 1 << WORK_STRUCT_LINKED_BIT
,
46 #ifdef CONFIG_DEBUG_OBJECTS_WORK
47 WORK_STRUCT_STATIC
= 1 << WORK_STRUCT_STATIC_BIT
,
49 WORK_STRUCT_STATIC
= 0,
53 * The last color is no color used for works which don't
54 * participate in workqueue flushing.
56 WORK_NR_COLORS
= (1 << WORK_STRUCT_COLOR_BITS
) - 1,
57 WORK_NO_COLOR
= WORK_NR_COLORS
,
60 WORK_CPU_UNBOUND
= NR_CPUS
,
61 WORK_CPU_END
= NR_CPUS
+ 1,
64 * Reserve 7 bits off of pwq pointer w/ debugobjects turned off.
65 * This makes pwqs aligned to 256 bytes and allows 15 workqueue
68 WORK_STRUCT_FLAG_BITS
= WORK_STRUCT_COLOR_SHIFT
+
69 WORK_STRUCT_COLOR_BITS
,
71 /* data contains off-queue information when !WORK_STRUCT_PWQ */
72 WORK_OFFQ_FLAG_BASE
= WORK_STRUCT_COLOR_SHIFT
,
74 WORK_OFFQ_CANCELING
= (1 << WORK_OFFQ_FLAG_BASE
),
77 * When a work item is off queue, its high bits point to the last
78 * pool it was on. Cap at 31 bits and use the highest number to
79 * indicate that no pool is associated.
81 WORK_OFFQ_FLAG_BITS
= 1,
82 WORK_OFFQ_POOL_SHIFT
= WORK_OFFQ_FLAG_BASE
+ WORK_OFFQ_FLAG_BITS
,
83 WORK_OFFQ_LEFT
= BITS_PER_LONG
- WORK_OFFQ_POOL_SHIFT
,
84 WORK_OFFQ_POOL_BITS
= WORK_OFFQ_LEFT
<= 31 ? WORK_OFFQ_LEFT
: 31,
85 WORK_OFFQ_POOL_NONE
= (1LU << WORK_OFFQ_POOL_BITS
) - 1,
87 /* convenience constants */
88 WORK_STRUCT_FLAG_MASK
= (1UL << WORK_STRUCT_FLAG_BITS
) - 1,
89 WORK_STRUCT_WQ_DATA_MASK
= ~WORK_STRUCT_FLAG_MASK
,
90 WORK_STRUCT_NO_POOL
= (unsigned long)WORK_OFFQ_POOL_NONE
<< WORK_OFFQ_POOL_SHIFT
,
92 /* bit mask for work_busy() return values */
93 WORK_BUSY_PENDING
= 1 << 0,
94 WORK_BUSY_RUNNING
= 1 << 1,
99 struct list_head entry
;
101 #ifdef CONFIG_LOCKDEP
102 struct lockdep_map lockdep_map
;
106 #define WORK_DATA_INIT() ATOMIC_LONG_INIT(WORK_STRUCT_NO_POOL)
107 #define WORK_DATA_STATIC_INIT() \
108 ATOMIC_LONG_INIT(WORK_STRUCT_NO_POOL | WORK_STRUCT_STATIC)
110 struct delayed_work
{
111 struct work_struct work
;
112 struct timer_list timer
;
114 /* target workqueue and CPU ->timer uses to queue ->work */
115 struct workqueue_struct
*wq
;
120 * A struct for workqueue attributes. This can be used to change
121 * attributes of an unbound workqueue.
123 * Unlike other fields, ->no_numa isn't a property of a worker_pool. It
124 * only modifies how apply_workqueue_attrs() select pools and thus doesn't
125 * participate in pool hash calculations or equality comparisons.
127 struct workqueue_attrs
{
128 int nice
; /* nice level */
129 cpumask_var_t cpumask
; /* allowed CPUs */
130 bool no_numa
; /* disable NUMA affinity */
133 static inline struct delayed_work
*to_delayed_work(struct work_struct
*work
)
135 return container_of(work
, struct delayed_work
, work
);
138 struct execute_work
{
139 struct work_struct work
;
142 #ifdef CONFIG_LOCKDEP
144 * NB: because we have to copy the lockdep_map, setting _key
145 * here is required, otherwise it could get initialised to the
146 * copy of the lockdep_map!
