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 struct workqueue_attrs {
124 int nice; /* nice level */
125 cpumask_var_t cpumask; /* allowed CPUs */
128 static inline struct delayed_work *to_delayed_work(struct work_struct *work)
130 return container_of(work, struct delayed_work, work);
133 struct execute_work {
134 struct work_struct work;
137 #ifdef CONFIG_LOCKDEP
139 * NB: because we have to copy the lockdep_map, setting _key
140 * here is required, otherwise it could get initialised to the
141 * copy of the lockdep_map!
143 #define __WORK_INIT_LOCKDEP_MAP(n, k) \
144 .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
146 #define __WORK_INIT_LOCKDEP_MAP(n, k)
149 #define __WORK_INITIALIZER(n, f) { \
150 .data = WORK_DATA_STATIC_INIT(), \
151 .entry = { &(n).entry, &(n).entry }, \
153 __WORK_INIT_LOCKDEP_MAP(#n, &(n)) \
156 #define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \
157 .work = __WORK_INITIALIZER((n).work, (f)), \
158 .timer = __TIMER_INITIALIZER(delayed_work_timer_fn, \
159 0, (unsigned long)&(n), \
160 (tflags) | TIMER_IRQSAFE), \
163 #define DECLARE_WORK(n, f) \
164 struct work_struct n = __WORK_INITIALIZER(n, f)
166 #define DECLARE_DELAYED_WORK(n, f) \
167 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0)
169 #define DECLARE_DEFERRABLE_WORK(n, f) \
170 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, TIMER_DEFERRABLE)
173 * initialize a work item's function pointer
175 #define PREPARE_WORK(_work, _func) \
177 (_work)->func = (_func); \
180 #define PREPARE_DELAYED_WORK(_work, _func) \
181 PREPARE_WORK(&(_work)->work, (_func))
183 #ifdef CONFIG_DEBUG_OBJECTS_WORK
184 extern void __init_work(struct work_struct *work, int onstack);
185 extern void destroy_work_on_stack(struct work_struct *work);
186 static inline unsigned int work_static(struct work_struct *work)
188 return *work_data_bits(work) & WORK_STRUCT_STATIC;
191 static inline void __init_work(struct work_struct *work, int onstack) { }
192 static inline void destroy_work_on_stack(struct work_struct *work) { }
193 static inline unsigned int work_static(struct work_struct *work) { return 0; }
197 * initialize all of a work item in one go
199 * NOTE! No point in using "atomic_long_set()": using a direct
200 * assignment of the work data initializer allows the compiler
201 * to generate better code.
203 #ifdef CONFIG_LOCKDEP
204 #define __INIT_WORK(_work, _func, _onstack) \
206 static struct lock_class_key __key; \
208 __init_work((_work), _onstack); \
209 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
210 lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0); \
211 INIT_LIST_HEAD(&(_work)->entry); \
212 PREPARE_WORK((_work), (_func)); \
215 #define __INIT_WORK(_work, _func, _onstack) \
217 __init_work((_work), _onstack); \
218 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
219 INIT_LIST_HEAD(&(_work)->entry); \
220 PREPARE_WORK((_work), (_func)); \
224 #define INIT_WORK(_work, _func) \
226 __INIT_WORK((_work), (_func), 0); \
229 #define INIT_WORK_ONSTACK(_work, _func) \
231 __INIT_WORK((_work), (_func), 1); \
234 #define __INIT_DELAYED_WORK(_work, _func, _tflags) \
236 INIT_WORK(&(_work)->work, (_func)); \
237 __setup_timer(&(_work)->timer, delayed_work_timer_fn, \
238 (unsigned long)(_work), \
239 (_tflags) | TIMER_IRQSAFE); \
242 #define __INIT_DELAYED_WORK_ONSTACK(_work, _func, _tflags) \
244 INIT_WORK_ONSTACK(&(_work)->work, (_func)); \
245 __setup_timer_on_stack(&(_work)->timer, \
246 delayed_work_timer_fn, \
247 (unsigned long)(_work), \
248 (_tflags) | TIMER_IRQSAFE); \
251 #define INIT_DELAYED_WORK(_work, _func) \
252 __INIT_DELAYED_WORK(_work, _func, 0)
254 #define INIT_DELAYED_WORK_ONSTACK(_work, _func) \
255 __INIT_DELAYED_WORK_ONSTACK(_work, _func, 0)
257 #define INIT_DEFERRABLE_WORK(_work, _func) \
258 __INIT_DELAYED_WORK(_work, _func, TIMER_DEFERRABLE)
260 #define INIT_DEFERRABLE_WORK_ONSTACK(_work, _func) \
261 __INIT_DELAYED_WORK_ONSTACK(_work, _func, TIMER_DEFERRABLE)
264 * work_pending - Find out whether a work item is currently pending
265 * @work: The work item in question
267 #define work_pending(work) \
268 test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
271 * delayed_work_pending - Find out whether a delayable work item is currently
273 * @work: The work item in question
275 #define delayed_work_pending(w) \
276 work_pending(&(w)->work)
279 * work_clear_pending - for internal use only, mark a work item as not pending
280 * @work: The work item in question
282 #define work_clear_pending(work) \
283 clear_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
286 * Workqueue flags and constants. For details, please refer to
287 * Documentation/workqueue.txt.
