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 <asm/atomic.h>
15 struct workqueue_struct;
18 typedef void (*work_func_t)(struct work_struct *work);
21 * The first word is the work queue pointer and the flags rolled into
24 #define work_data_bits(work) ((unsigned long *)(&(work)->data))
27 WORK_STRUCT_PENDING_BIT = 0, /* work item is pending execution */
28 WORK_STRUCT_LINKED_BIT = 1, /* next work is linked to this one */
29 #ifdef CONFIG_DEBUG_OBJECTS_WORK
30 WORK_STRUCT_STATIC_BIT = 2, /* static initializer (debugobjects) */
31 WORK_STRUCT_COLOR_SHIFT = 3, /* color for workqueue flushing */
33 WORK_STRUCT_COLOR_SHIFT = 2, /* color for workqueue flushing */
36 WORK_STRUCT_COLOR_BITS = 4,
38 WORK_STRUCT_PENDING = 1 << WORK_STRUCT_PENDING_BIT,
39 WORK_STRUCT_LINKED = 1 << WORK_STRUCT_LINKED_BIT,
40 #ifdef CONFIG_DEBUG_OBJECTS_WORK
41 WORK_STRUCT_STATIC = 1 << WORK_STRUCT_STATIC_BIT,
43 WORK_STRUCT_STATIC = 0,
47 * The last color is no color used for works which don't
48 * participate in workqueue flushing.
50 WORK_NR_COLORS = (1 << WORK_STRUCT_COLOR_BITS) - 1,
51 WORK_NO_COLOR = WORK_NR_COLORS,
54 * Reserve 6 bits off of cwq pointer w/ debugobjects turned
55 * off. This makes cwqs aligned to 64 bytes which isn't too
56 * excessive while allowing 15 workqueue flush colors.
58 WORK_STRUCT_FLAG_BITS = WORK_STRUCT_COLOR_SHIFT +
59 WORK_STRUCT_COLOR_BITS,
61 WORK_STRUCT_FLAG_MASK = (1UL << WORK_STRUCT_FLAG_BITS) - 1,
62 WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK,
63 WORK_STRUCT_NO_CPU = NR_CPUS << WORK_STRUCT_FLAG_BITS,
68 struct list_head entry;
71 struct lockdep_map lockdep_map;
75 #define WORK_DATA_INIT() ATOMIC_LONG_INIT(WORK_STRUCT_NO_CPU)
76 #define WORK_DATA_STATIC_INIT() \
77 ATOMIC_LONG_INIT(WORK_STRUCT_NO_CPU | WORK_STRUCT_STATIC)
80 struct work_struct work;
81 struct timer_list timer;
84 static inline struct delayed_work *to_delayed_work(struct work_struct *work)
86 return container_of(work, struct delayed_work, work);
90 struct work_struct work;
95 * NB: because we have to copy the lockdep_map, setting _key
96 * here is required, otherwise it could get initialised to the
97 * copy of the lockdep_map!
99 #define __WORK_INIT_LOCKDEP_MAP(n, k) \
100 .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
102 #define __WORK_INIT_LOCKDEP_MAP(n, k)
105 #define __WORK_INITIALIZER(n, f) { \
106 .data = WORK_DATA_STATIC_INIT(), \
107 .entry = { &(n).entry, &(n).entry }, \
109 __WORK_INIT_LOCKDEP_MAP(#n, &(n)) \
112 #define __DELAYED_WORK_INITIALIZER(n, f) { \
113 .work = __WORK_INITIALIZER((n).work, (f)), \
114 .timer = TIMER_INITIALIZER(NULL, 0, 0), \
117 #define DECLARE_WORK(n, f) \
118 struct work_struct n = __WORK_INITIALIZER(n, f)
120 #define DECLARE_DELAYED_WORK(n, f) \
121 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f)
124 * initialize a work item's function pointer
126 #define PREPARE_WORK(_work, _func) \
128 (_work)->func = (_func); \
131 #define PREPARE_DELAYED_WORK(_work, _func) \
132 PREPARE_WORK(&(_work)->work, (_func))
134 #ifdef CONFIG_DEBUG_OBJECTS_WORK
135 extern void __init_work(struct work_struct *work, int onstack);
136 extern void destroy_work_on_stack(struct work_struct *work);
137 static inline unsigned int work_static(struct work_struct *work)
139 return *work_data_bits(work) & WORK_STRUCT_STATIC;
142 static inline void __init_work(struct work_struct *work, int onstack) { }
143 static inline void destroy_work_on_stack(struct work_struct *work) { }
144 static inline unsigned int work_static(struct work_struct *work) { return 0; }
148 * initialize all of a work item in one go
150 * NOTE! No point in using "atomic_long_set()": using a direct
151 * assignment of the work data initializer allows the compiler
152 * to generate better code.