148 #define __WORK_INIT_LOCKDEP_MAP(n, k) \
149 .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
151 #define __WORK_INIT_LOCKDEP_MAP(n, k)
154 #define __WORK_INITIALIZER(n, f) { \
155 .data = WORK_DATA_STATIC_INIT(), \
156 .entry = { &(n).entry, &(n).entry }, \
158 __WORK_INIT_LOCKDEP_MAP(#n, &(n)) \
161 #define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \
162 .work = __WORK_INITIALIZER((n).work, (f)), \
163 .timer = __TIMER_INITIALIZER(delayed_work_timer_fn, \
164 0, (unsigned long)&(n), \
165 (tflags) | TIMER_IRQSAFE), \
168 #define DECLARE_WORK(n, f) \
169 struct work_struct n = __WORK_INITIALIZER(n, f)
171 #define DECLARE_DELAYED_WORK(n, f) \
172 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0)
174 #define DECLARE_DEFERRABLE_WORK(n, f) \
175 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, TIMER_DEFERRABLE)
178 * initialize a work item's function pointer
180 #define PREPARE_WORK(_work, _func) \
182 (_work)->func = (_func); \
185 #define PREPARE_DELAYED_WORK(_work, _func) \
186 PREPARE_WORK(&(_work)->work, (_func))
188 #ifdef CONFIG_DEBUG_OBJECTS_WORK
189 extern void __init_work(struct work_struct
*work
, int onstack
);
190 extern void destroy_work_on_stack(struct work_struct
*work
);
191 static inline unsigned int work_static(struct work_struct
*work
)
193 return *work_data_bits(work
) & WORK_STRUCT_STATIC
;
196 static inline void __init_work(struct work_struct
*work
, int onstack
) { }
197 static inline void destroy_work_on_stack(struct work_struct
*work
) { }
198 static inline unsigned int work_static(struct work_struct
*work
) { return 0; }
202 * initialize all of a work item in one go
204 * NOTE! No point in using "atomic_long_set()": using a direct
205 * assignment of the work data initializer allows the compiler
206 * to generate better code.
208 #ifdef CONFIG_LOCKDEP
209 #define __INIT_WORK(_work, _func, _onstack) \
211 static struct lock_class_key __key; \
213 __init_work((_work), _onstack); \
214 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
215 lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0); \
216 INIT_LIST_HEAD(&(_work)->entry); \
217 PREPARE_WORK((_work), (_func)); \
220 #define __INIT_WORK(_work, _func, _onstack) \
222 __init_work((_work), _onstack); \
223 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
224 INIT_LIST_HEAD(&(_work)->entry); \
225 PREPARE_WORK((_work), (_func)); \
229 #define INIT_WORK(_work, _func) \
231 __INIT_WORK((_work), (_func), 0); \
234 #define INIT_WORK_ONSTACK(_work, _func) \
236 __INIT_WORK((_work), (_func), 1); \
239 #define __INIT_DELAYED_WORK(_work, _func, _tflags) \
241 INIT_WORK(&(_work)->work, (_func)); \
242 __setup_timer(&(_work)->timer, delayed_work_timer_fn, \
243 (unsigned long)(_work), \
244 (_tflags) | TIMER_IRQSAFE); \
247 #define __INIT_DELAYED_WORK_ONSTACK(_work, _func, _tflags) \
249 INIT_WORK_ONSTACK(&(_work)->work, (_func)); \
250 __setup_timer_on_stack(&(_work)->timer, \
251 delayed_work_timer_fn, \
252 (unsigned long)(_work), \
253 (_tflags) | TIMER_IRQSAFE); \
256 #define INIT_DELAYED_WORK(_work, _func) \
257 __INIT_DELAYED_WORK(_work, _func, 0)
259 #define INIT_DELAYED_WORK_ONSTACK(_work, _func) \
260 __INIT_DELAYED_WORK_ONSTACK(_work, _func, 0)
262 #define INIT_DEFERRABLE_WORK(_work, _func) \
263 __INIT_DELAYED_WORK(_work, _func, TIMER_DEFERRABLE)
265 #define INIT_DEFERRABLE_WORK_ONSTACK(_work, _func) \
266 __INIT_DELAYED_WORK_ONSTACK(_work, _func, TIMER_DEFERRABLE)
269 * work_pending - Find out whether a work item is currently pending
270 * @work: The work item in question
272 #define work_pending(work) \
273 test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
276 * delayed_work_pending - Find out whether a delayable work item is currently
278 * @work: The work item in question
280 #define delayed_work_pending(w) \
281 work_pending(&(w)->work)
284 * work_clear_pending - for internal use only, mark a work item as not pending
285 * @work: The work item in question
287 #define work_clear_pending(work) \
288 clear_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
291 * Workqueue flags and constants. For details, please refer to
292 * Documentation/workqueue.txt.
