Commit | Line | Data |
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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | /* |
3 | * workqueue.h --- work queue handling for Linux. | |
4 | */ | |
5 | ||
6 | #ifndef _LINUX_WORKQUEUE_H | |
7 | #define _LINUX_WORKQUEUE_H | |
8 | ||
9 | #include <linux/timer.h> | |
10 | #include <linux/linkage.h> | |
11 | #include <linux/bitops.h> | |
4e6045f1 | 12 | #include <linux/lockdep.h> |
7a22ad75 | 13 | #include <linux/threads.h> |
60063497 | 14 | #include <linux/atomic.h> |
7a4e344c | 15 | #include <linux/cpumask.h> |
05f0fe6b | 16 | #include <linux/rcupdate.h> |
1da177e4 LT |
17 | |
18 | struct workqueue_struct; | |
19 | ||
65f27f38 DH |
20 | struct work_struct; |
21 | typedef void (*work_func_t)(struct work_struct *work); | |
8c20feb6 | 22 | void delayed_work_timer_fn(struct timer_list *t); |
6bb49e59 | 23 | |
a08727ba LT |
24 | /* |
25 | * The first word is the work queue pointer and the flags rolled into | |
26 | * one | |
27 | */ | |
28 | #define work_data_bits(work) ((unsigned long *)(&(work)->data)) | |
29 | ||
22df02bb TH |
30 | enum { |
31 | WORK_STRUCT_PENDING_BIT = 0, /* work item is pending execution */ | |
f97a4a1a | 32 | WORK_STRUCT_INACTIVE_BIT= 1, /* work item is inactive */ |
112202d9 | 33 | WORK_STRUCT_PWQ_BIT = 2, /* data points to pwq */ |
8a2e8e5d | 34 | WORK_STRUCT_LINKED_BIT = 3, /* next work is linked to this one */ |
22df02bb | 35 | #ifdef CONFIG_DEBUG_OBJECTS_WORK |
8a2e8e5d TH |
36 | WORK_STRUCT_STATIC_BIT = 4, /* static initializer (debugobjects) */ |
37 | WORK_STRUCT_COLOR_SHIFT = 5, /* color for workqueue flushing */ | |
0f900049 | 38 | #else |
8a2e8e5d | 39 | WORK_STRUCT_COLOR_SHIFT = 4, /* color for workqueue flushing */ |
22df02bb TH |
40 | #endif |
41 | ||
73f53c4a TH |
42 | WORK_STRUCT_COLOR_BITS = 4, |
43 | ||
22df02bb | 44 | WORK_STRUCT_PENDING = 1 << WORK_STRUCT_PENDING_BIT, |
f97a4a1a | 45 | WORK_STRUCT_INACTIVE = 1 << WORK_STRUCT_INACTIVE_BIT, |
112202d9 | 46 | WORK_STRUCT_PWQ = 1 << WORK_STRUCT_PWQ_BIT, |
affee4b2 | 47 | WORK_STRUCT_LINKED = 1 << WORK_STRUCT_LINKED_BIT, |
22df02bb TH |
48 | #ifdef CONFIG_DEBUG_OBJECTS_WORK |
49 | WORK_STRUCT_STATIC = 1 << WORK_STRUCT_STATIC_BIT, | |
50 | #else | |
51 | WORK_STRUCT_STATIC = 0, | |
52 | #endif | |
53 | ||
bdb0a654 | 54 | WORK_NR_COLORS = (1 << WORK_STRUCT_COLOR_BITS), |
73f53c4a | 55 | |
79bc251f | 56 | /* not bound to any CPU, prefer the local CPU */ |
f3421797 | 57 | WORK_CPU_UNBOUND = NR_CPUS, |
bdbc5dd7 | 58 | |
73f53c4a | 59 | /* |
c39ba6b3 | 60 | * Reserve 8 bits off of pwq pointer w/ debugobjects turned off. |
bdb0a654 | 61 | * This makes pwqs aligned to 256 bytes and allows 16 workqueue |
112202d9 | 62 | * flush colors. |
73f53c4a TH |
63 | */ |
64 | WORK_STRUCT_FLAG_BITS = WORK_STRUCT_COLOR_SHIFT + | |