154 #ifdef CONFIG_LOCKDEP
155 #define __INIT_WORK(_work, _func, _onstack) \
157 static struct lock_class_key __key; \
159 __init_work((_work), _onstack); \
160 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
161 lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0);\
162 INIT_LIST_HEAD(&(_work)->entry); \
163 PREPARE_WORK((_work), (_func)); \
166 #define __INIT_WORK(_work, _func, _onstack) \
168 __init_work((_work), _onstack); \
169 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
170 INIT_LIST_HEAD(&(_work)->entry); \
171 PREPARE_WORK((_work), (_func)); \
175 #define INIT_WORK(_work, _func) \
177 __INIT_WORK((_work), (_func), 0); \
180 #define INIT_WORK_ON_STACK(_work, _func) \
182 __INIT_WORK((_work), (_func), 1); \
185 #define INIT_DELAYED_WORK(_work, _func) \
187 INIT_WORK(&(_work)->work, (_func)); \
188 init_timer(&(_work)->timer); \
191 #define INIT_DELAYED_WORK_ON_STACK(_work, _func) \
193 INIT_WORK_ON_STACK(&(_work)->work, (_func)); \
194 init_timer_on_stack(&(_work)->timer); \
197 #define INIT_DELAYED_WORK_DEFERRABLE(_work, _func) \
199 INIT_WORK(&(_work)->work, (_func)); \
200 init_timer_deferrable(&(_work)->timer); \
204 * work_pending - Find out whether a work item is currently pending
205 * @work: The work item in question
207 #define work_pending(work) \
208 test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
211 * delayed_work_pending - Find out whether a delayable work item is currently
213 * @work: The work item in question
215 #define delayed_work_pending(w) \
216 work_pending(&(w)->work)
219 * work_clear_pending - for internal use only, mark a work item as not pending
220 * @work: The work item in question
222 #define work_clear_pending(work) \
223 clear_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
226 WQ_FREEZEABLE = 1 << 0, /* freeze during suspend */
227 WQ_SINGLE_CPU = 1 << 1, /* only single cpu at a time */
228 WQ_NON_REENTRANT = 1 << 2, /* guarantee non-reentrance */
229 WQ_RESCUER = 1 << 3, /* has an rescue worker */
231 WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */
232 WQ_DFL_ACTIVE = WQ_MAX_ACTIVE / 2,
236 * System-wide workqueues which are always present.
238 * system_wq is the one used by schedule[_delayed]_work[_on]().
239 * Multi-CPU multi-threaded. There are users which expect relatively
240 * short queue flush time. Don't queue works which can run for too
243 * system_long_wq is similar to system_wq but may host long running
244 * works. Queue flushing might take relatively long.
246 * system_nrt_wq is non-reentrant and guarantees that any given work
247 * item is never executed in parallel by multiple CPUs. Queue
248 * flushing might take relatively long.