295 WQ_NON_REENTRANT
= 1 << 0, /* guarantee non-reentrance */
296 WQ_UNBOUND
= 1 << 1, /* not bound to any cpu */
297 WQ_FREEZABLE
= 1 << 2, /* freeze during suspend */
298 WQ_MEM_RECLAIM
= 1 << 3, /* may be used for memory reclaim */
299 WQ_HIGHPRI
= 1 << 4, /* high priority */
300 WQ_CPU_INTENSIVE
= 1 << 5, /* cpu instensive workqueue */
301 WQ_SYSFS
= 1 << 6, /* visible in sysfs, see wq_sysfs_register() */
303 __WQ_DRAINING
= 1 << 16, /* internal: workqueue is draining */
304 __WQ_ORDERED
= 1 << 17, /* internal: workqueue is ordered */
306 WQ_MAX_ACTIVE
= 512, /* I like 512, better ideas? */
307 WQ_MAX_UNBOUND_PER_CPU
= 4, /* 4 * #cpus for unbound wq */
308 WQ_DFL_ACTIVE
= WQ_MAX_ACTIVE
/ 2,
311 /* unbound wq's aren't per-cpu, scale max_active according to #cpus */
312 #define WQ_UNBOUND_MAX_ACTIVE \
313 max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU)
316 * System-wide workqueues which are always present.
318 * system_wq is the one used by schedule[_delayed]_work[_on]().
319 * Multi-CPU multi-threaded. There are users which expect relatively
320 * short queue flush time. Don't queue works which can run for too
323 * system_long_wq is similar to system_wq but may host long running
324 * works. Queue flushing might take relatively long.
326 * system_unbound_wq is unbound workqueue. Workers are not bound to
327 * any specific CPU, not concurrency managed, and all queued works are
328 * executed immediately as long as max_active limit is not reached and
329 * resources are available.
331 * system_freezable_wq is equivalent to system_wq except that it's
334 extern struct workqueue_struct
*system_wq
;
335 extern struct workqueue_struct
*system_long_wq
;
336 extern struct workqueue_struct
*system_unbound_wq
;
337 extern struct workqueue_struct
*system_freezable_wq
;
339 static inline struct workqueue_struct
* __deprecated
__system_nrt_wq(void)
344 static inline struct workqueue_struct
* __deprecated
__system_nrt_freezable_wq(void)
346 return system_freezable_wq
;
349 /* equivlalent to system_wq and system_freezable_wq, deprecated */
350 #define system_nrt_wq __system_nrt_wq()
351 #define system_nrt_freezable_wq __system_nrt_freezable_wq()
353 extern struct workqueue_struct
*
354 __alloc_workqueue_key(const char *fmt
, unsigned int flags
, int max_active
,
355 struct lock_class_key
*key
, const char *lock_name
, ...) __printf(1, 6);
358 * alloc_workqueue - allocate a workqueue
359 * @fmt: printf format for the name of the workqueue
361 * @max_active: max in-flight work items, 0 for default
362 * @args: args for @fmt
364 * Allocate a workqueue with the specified parameters. For detailed
365 * information on WQ_* flags, please refer to Documentation/workqueue.txt.