65 | WORK_STRUCT_COLOR_BITS, | |
66 | ||
112202d9 | 67 | /* data contains off-queue information when !WORK_STRUCT_PWQ */ |
45d9550a | 68 | WORK_OFFQ_FLAG_BASE = WORK_STRUCT_COLOR_SHIFT, |
bbb68dfa | 69 | |
8603e1b3 TH |
70 | __WORK_OFFQ_CANCELING = WORK_OFFQ_FLAG_BASE, |
71 | WORK_OFFQ_CANCELING = (1 << __WORK_OFFQ_CANCELING), | |
bbb68dfa | 72 | |
715b06b8 TH |
73 | /* |
74 | * When a work item is off queue, its high bits point to the last | |
7c3eed5c TH |
75 | * pool it was on. Cap at 31 bits and use the highest number to |
76 | * indicate that no pool is associated. | |
715b06b8 | 77 | */ |
bbb68dfa | 78 | WORK_OFFQ_FLAG_BITS = 1, |
7c3eed5c TH |
79 | WORK_OFFQ_POOL_SHIFT = WORK_OFFQ_FLAG_BASE + WORK_OFFQ_FLAG_BITS, |
80 | WORK_OFFQ_LEFT = BITS_PER_LONG - WORK_OFFQ_POOL_SHIFT, | |
81 | WORK_OFFQ_POOL_BITS = WORK_OFFQ_LEFT <= 31 ? WORK_OFFQ_LEFT : 31, | |
82 | WORK_OFFQ_POOL_NONE = (1LU << WORK_OFFQ_POOL_BITS) - 1, | |
b5490077 TH |
83 | |
84 | /* convenience constants */ | |
0f900049 | 85 | WORK_STRUCT_FLAG_MASK = (1UL << WORK_STRUCT_FLAG_BITS) - 1, |
22df02bb | 86 | WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK, |
7c3eed5c | 87 | WORK_STRUCT_NO_POOL = (unsigned long)WORK_OFFQ_POOL_NONE << WORK_OFFQ_POOL_SHIFT, |
dcd989cb TH |
88 | |
89 | /* bit mask for work_busy() return values */ | |
90 | WORK_BUSY_PENDING = 1 << 0, | |
91 | WORK_BUSY_RUNNING = 1 << 1, | |
3d1cb205 TH |
92 | |
93 | /* maximum string length for set_worker_desc() */ | |
94 | WORKER_DESC_LEN = 24, | |
22df02bb TH |
95 | }; |
96 | ||
1da177e4 | 97 | struct work_struct { |
a08727ba | 98 | atomic_long_t data; |
1da177e4 | 99 | struct list_head entry; |
6bb49e59 | 100 | work_func_t func; |
4e6045f1 JB |
101 | #ifdef CONFIG_LOCKDEP |
102 | struct lockdep_map lockdep_map; | |
103 | #endif | |
52bad64d DH |
104 | }; |
105 | ||
a45463cb | 106 | #define WORK_DATA_INIT() ATOMIC_LONG_INIT((unsigned long)WORK_STRUCT_NO_POOL) |
7a22ad75 | 107 | #define WORK_DATA_STATIC_INIT() \ |
a45463cb | 108 | ATOMIC_LONG_INIT((unsigned long)(WORK_STRUCT_NO_POOL | WORK_STRUCT_STATIC)) |
a08727ba | 109 | |
52bad64d DH |
110 | struct delayed_work { |
111 | struct work_struct work; | |
1da177e4 | 112 | struct timer_list timer; |
60c057bc LJ |
113 | |
114 | /* target workqueue and CPU ->timer uses to queue ->work */ | |
115 | struct workqueue_struct *wq; | |
1265057f | 116 | int cpu; |
1da177e4 LT |
117 | }; |
118 | ||
05f0fe6b TH |
119 | struct rcu_work { |
120 | struct work_struct work; | |
121 | struct rcu_head rcu; | |
122 | ||
123 | /* target workqueue ->rcu uses to queue ->work */ | |
124 | struct workqueue_struct *wq; | |
125 | }; | |
126 | ||
42412c3a SF |
127 | /** |
128 | * struct workqueue_attrs - A struct for workqueue attributes. | |
d55262c4 | 129 | * |
