1 /*
2 * workqueue.h --- work queue handling for Linux.
3 */
4
5 #ifndef _LINUX_WORKQUEUE_H
6 #define _LINUX_WORKQUEUE_H
7
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>
15
16 struct workqueue_struct;
17
18 struct work_struct;
19 typedef void (*work_func_t)(struct work_struct *work);
20 void delayed_work_timer_fn(unsigned long __data);
21
22 /*
23 * The first word is the work queue pointer and the flags rolled into
24 * one
25 */
26 #define work_data_bits(work) ((unsigned long *)(&(work)->data))
27
28 enum {
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 */
36 #else
37 WORK_STRUCT_COLOR_SHIFT = 4, /* color for workqueue flushing */
38 #endif
39
40 WORK_STRUCT_COLOR_BITS = 4,
41
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,
48 #else
49 WORK_STRUCT_STATIC = 0,
50 #endif
51
52 /*
53 * The last color is no color used for works which don't
54 * participate in workqueue flushing.
55 */
56 WORK_NR_COLORS = (1 << WORK_STRUCT_COLOR_BITS) - 1,
57 WORK_NO_COLOR = WORK_NR_COLORS,
58
59 /* not bound to any CPU, prefer the local CPU */
60 WORK_CPU_UNBOUND = NR_CPUS,
61
62 /*
63 * Reserve 7 bits off of pwq pointer w/ debugobjects turned off.
64 * This makes pwqs aligned to 256 bytes and allows 15 workqueue
65 * flush colors.
66 */
67 WORK_STRUCT_FLAG_BITS = WORK_STRUCT_COLOR_SHIFT +
68 WORK_STRUCT_COLOR_BITS,
69
70 /* data contains off-queue information when !WORK_STRUCT_PWQ */
71 WORK_OFFQ_FLAG_BASE = WORK_STRUCT_COLOR_SHIFT,
72
73 __WORK_OFFQ_CANCELING = WORK_OFFQ_FLAG_BASE,
74 WORK_OFFQ_CANCELING = (1 << __WORK_OFFQ_CANCELING),
75
76 /*
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.
80 */
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,
86
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,
91
92 /* bit mask for work_busy() return values */
93 WORK_BUSY_PENDING = 1 << 0,
94 WORK_BUSY_RUNNING = 1 << 1,
95
96 /* maximum string length for set_worker_desc() */
97 WORKER_DESC_LEN = 24,
98 };
99
100 struct work_struct {
101 atomic_long_t data;
102 struct list_head entry;
103 work_func_t func;
104 #ifdef CONFIG_LOCKDEP
105 struct lockdep_map lockdep_map;
106 #endif
107 };
108
109 #define WORK_DATA_INIT() ATOMIC_LONG_INIT(WORK_STRUCT_NO_POOL)
110 #define WORK_DATA_STATIC_INIT() \
111 ATOMIC_LONG_INIT(WORK_STRUCT_NO_POOL | WORK_STRUCT_STATIC)
112
113 struct delayed_work {
114 struct work_struct work;
115 struct timer_list timer;
116
117 /* target workqueue and CPU ->timer uses to queue ->work */
118 struct workqueue_struct *wq;
119 int cpu;
120 };
121
122 /*
123 * A struct for workqueue attributes. This can be used to change
124 * attributes of an unbound workqueue.
125 *
126 * Unlike other fields, ->no_numa isn't a property of a worker_pool. It
127 * only modifies how apply_workqueue_attrs() select pools and thus doesn't
128 * participate in pool hash calculations or equality comparisons.
129 */
130 struct workqueue_attrs {
131 int nice; /* nice level */
132 cpumask_var_t cpumask; /* allowed CPUs */
133 bool no_numa; /* disable NUMA affinity */
134 };
135
to_delayed_work(struct work_struct * work)136 static inline struct delayed_work *to_delayed_work(struct work_struct *work)
137 {
138 return container_of(work, struct delayed_work, work);
139 }
140
141 struct execute_work {
142 struct work_struct work;
143 };
144
145 #ifdef CONFIG_LOCKDEP
146 /*
147 * NB: because we have to copy the lockdep_map, setting _key
148 * here is required, otherwise it could get initialised to the
149 * copy of the lockdep_map!