290 WQ_NON_REENTRANT = 1 << 0, /* guarantee non-reentrance */
291 WQ_UNBOUND = 1 << 1, /* not bound to any cpu */
292 WQ_FREEZABLE = 1 << 2, /* freeze during suspend */
293 WQ_MEM_RECLAIM = 1 << 3, /* may be used for memory reclaim */
294 WQ_HIGHPRI = 1 << 4, /* high priority */
295 WQ_CPU_INTENSIVE = 1 << 5, /* cpu instensive workqueue */
297 WQ_DRAINING = 1 << 6, /* internal: workqueue is draining */
298 WQ_RESCUER = 1 << 7, /* internal: workqueue has rescuer */
300 WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */
301 WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */
302 WQ_DFL_ACTIVE = WQ_MAX_ACTIVE / 2,
305 /* unbound wq's aren't per-cpu, scale max_active according to #cpus */
306 #define WQ_UNBOUND_MAX_ACTIVE \
307 max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU)
310 * System-wide workqueues which are always present.
312 * system_wq is the one used by schedule[_delayed]_work[_on]().
313 * Multi-CPU multi-threaded. There are users which expect relatively
314 * short queue flush time. Don't queue works which can run for too
317 * system_long_wq is similar to system_wq but may host long running
318 * works. Queue flushing might take relatively long.
320 * system_unbound_wq is unbound workqueue. Workers are not bound to
321 * any specific CPU, not concurrency managed, and all queued works are
322 * executed immediately as long as max_active limit is not reached and
323 * resources are available.
325 * system_freezable_wq is equivalent to system_wq except that it's
328 extern struct workqueue_struct *system_wq;
329 extern struct workqueue_struct *system_long_wq;
330 extern struct workqueue_struct *system_unbound_wq;
331 extern struct workqueue_struct *system_freezable_wq;
333 static inline struct workqueue_struct * __deprecated __system_nrt_wq(void)
338 static inline struct workqueue_struct * __deprecated __system_nrt_freezable_wq(void)
340 return system_freezable_wq;
343 /* equivlalent to system_wq and system_freezable_wq, deprecated */
344 #define system_nrt_wq __system_nrt_wq()
345 #define system_nrt_freezable_wq __system_nrt_freezable_wq()
347 extern struct workqueue_struct *
348 __alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active,
349 struct lock_class_key *key, const char *lock_name, ...) __printf(1, 6);
352 * alloc_workqueue - allocate a workqueue
353 * @fmt: printf format for the name of the workqueue
355 * @max_active: max in-flight work items, 0 for default
356 * @args: args for @fmt
358 * Allocate a workqueue with the specified parameters. For detailed
359 * information on WQ_* flags, please refer to Documentation/workqueue.txt.
361 * The __lock_name macro dance is to guarantee that single lock_class_key
362 * doesn't end up with different namesm, which isn't allowed by lockdep.
365 * Pointer to the allocated workqueue on success, %NULL on failure.
367 #ifdef CONFIG_LOCKDEP
368 #define alloc_workqueue(fmt, flags, max_active, args...) \
370 static struct lock_class_key __key; \
371 const char *__lock_name; \
373 if (__builtin_constant_p(fmt)) \
374 __lock_name = (fmt); \
376 __lock_name = #fmt; \
378 __alloc_workqueue_key((fmt), (flags), (max_active), \
379 &__key, __lock_name, ##args); \
382 #define alloc_workqueue(fmt, flags, max_active, args...) \
383 __alloc_workqueue_key((fmt), (flags), (max_active), \
388 * alloc_ordered_workqueue - allocate an ordered workqueue
389 * @fmt: printf format for the name of the workqueue
390 * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
391 * @args: args for @fmt
393 * Allocate an ordered workqueue. An ordered workqueue executes at
394 * most one work item at any given time in the queued order. They are
395 * implemented as unbound workqueues with @max_active of one.