42412c3a | 130 | * This can be used to change attributes of an unbound workqueue. |
7a4e344c TH |
131 | */ |
132 | struct workqueue_attrs { | |
42412c3a SF |
133 | /** |
134 | * @nice: nice level | |
135 | */ | |
136 | int nice; | |
137 | ||
138 | /** | |
139 | * @cpumask: allowed CPUs | |
140 | */ | |
141 | cpumask_var_t cpumask; | |
142 | ||
143 | /** | |
144 | * @no_numa: disable NUMA affinity | |
145 | * | |
146 | * Unlike other fields, ``no_numa`` isn't a property of a worker_pool. It | |
147 | * only modifies how :c:func:`apply_workqueue_attrs` select pools and thus | |
148 | * doesn't participate in pool hash calculations or equality comparisons. | |
149 | */ | |
150 | bool no_numa; | |
7a4e344c TH |
151 | }; |
152 | ||
bf6aede7 JD |
153 | static inline struct delayed_work *to_delayed_work(struct work_struct *work) |
154 | { | |
155 | return container_of(work, struct delayed_work, work); | |
156 | } | |
157 | ||
05f0fe6b TH |
158 | static inline struct rcu_work *to_rcu_work(struct work_struct *work) |
159 | { | |
160 | return container_of(work, struct rcu_work, work); | |
161 | } | |
162 | ||
1fa44eca JB |
163 | struct execute_work { |
164 | struct work_struct work; | |
165 | }; | |
166 | ||
4e6045f1 JB |
167 | #ifdef CONFIG_LOCKDEP |
168 | /* | |
169 | * NB: because we have to copy the lockdep_map, setting _key | |
170 | * here is required, otherwise it could get initialised to the | |
171 | * copy of the lockdep_map! | |
172 | */ | |
173 | #define __WORK_INIT_LOCKDEP_MAP(n, k) \ | |
174 | .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k), | |
175 | #else | |
176 | #define __WORK_INIT_LOCKDEP_MAP(n, k) | |
177 | #endif | |
178 | ||
ee64e7f6 TH |
179 | #define __WORK_INITIALIZER(n, f) { \ |
180 | .data = WORK_DATA_STATIC_INIT(), \ | |
181 | .entry = { &(n).entry, &(n).entry }, \ | |
182 | .func = (f), \ | |
183 | __WORK_INIT_LOCKDEP_MAP(#n, &(n)) \ | |
65f27f38 DH |
184 | } |
185 | ||
f991b318 | 186 | #define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \ |
ee64e7f6 | 187 | .work = __WORK_INITIALIZER((n).work, (f)), \ |
841b86f3 | 188 | .timer = __TIMER_INITIALIZER(delayed_work_timer_fn,\ |
e0aecdd8 | 189 | (tflags) | TIMER_IRQSAFE), \ |
dd6414b5 PC |
190 | } |
191 | ||
ee64e7f6 | 192 | #define DECLARE_WORK(n, f) \ |
65f27f38 DH |
193 | struct work_struct n = __WORK_INITIALIZER(n, f) |
194 | ||
ee64e7f6 | 195 | #define DECLARE_DELAYED_WORK(n, f) \ |
f991b318 | 196 | struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0) |
65f27f38 | 197 | |
203b42f7 | 198 | #define DECLARE_DEFERRABLE_WORK(n, f) \ |
f991b318 | 199 | struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, TIMER_DEFERRABLE) |
dd6414b5 | 200 | |
dc186ad7 TG |
201 | #ifdef CONFIG_DEBUG_OBJECTS_WORK |
202 | extern void __init_work(struct work_struct *work, int onstack); | |