150 */
151 #define __WORK_INIT_LOCKDEP_MAP(n, k) \
152 .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
153 #else
154 #define __WORK_INIT_LOCKDEP_MAP(n, k)
155 #endif
156
157 #define __WORK_INITIALIZER(n, f) { \
158 .data = WORK_DATA_STATIC_INIT(), \
159 .entry = { &(n).entry, &(n).entry }, \
160 .func = (f), \
161 __WORK_INIT_LOCKDEP_MAP(#n, &(n)) \
162 }
163
164 #define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \
165 .work = __WORK_INITIALIZER((n).work, (f)), \
166 .timer = __TIMER_INITIALIZER(delayed_work_timer_fn, \
167 0, (unsigned long)&(n), \
168 (tflags) | TIMER_IRQSAFE), \
169 }
170
171 #define DECLARE_WORK(n, f) \
172 struct work_struct n = __WORK_INITIALIZER(n, f)
173
174 #define DECLARE_DELAYED_WORK(n, f) \
175 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0)
176
177 #define DECLARE_DEFERRABLE_WORK(n, f) \
178 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, TIMER_DEFERRABLE)
179
180 #ifdef CONFIG_DEBUG_OBJECTS_WORK
181 extern void __init_work(struct work_struct *work, int onstack);
182 extern void destroy_work_on_stack(struct work_struct *work);
183 extern void destroy_delayed_work_on_stack(struct delayed_work *work);
work_static(struct work_struct * work)184 static inline unsigned int work_static(struct work_struct *work)
185 {
186 return *work_data_bits(work) & WORK_STRUCT_STATIC;
187 }
188 #else
__init_work(struct work_struct * work,int onstack)189 static inline void __init_work(struct work_struct *work, int onstack) { }
destroy_work_on_stack(struct work_struct * work)190 static inline void destroy_work_on_stack(struct work_struct *work) { }
destroy_delayed_work_on_stack(struct delayed_work * work)191 static inline void destroy_delayed_work_on_stack(struct delayed_work *work) { }
work_static(struct work_struct * work)192 static inline unsigned int work_static(struct work_struct *work) { return 0; }
193 #endif
194
195 /*
196 * initialize all of a work item in one go
197 *
198 * NOTE! No point in using "atomic_long_set()": using a direct
199 * assignment of the work data initializer allows the compiler
200 * to generate better code.
201 */
202 #ifdef CONFIG_LOCKDEP
203 #define __INIT_WORK(_work, _func, _onstack) \
204 do { \
205 static struct lock_class_key __key; \
206 \
207 __init_work((_work), _onstack); \
208 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
209 lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0); \
210 INIT_LIST_HEAD(&(_work)->entry); \
211 (_work)->func = (_func); \
212 } while (0)
213 #else
214 #define __INIT_WORK(_work, _func, _onstack) \
215 do { \
216 __init_work((_work), _onstack); \
217 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
218 INIT_LIST_HEAD(&(_work)->entry); \
219 (_work)->func = (_func); \
220 } while (0)
221 #endif
222
223 #define INIT_WORK(_work, _func) \
224 __INIT_WORK((_work), (_func), 0)
225
226 #define INIT_WORK_ONSTACK(_work, _func) \
227 __INIT_WORK((_work), (_func), 1)
228
229 #define __INIT_DELAYED_WORK(_work, _func, _tflags) \
230 do { \
231 INIT_WORK(&(_work)->work, (_func)); \
232 __setup_timer(&(_work)->timer, delayed_work_timer_fn, \
233 (unsigned long)(_work), \
234 (_tflags) | TIMER_IRQSAFE); \
235 } while (0)
236
237 #define __INIT_DELAYED_WORK_ONSTACK(_work, _func, _tflags) \
238 do { \
239 INIT_WORK_ONSTACK(&(_work)->work, (_func)); \
240 __setup_timer_on_stack(&(_work)->timer, \
241 delayed_work_timer_fn, \
242 (unsigned long)(_work), \
243 (_tflags) | TIMER_IRQSAFE); \
244 } while (0)
245
246 #define INIT_DELAYED_WORK(_work, _func) \
247 __INIT_DELAYED_WORK(_work, _func, 0)
248
249 #define INIT_DELAYED_WORK_ONSTACK(_work, _func) \
250 __INIT_DELAYED_WORK_ONSTACK(_work, _func, 0)
251
252 #define INIT_DEFERRABLE_WORK(_work, _func) \
253 __INIT_DELAYED_WORK(_work, _func, TIMER_DEFERRABLE)
254
255 #define INIT_DEFERRABLE_WORK_ONSTACK(_work, _func) \
256 __INIT_DELAYED_WORK_ONSTACK(_work, _func, TIMER_DEFERRABLE)
257
258 /**
259 * work_pending - Find out whether a work item is currently pending
260 * @work: The work item in question
261 */
262 #define work_pending(work) \
263 test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
264
265 /**
266 * delayed_work_pending - Find out whether a delayable work item is currently
267 * pending
268 * @w: The work item in question
269 */
270 #define delayed_work_pending(w) \
271 work_pending(&(w)->work)
272
273 /*
274 * Workqueue flags and constants. For details, please refer to
275 * Documentation/workqueue.txt.