250 extern struct workqueue_struct *system_wq;
251 extern struct workqueue_struct *system_long_wq;
252 extern struct workqueue_struct *system_nrt_wq;
254 extern struct workqueue_struct *
255 __alloc_workqueue_key(const char *name, unsigned int flags, int max_active,
256 struct lock_class_key *key, const char *lock_name);
258 #ifdef CONFIG_LOCKDEP
259 #define alloc_workqueue(name, flags, max_active) \
261 static struct lock_class_key __key; \
262 const char *__lock_name; \
264 if (__builtin_constant_p(name)) \
265 __lock_name = (name); \
267 __lock_name = #name; \
269 __alloc_workqueue_key((name), (flags), (max_active), \
270 &__key, __lock_name); \
273 #define alloc_workqueue(name, flags, max_active) \
274 __alloc_workqueue_key((name), (flags), (max_active), NULL, NULL)
277 #define create_workqueue(name) \
278 alloc_workqueue((name), WQ_RESCUER, 1)
279 #define create_freezeable_workqueue(name) \
280 alloc_workqueue((name), WQ_FREEZEABLE | WQ_SINGLE_CPU | WQ_RESCUER, 1)
281 #define create_singlethread_workqueue(name) \
282 alloc_workqueue((name), WQ_SINGLE_CPU | WQ_RESCUER, 1)
284 extern void destroy_workqueue(struct workqueue_struct *wq);
286 extern int queue_work(struct workqueue_struct *wq, struct work_struct *work);
287 extern int queue_work_on(int cpu, struct workqueue_struct *wq,
288 struct work_struct *work);
289 extern int queue_delayed_work(struct workqueue_struct *wq,
290 struct delayed_work *work, unsigned long delay);
291 extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
292 struct delayed_work *work, unsigned long delay);
294 extern void flush_workqueue(struct workqueue_struct *wq);
295 extern void flush_scheduled_work(void);
296 extern void flush_delayed_work(struct delayed_work *work);
298 extern int schedule_work(struct work_struct *work);
299 extern int schedule_work_on(int cpu, struct work_struct *work);
300 extern int schedule_delayed_work(struct delayed_work *work, unsigned long delay);
301 extern int schedule_delayed_work_on(int cpu, struct delayed_work *work,
302 unsigned long delay);
303 extern int schedule_on_each_cpu(work_func_t func);
304 extern int keventd_up(void);
306 extern void init_workqueues(void);
307 int execute_in_process_context(work_func_t fn, struct execute_work *);
309 extern int flush_work(struct work_struct *work);
311 extern int cancel_work_sync(struct work_struct *work);
314 * Kill off a pending schedule_delayed_work(). Note that the work callback
315 * function may still be running on return from cancel_delayed_work(), unless
316 * it returns 1 and the work doesn't re-arm itself. Run flush_workqueue() or
317 * cancel_work_sync() to wait on it.
319 static inline int cancel_delayed_work(struct delayed_work *work)
323 ret = del_timer_sync(&work->timer);
325 work_clear_pending(&work->work);
330 * Like above, but uses del_timer() instead of del_timer_sync(). This means,
331 * if it returns 0 the timer function may be running and the queueing is in
334 static inline int __cancel_delayed_work(struct delayed_work *work)
338 ret = del_timer(&work->timer);
340 work_clear_pending(&work->work);
344 extern int cancel_delayed_work_sync(struct delayed_work *work);
346 /* Obsolete. use cancel_delayed_work_sync() */
348 void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq,
349 struct delayed_work *work)
351 cancel_delayed_work_sync(work);
354 /* Obsolete. use cancel_delayed_work_sync() */
356 void cancel_rearming_delayed_work(struct delayed_work *work)
358 cancel_delayed_work_sync(work);
362 static inline long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg)
367 long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg);
368 #endif /* CONFIG_SMP */
370 #ifdef CONFIG_FREEZER
371 extern void freeze_workqueues_begin(void);
372 extern bool freeze_workqueues_busy(void);
373 extern void thaw_workqueues(void);
374 #endif /* CONFIG_FREEZER */