367 * The __lock_name macro dance is to guarantee that single lock_class_key
368 * doesn't end up with different namesm, which isn't allowed by lockdep.
371 * Pointer to the allocated workqueue on success, %NULL on failure.
373 #ifdef CONFIG_LOCKDEP
374 #define alloc_workqueue(fmt, flags, max_active, args...) \
376 static struct lock_class_key __key; \
377 const char *__lock_name; \
379 if (__builtin_constant_p(fmt)) \
380 __lock_name = (fmt); \
382 __lock_name = #fmt; \
384 __alloc_workqueue_key((fmt), (flags), (max_active), \
385 &__key, __lock_name, ##args); \
388 #define alloc_workqueue(fmt, flags, max_active, args...) \
389 __alloc_workqueue_key((fmt), (flags), (max_active), \
394 * alloc_ordered_workqueue - allocate an ordered workqueue
395 * @fmt: printf format for the name of the workqueue
396 * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
397 * @args: args for @fmt
399 * Allocate an ordered workqueue. An ordered workqueue executes at
400 * most one work item at any given time in the queued order. They are
401 * implemented as unbound workqueues with @max_active of one.
404 * Pointer to the allocated workqueue on success, %NULL on failure.
406 #define alloc_ordered_workqueue(fmt, flags, args...) \
407 alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | (flags), 1, ##args)
409 #define create_workqueue(name) \
410 alloc_workqueue((name), WQ_MEM_RECLAIM, 1)
411 #define create_freezable_workqueue(name) \
412 alloc_workqueue((name), WQ_FREEZABLE | WQ_UNBOUND | WQ_MEM_RECLAIM, 1)
413 #define create_singlethread_workqueue(name) \
414 alloc_workqueue((name), WQ_UNBOUND | WQ_MEM_RECLAIM, 1)
416 extern void destroy_workqueue(struct workqueue_struct
*wq
);
418 struct workqueue_attrs
*alloc_workqueue_attrs(gfp_t gfp_mask
);
419 void free_workqueue_attrs(struct workqueue_attrs
*attrs
);
420 int apply_workqueue_attrs(struct workqueue_struct
*wq
,
421 const struct workqueue_attrs
*attrs
);
423 extern bool queue_work_on(int cpu
, struct workqueue_struct
*wq
,
424 struct work_struct
*work
);
425 extern bool queue_delayed_work_on(int cpu
, struct workqueue_struct
*wq
,
426 struct delayed_work
*work
, unsigned long delay
);
427 extern bool mod_delayed_work_on(int cpu
, struct workqueue_struct
*wq
,
428 struct delayed_work
*dwork
, unsigned long delay
);
430 extern void flush_workqueue(struct workqueue_struct
*wq
);
431 extern void drain_workqueue(struct workqueue_struct
*wq
);
432 extern void flush_scheduled_work(void);
434 extern int schedule_on_each_cpu(work_func_t func
);
436 int execute_in_process_context(work_func_t fn
, struct execute_work
*);
438 extern bool flush_work(struct work_struct
*work
);
439 extern bool cancel_work_sync(struct work_struct
*work
);
441 extern bool flush_delayed_work(struct delayed_work
*dwork
);
442 extern bool cancel_delayed_work(struct delayed_work
*dwork
);
443 extern bool cancel_delayed_work_sync(struct delayed_work
*dwork
);
445 extern void workqueue_set_max_active(struct workqueue_struct
*wq
,
447 extern bool current_is_workqueue_rescuer(void);
448 extern bool workqueue_congested(int cpu
, struct workqueue_struct
*wq
);
449 extern unsigned int work_busy(struct work_struct
*work
);
452 * queue_work - queue work on a workqueue
453 * @wq: workqueue to use
454 * @work: work to queue
456 * Returns %false if @work was already on a queue, %true otherwise.
458 * We queue the work to the CPU on which it was submitted, but if the CPU dies
459 * it can be processed by another CPU.