276 */
277 enum {
278 WQ_UNBOUND = 1 << 1, /* not bound to any cpu */
279 WQ_FREEZABLE = 1 << 2, /* freeze during suspend */
280 WQ_MEM_RECLAIM = 1 << 3, /* may be used for memory reclaim */
281 WQ_HIGHPRI = 1 << 4, /* high priority */
282 WQ_CPU_INTENSIVE = 1 << 5, /* cpu intensive workqueue */
283 WQ_SYSFS = 1 << 6, /* visible in sysfs, see wq_sysfs_register() */
284
285 /*
286 * Per-cpu workqueues are generally preferred because they tend to
287 * show better performance thanks to cache locality. Per-cpu
288 * workqueues exclude the scheduler from choosing the CPU to
289 * execute the worker threads, which has an unfortunate side effect
290 * of increasing power consumption.
291 *
292 * The scheduler considers a CPU idle if it doesn't have any task
293 * to execute and tries to keep idle cores idle to conserve power;
294 * however, for example, a per-cpu work item scheduled from an
295 * interrupt handler on an idle CPU will force the scheduler to
296 * excute the work item on that CPU breaking the idleness, which in
297 * turn may lead to more scheduling choices which are sub-optimal
298 * in terms of power consumption.
299 *
300 * Workqueues marked with WQ_POWER_EFFICIENT are per-cpu by default
301 * but become unbound if workqueue.power_efficient kernel param is
302 * specified. Per-cpu workqueues which are identified to
303 * contribute significantly to power-consumption are identified and
304 * marked with this flag and enabling the power_efficient mode
305 * leads to noticeable power saving at the cost of small
306 * performance disadvantage.
307 *
308 * http://thread.gmane.org/gmane.linux.kernel/1480396
309 */
310 WQ_POWER_EFFICIENT = 1 << 7,
311
312 __WQ_DRAINING = 1 << 16, /* internal: workqueue is draining */
313 __WQ_ORDERED = 1 << 17, /* internal: workqueue is ordered */
314 __WQ_LEGACY = 1 << 18, /* internal: create*_workqueue() */
315 __WQ_ORDERED_EXPLICIT = 1 << 19, /* internal: alloc_ordered_workqueue() */
316
317 WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */
318 WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */
319 WQ_DFL_ACTIVE = WQ_MAX_ACTIVE / 2,
320 };
321
322 /* unbound wq's aren't per-cpu, scale max_active according to #cpus */
323 #define WQ_UNBOUND_MAX_ACTIVE \
324 max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU)
325
326 /*
327 * System-wide workqueues which are always present.
328 *
329 * system_wq is the one used by schedule[_delayed]_work[_on]().
330 * Multi-CPU multi-threaded. There are users which expect relatively
331 * short queue flush time. Don't queue works which can run for too
332 * long.
333 *
334 * system_highpri_wq is similar to system_wq but for work items which
335 * require WQ_HIGHPRI.
336 *
337 * system_long_wq is similar to system_wq but may host long running
338 * works. Queue flushing might take relatively long.