398 * Pointer to the allocated workqueue on success, %NULL on failure.
400 #define alloc_ordered_workqueue(fmt, flags, args...) \
401 alloc_workqueue(fmt, WQ_UNBOUND | (flags), 1, ##args)
403 #define create_workqueue(name) \
404 alloc_workqueue((name), WQ_MEM_RECLAIM, 1)
405 #define create_freezable_workqueue(name) \
406 alloc_workqueue((name), WQ_FREEZABLE | WQ_UNBOUND | WQ_MEM_RECLAIM, 1)
407 #define create_singlethread_workqueue(name) \
408 alloc_workqueue((name), WQ_UNBOUND | WQ_MEM_RECLAIM, 1)
410 extern void destroy_workqueue(struct workqueue_struct *wq);
412 struct workqueue_attrs *alloc_workqueue_attrs(gfp_t gfp_mask);
413 void free_workqueue_attrs(struct workqueue_attrs *attrs);
415 extern bool queue_work_on(int cpu, struct workqueue_struct *wq,
416 struct work_struct *work);
417 extern bool queue_work(struct workqueue_struct *wq, struct work_struct *work);
418 extern bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
419 struct delayed_work *work, unsigned long delay);
420 extern bool queue_delayed_work(struct workqueue_struct *wq,
421 struct delayed_work *work, unsigned long delay);
422 extern bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq,
423 struct delayed_work *dwork, unsigned long delay);
424 extern bool mod_delayed_work(struct workqueue_struct *wq,
425 struct delayed_work *dwork, unsigned long delay);
427 extern void flush_workqueue(struct workqueue_struct *wq);
428 extern void drain_workqueue(struct workqueue_struct *wq);
429 extern void flush_scheduled_work(void);
431 extern bool schedule_work_on(int cpu, struct work_struct *work);
432 extern bool schedule_work(struct work_struct *work);
433 extern bool schedule_delayed_work_on(int cpu, struct delayed_work *work,
434 unsigned long delay);
435 extern bool schedule_delayed_work(struct delayed_work *work,
436 unsigned long delay);
437 extern int schedule_on_each_cpu(work_func_t func);
438 extern int keventd_up(void);
440 int execute_in_process_context(work_func_t fn, struct execute_work *);
442 extern bool flush_work(struct work_struct *work);
443 extern bool cancel_work_sync(struct work_struct *work);
445 extern bool flush_delayed_work(struct delayed_work *dwork);
446 extern bool cancel_delayed_work(struct delayed_work *dwork);
447 extern bool cancel_delayed_work_sync(struct delayed_work *dwork);
449 extern void workqueue_set_max_active(struct workqueue_struct *wq,
451 extern bool workqueue_congested(int cpu, struct workqueue_struct *wq);
452 extern unsigned int work_busy(struct work_struct *work);
455 * Like above, but uses del_timer() instead of del_timer_sync(). This means,
456 * if it returns 0 the timer function may be running and the queueing is in
459 static inline bool __deprecated __cancel_delayed_work(struct delayed_work *work)
463 ret = del_timer(&work->timer);
465 work_clear_pending(&work->work);
469 /* used to be different but now identical to flush_work(), deprecated */
470 static inline bool __deprecated flush_work_sync(struct work_struct *work)
472 return flush_work(work);
475 /* used to be different but now identical to flush_delayed_work(), deprecated */
476 static inline bool __deprecated flush_delayed_work_sync(struct delayed_work *dwork)
478 return flush_delayed_work(dwork);
482 static inline long work_on_cpu(int cpu, long (*fn)(void *), void *arg)
487 long work_on_cpu(int cpu, long (*fn)(void *), void *arg);
488 #endif /* CONFIG_SMP */
490 #ifdef CONFIG_FREEZER
491 extern void freeze_workqueues_begin(void);
492 extern bool freeze_workqueues_busy(void);
493 extern void thaw_workqueues(void);
494 #endif /* CONFIG_FREEZER */