461 static inline bool queue_work(struct workqueue_struct
*wq
,
462 struct work_struct
*work
)
464 return queue_work_on(WORK_CPU_UNBOUND
, wq
, work
);
468 * queue_delayed_work - queue work on a workqueue after delay
469 * @wq: workqueue to use
470 * @dwork: delayable work to queue
471 * @delay: number of jiffies to wait before queueing
473 * Equivalent to queue_delayed_work_on() but tries to use the local CPU.
475 static inline bool queue_delayed_work(struct workqueue_struct
*wq
,
476 struct delayed_work
*dwork
,
479 return queue_delayed_work_on(WORK_CPU_UNBOUND
, wq
, dwork
, delay
);
483 * mod_delayed_work - modify delay of or queue a delayed work
484 * @wq: workqueue to use
485 * @dwork: work to queue
486 * @delay: number of jiffies to wait before queueing
488 * mod_delayed_work_on() on local CPU.
490 static inline bool mod_delayed_work(struct workqueue_struct
*wq
,
491 struct delayed_work
*dwork
,
494 return mod_delayed_work_on(WORK_CPU_UNBOUND
, wq
, dwork
, delay
);
498 * schedule_work_on - put work task on a specific cpu
499 * @cpu: cpu to put the work task on
500 * @work: job to be done
502 * This puts a job on a specific cpu
504 static inline bool schedule_work_on(int cpu
, struct work_struct
*work
)
506 return queue_work_on(cpu
, system_wq
, work
);
510 * schedule_work - put work task in global workqueue
511 * @work: job to be done
513 * Returns %false if @work was already on the kernel-global workqueue and
516 * This puts a job in the kernel-global workqueue if it was not already
517 * queued and leaves it in the same position on the kernel-global
518 * workqueue otherwise.
520 static inline bool schedule_work(struct work_struct
*work
)
522 return queue_work(system_wq
, work
);
526 * schedule_delayed_work_on - queue work in global workqueue on CPU after delay
528 * @dwork: job to be done
529 * @delay: number of jiffies to wait
531 * After waiting for a given time this puts a job in the kernel-global
532 * workqueue on the specified CPU.
534 static inline bool schedule_delayed_work_on(int cpu
, struct delayed_work
*dwork
,
537 return queue_delayed_work_on(cpu
, system_wq
, dwork
, delay
);
541 * schedule_delayed_work - put work task in global workqueue after delay
542 * @dwork: job to be done
543 * @delay: number of jiffies to wait or 0 for immediate execution
545 * After waiting for a given time this puts a job in the kernel-global
548 static inline bool schedule_delayed_work(struct delayed_work
*dwork
,
551 return queue_delayed_work(system_wq
, dwork
, delay
);
555 * keventd_up - is workqueue initialized yet?
557 static inline bool keventd_up(void)
559 return system_wq
!= NULL
;
563 * Like above, but uses del_timer() instead of del_timer_sync(). This means,
564 * if it returns 0 the timer function may be running and the queueing is in
567 static inline bool __deprecated
__cancel_delayed_work(struct delayed_work
*work
)
571 ret
= del_timer(&work
->timer
);
573 work_clear_pending(&work
->work
);
577 /* used to be different but now identical to flush_work(), deprecated */
578 static inline bool __deprecated
flush_work_sync(struct work_struct
*work
)
580 return flush_work(work
);
583 /* used to be different but now identical to flush_delayed_work(), deprecated */
584 static inline bool __deprecated
flush_delayed_work_sync(struct delayed_work
*dwork
)
586 return flush_delayed_work(dwork
);
590 static inline long work_on_cpu(int cpu
, long (*fn
)(void *), void *arg
)
595 long work_on_cpu(int cpu
, long (*fn
)(void *), void *arg
);
596 #endif /* CONFIG_SMP */
598 #ifdef CONFIG_FREEZER
599 extern void freeze_workqueues_begin(void);
600 extern bool freeze_workqueues_busy(void);
601 extern void thaw_workqueues(void);
602 #endif /* CONFIG_FREEZER */
605 int workqueue_sysfs_register(struct workqueue_struct
*wq
);
606 #else /* CONFIG_SYSFS */
607 static inline int workqueue_sysfs_register(struct workqueue_struct
*wq
)
609 #endif /* CONFIG_SYSFS */
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