339 *
340 * system_unbound_wq is unbound workqueue. Workers are not bound to
341 * any specific CPU, not concurrency managed, and all queued works are
342 * executed immediately as long as max_active limit is not reached and
343 * resources are available.
344 *
345 * system_freezable_wq is equivalent to system_wq except that it's
346 * freezable.
347 *
348 * *_power_efficient_wq are inclined towards saving power and converted
349 * into WQ_UNBOUND variants if 'wq_power_efficient' is enabled; otherwise,
350 * they are same as their non-power-efficient counterparts - e.g.
351 * system_power_efficient_wq is identical to system_wq if
352 * 'wq_power_efficient' is disabled. See WQ_POWER_EFFICIENT for more info.
353 */
354 extern struct workqueue_struct *system_wq;
355 extern struct workqueue_struct *system_highpri_wq;
356 extern struct workqueue_struct *system_long_wq;
357 extern struct workqueue_struct *system_unbound_wq;
358 extern struct workqueue_struct *system_freezable_wq;
359 extern struct workqueue_struct *system_power_efficient_wq;
360 extern struct workqueue_struct *system_freezable_power_efficient_wq;
361
362 extern struct workqueue_struct *
363 __alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active,
364 struct lock_class_key *key, const char *lock_name, ...) __printf(1, 6);
365
366 /**
367 * alloc_workqueue - allocate a workqueue
368 * @fmt: printf format for the name of the workqueue
369 * @flags: WQ_* flags
370 * @max_active: max in-flight work items, 0 for default
371 * @args...: args for @fmt
372 *
373 * Allocate a workqueue with the specified parameters. For detailed
374 * information on WQ_* flags, please refer to Documentation/workqueue.txt.
375 *
376 * The __lock_name macro dance is to guarantee that single lock_class_key
377 * doesn't end up with different namesm, which isn't allowed by lockdep.
378 *
379 * RETURNS:
380 * Pointer to the allocated workqueue on success, %NULL on failure.
381 */
382 #ifdef CONFIG_LOCKDEP
383 #define alloc_workqueue(fmt, flags, max_active, args...) \
384 ({ \
385 static struct lock_class_key __key; \
386 const char *__lock_name; \
387 \
388 __lock_name = #fmt#args; \
389 \
390 __alloc_workqueue_key((fmt), (flags), (max_active), \
391 &__key, __lock_name, ##args); \
392 })
393 #else
394 #define alloc_workqueue(fmt, flags, max_active, args...) \
395 __alloc_workqueue_key((fmt), (flags), (max_active), \
396 NULL, NULL, ##args)
397 #endif
398
399 /**
400 * alloc_ordered_workqueue - allocate an ordered workqueue
401 * @fmt: printf format for the name of the workqueue
402 * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
403 * @args...: args for @fmt
404 *
405 * Allocate an ordered workqueue. An ordered workqueue executes at
406 * most one work item at any given time in the queued order. They are
407 * implemented as unbound workqueues with @max_active of one.
408 *
409 * RETURNS:
410 * Pointer to the allocated workqueue on success, %NULL on failure.