203 | extern void destroy_work_on_stack(struct work_struct *work); | |
ea2e64f2 | 204 | extern void destroy_delayed_work_on_stack(struct delayed_work *work); |
4690c4ab TH |
205 | static inline unsigned int work_static(struct work_struct *work) |
206 | { | |
22df02bb | 207 | return *work_data_bits(work) & WORK_STRUCT_STATIC; |
4690c4ab | 208 | } |
dc186ad7 TG |
209 | #else |
210 | static inline void __init_work(struct work_struct *work, int onstack) { } | |
211 | static inline void destroy_work_on_stack(struct work_struct *work) { } | |
ea2e64f2 | 212 | static inline void destroy_delayed_work_on_stack(struct delayed_work *work) { } |
4690c4ab | 213 | static inline unsigned int work_static(struct work_struct *work) { return 0; } |
dc186ad7 TG |
214 | #endif |
215 | ||
1da177e4 | 216 | /* |
52bad64d | 217 | * initialize all of a work item in one go |
a08727ba | 218 | * |
b9049df5 | 219 | * NOTE! No point in using "atomic_long_set()": using a direct |
a08727ba LT |
220 | * assignment of the work data initializer allows the compiler |
221 | * to generate better code. | |
1da177e4 | 222 | */ |
4e6045f1 | 223 | #ifdef CONFIG_LOCKDEP |
dc186ad7 | 224 | #define __INIT_WORK(_work, _func, _onstack) \ |
65f27f38 | 225 | do { \ |
4e6045f1 JB |
226 | static struct lock_class_key __key; \ |
227 | \ | |
dc186ad7 | 228 | __init_work((_work), _onstack); \ |
23b2e599 | 229 | (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \ |
fd1a5b04 | 230 | lockdep_init_map(&(_work)->lockdep_map, "(work_completion)"#_work, &__key, 0); \ |
65f27f38 | 231 | INIT_LIST_HEAD(&(_work)->entry); \ |
f073f922 | 232 | (_work)->func = (_func); \ |
65f27f38 | 233 | } while (0) |
4e6045f1 | 234 | #else |
dc186ad7 | 235 | #define __INIT_WORK(_work, _func, _onstack) \ |
4e6045f1 | 236 | do { \ |
dc186ad7 | 237 | __init_work((_work), _onstack); \ |
4e6045f1 JB |
238 | (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \ |
239 | INIT_LIST_HEAD(&(_work)->entry); \ | |
f073f922 | 240 | (_work)->func = (_func); \ |
4e6045f1 JB |
241 | } while (0) |
242 | #endif | |
65f27f38 | 243 | |
ee64e7f6 | 244 | #define INIT_WORK(_work, _func) \ |
9da7dae9 | 245 | __INIT_WORK((_work), (_func), 0) |
dc186ad7 | 246 | |
ee64e7f6 | 247 | #define INIT_WORK_ONSTACK(_work, _func) \ |
9da7dae9 | 248 | __INIT_WORK((_work), (_func), 1) |
dc186ad7 | 249 | |
f991b318 | 250 | #define __INIT_DELAYED_WORK(_work, _func, _tflags) \ |
ee64e7f6 TH |
251 | do { \ |
252 | INIT_WORK(&(_work)->work, (_func)); \ | |
919b250f KC |
253 | __init_timer(&(_work)->timer, \ |
254 | delayed_work_timer_fn, \ | |
255 | (_tflags) | TIMER_IRQSAFE); \ | |
52bad64d DH |
256 | } while (0) |
257 | ||
f991b318 | 258 | #define __INIT_DELAYED_WORK_ONSTACK(_work, _func, _tflags) \ |
ee64e7f6 TH |
259 | do { \ |