411 */
412 #define alloc_ordered_workqueue(fmt, flags, args...) \
413 alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | \
414 __WQ_ORDERED_EXPLICIT | (flags), 1, ##args)
415
416 #define create_workqueue(name) \
417 alloc_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, 1, (name))
418 #define create_freezable_workqueue(name) \
419 alloc_workqueue("%s", __WQ_LEGACY | WQ_FREEZABLE | WQ_UNBOUND | \
420 WQ_MEM_RECLAIM, 1, (name))
421 #define create_singlethread_workqueue(name) \
422 alloc_ordered_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, name)
423
424 extern void destroy_workqueue(struct workqueue_struct *wq);
425
426 struct workqueue_attrs *alloc_workqueue_attrs(gfp_t gfp_mask);
427 void free_workqueue_attrs(struct workqueue_attrs *attrs);
428 int apply_workqueue_attrs(struct workqueue_struct *wq,
429 const struct workqueue_attrs *attrs);
430 int workqueue_set_unbound_cpumask(cpumask_var_t cpumask);
431
432 extern bool queue_work_on(int cpu, struct workqueue_struct *wq,
433 struct work_struct *work);
434 extern bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
435 struct delayed_work *work, unsigned long delay);
436 extern bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq,
437 struct delayed_work *dwork, unsigned long delay);
438
439 extern void flush_workqueue(struct workqueue_struct *wq);
440 extern void drain_workqueue(struct workqueue_struct *wq);
441
442 extern int schedule_on_each_cpu(work_func_t func);
443
444 int execute_in_process_context(work_func_t fn, struct execute_work *);
445
446 extern bool flush_work(struct work_struct *work);
447 extern bool cancel_work(struct work_struct *work);
448 extern bool cancel_work_sync(struct work_struct *work);
449
450 extern bool flush_delayed_work(struct delayed_work *dwork);
451 extern bool cancel_delayed_work(struct delayed_work *dwork);
452 extern bool cancel_delayed_work_sync(struct delayed_work *dwork);
453
454 extern void workqueue_set_max_active(struct workqueue_struct *wq,
455 int max_active);
456 extern struct work_struct *current_work(void);
457 extern bool current_is_workqueue_rescuer(void);
458 extern bool workqueue_congested(int cpu, struct workqueue_struct *wq);
459 extern unsigned int work_busy(struct work_struct *work);
460 extern __printf(1, 2) void set_worker_desc(const char *fmt, ...);
461 extern void print_worker_info(const char *log_lvl, struct task_struct *task);
462 extern void show_workqueue_state(void);
463
464 /**
465 * queue_work - queue work on a workqueue
466 * @wq: workqueue to use
467 * @work: work to queue
468 *
469 * Returns %false if @work was already on a queue, %true otherwise.
470 *
471 * We queue the work to the CPU on which it was submitted, but if the CPU dies
472 * it can be processed by another CPU.
473 */
queue_work(struct workqueue_struct * wq,struct work_struct * work)474 static inline bool queue_work(struct workqueue_struct *wq,
475 struct work_struct *work)
476 {
477 return queue_work_on(WORK_CPU_UNBOUND, wq, work);
478 }
479
480 /**
481 * queue_delayed_work - queue work on a workqueue after delay
482 * @wq: workqueue to use
483 * @dwork: delayable work to queue
484 * @delay: number of jiffies to wait before queueing
485 *
486 * Equivalent to queue_delayed_work_on() but tries to use the local CPU.
487 */
queue_delayed_work(struct workqueue_struct * wq,struct delayed_work * dwork,unsigned long delay)488 static inline bool queue_delayed_work(struct workqueue_struct *wq,
489 struct delayed_work *dwork,
490 unsigned long delay)
491 {
492 return queue_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
493 }
494
495 /**
496 * mod_delayed_work - modify delay of or queue a delayed work
497 * @wq: workqueue to use
498 * @dwork: work to queue
499 * @delay: number of jiffies to wait before queueing
500 *
501 * mod_delayed_work_on() on local CPU.
502 */
mod_delayed_work(struct workqueue_struct * wq,struct delayed_work * dwork,unsigned long delay)503 static inline bool mod_delayed_work(struct workqueue_struct *wq,
504 struct delayed_work *dwork,
505 unsigned long delay)
506 {
507 return mod_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
508 }
509
510 /**
511 * schedule_work_on - put work task on a specific cpu
512 * @cpu: cpu to put the work task on
513 * @work: job to be done
514 *
515 * This puts a job on a specific cpu
516 */
schedule_work_on(int cpu,struct work_struct * work)517 static inline bool schedule_work_on(int cpu, struct work_struct *work)
518 {
519 return queue_work_on(cpu, system_wq, work);
520 }
521
522 /**
523 * schedule_work - put work task in global workqueue
524 * @work: job to be done
525 *
526 * Returns %false if @work was already on the kernel-global workqueue and
527 * %true otherwise.
528 *
529 * This puts a job in the kernel-global workqueue if it was not already
530 * queued and leaves it in the same position on the kernel-global
531 * workqueue otherwise.
532 */
schedule_work(struct work_struct * work)533 static inline bool schedule_work(struct work_struct *work)
534 {
535 return queue_work(system_wq, work);
536 }
537
538 /**
539 * flush_scheduled_work - ensure that any scheduled work has run to completion.
540 *
541 * Forces execution of the kernel-global workqueue and blocks until its
542 * completion.
543 *
544 * Think twice before calling this function! It's very easy to get into
545 * trouble if you don't take great care. Either of the following situations
546 * will lead to deadlock:
547 *
548 * One of the work items currently on the workqueue needs to acquire
549 * a lock held by your code or its caller.
550 *
551 * Your code is running in the context of a work routine.
552 *
553 * They will be detected by lockdep when they occur, but the first might not
554 * occur very often. It depends on what work items are on the workqueue and
555 * what locks they need, which you have no control over.
556 *
557 * In most situations flushing the entire workqueue is overkill; you merely
558 * need to know that a particular work item isn't queued and isn't running.
559 * In such cases you should use cancel_delayed_work_sync() or
560 * cancel_work_sync() instead.
561 */
flush_scheduled_work(void)562 static inline void flush_scheduled_work(void)
563 {
564 flush_workqueue(system_wq);
565 }
566
567 /**
568 * schedule_delayed_work_on - queue work in global workqueue on CPU after delay
569 * @cpu: cpu to use
570 * @dwork: job to be done
571 * @delay: number of jiffies to wait
572 *
573 * After waiting for a given time this puts a job in the kernel-global
574 * workqueue on the specified CPU.
575 */
schedule_delayed_work_on(int cpu,struct delayed_work * dwork,unsigned long delay)576 static inline bool schedule_delayed_work_on(int cpu, struct delayed_work *dwork,
577 unsigned long delay)
578 {
579 return queue_delayed_work_on(cpu, system_wq, dwork, delay);
580 }
581
582 /**
583 * schedule_delayed_work - put work task in global workqueue after delay
584 * @dwork: job to be done
585 * @delay: number of jiffies to wait or 0 for immediate execution
586 *
587 * After waiting for a given time this puts a job in the kernel-global
588 * workqueue.
589 */
schedule_delayed_work(struct delayed_work * dwork,unsigned long delay)590 static inline bool schedule_delayed_work(struct delayed_work *dwork,
591 unsigned long delay)
592 {
593 return queue_delayed_work(system_wq, dwork, delay);
594 }
595
596 /**
597 * keventd_up - is workqueue initialized yet?
598 */
keventd_up(void)599 static inline bool keventd_up(void)
600 {
601 return system_wq != NULL;
602 }
603
604 #ifndef CONFIG_SMP
work_on_cpu(int cpu,long (* fn)(void *),void * arg)605 static inline long work_on_cpu(int cpu, long (*fn)(void *), void *arg)
606 {
607 return fn(arg);
608 }
609 #else
610 long work_on_cpu(int cpu, long (*fn)(void *), void *arg);
611 #endif /* CONFIG_SMP */
612
613 #ifdef CONFIG_FREEZER
614 extern void freeze_workqueues_begin(void);
615 extern bool freeze_workqueues_busy(void);
616 extern void thaw_workqueues(void);
617 #endif /* CONFIG_FREEZER */
618
619 #ifdef CONFIG_SYSFS
620 int workqueue_sysfs_register(struct workqueue_struct *wq);
621 #else /* CONFIG_SYSFS */
workqueue_sysfs_register(struct workqueue_struct * wq)622 static inline int workqueue_sysfs_register(struct workqueue_struct *wq)
623 { return 0; }
624 #endif /* CONFIG_SYSFS */
625
626 #ifdef CONFIG_WQ_WATCHDOG
627 void wq_watchdog_touch(int cpu);
628 #else /* CONFIG_WQ_WATCHDOG */
wq_watchdog_touch(int cpu)629 static inline void wq_watchdog_touch(int cpu) { }
630 #endif /* CONFIG_WQ_WATCHDOG */
631
632 #ifdef CONFIG_SMP
633 int workqueue_prepare_cpu(unsigned int cpu);
634 int workqueue_online_cpu(unsigned int cpu);
635 int workqueue_offline_cpu(unsigned int cpu);
636 #endif
637
638 #endif
639