260 | INIT_WORK_ONSTACK(&(_work)->work, (_func)); \ | |
919b250f KC |
261 | __init_timer_on_stack(&(_work)->timer, \ |
262 | delayed_work_timer_fn, \ | |
263 | (_tflags) | TIMER_IRQSAFE); \ | |
6d612b0f PZ |
264 | } while (0) |
265 | ||
f991b318 TH |
266 | #define INIT_DELAYED_WORK(_work, _func) \ |
267 | __INIT_DELAYED_WORK(_work, _func, 0) | |
268 | ||
269 | #define INIT_DELAYED_WORK_ONSTACK(_work, _func) \ | |
270 | __INIT_DELAYED_WORK_ONSTACK(_work, _func, 0) | |
271 | ||
203b42f7 | 272 | #define INIT_DEFERRABLE_WORK(_work, _func) \ |
f991b318 TH |
273 | __INIT_DELAYED_WORK(_work, _func, TIMER_DEFERRABLE) |
274 | ||
275 | #define INIT_DEFERRABLE_WORK_ONSTACK(_work, _func) \ | |
276 | __INIT_DELAYED_WORK_ONSTACK(_work, _func, TIMER_DEFERRABLE) | |
28287033 | 277 | |
05f0fe6b TH |
278 | #define INIT_RCU_WORK(_work, _func) \ |
279 | INIT_WORK(&(_work)->work, (_func)) | |
280 | ||
281 | #define INIT_RCU_WORK_ONSTACK(_work, _func) \ | |
282 | INIT_WORK_ONSTACK(&(_work)->work, (_func)) | |
283 | ||
365970a1 DH |
284 | /** |
285 | * work_pending - Find out whether a work item is currently pending | |
286 | * @work: The work item in question | |
287 | */ | |
288 | #define work_pending(work) \ | |
22df02bb | 289 | test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work)) |
365970a1 DH |
290 | |
291 | /** | |
292 | * delayed_work_pending - Find out whether a delayable work item is currently | |
293 | * pending | |
355c0663 | 294 | * @w: The work item in question |
365970a1 | 295 | */ |
0221872a LT |
296 | #define delayed_work_pending(w) \ |
297 | work_pending(&(w)->work) | |
365970a1 | 298 | |
c54fce6e TH |
299 | /* |
300 | * Workqueue flags and constants. For details, please refer to | |
42412c3a | 301 | * Documentation/core-api/workqueue.rst. |
c54fce6e | 302 | */ |
97e37d7b | 303 | enum { |
c7fc77f7 | 304 | WQ_UNBOUND = 1 << 1, /* not bound to any cpu */ |
58a69cb4 | 305 | WQ_FREEZABLE = 1 << 2, /* freeze during suspend */ |
6370a6ad | 306 | WQ_MEM_RECLAIM = 1 << 3, /* may be used for memory reclaim */ |
649027d7 | 307 | WQ_HIGHPRI = 1 << 4, /* high priority */ |
41f50094 | 308 | WQ_CPU_INTENSIVE = 1 << 5, /* cpu intensive workqueue */ |
93e86295 | 309 | WQ_SYSFS = 1 << 6, /* visible in sysfs, see workqueue_sysfs_register() */ |
b71ab8c2 | 310 | |
cee22a15 VK |
311 | /* |
312 | * Per-cpu workqueues are generally preferred because they tend to | |
313 | * show better performance thanks to cache locality. Per-cpu | |
314 | * workqueues exclude the scheduler from choosing the CPU to | |
315 | * execute the worker threads, which has an unfortunate side effect | |
316 | * of increasing power consumption. | |
317 | * | |
318 | * The scheduler considers a CPU idle if it doesn't have any task | |
319 | * to execute and tries to keep idle cores idle to conserve power; | |
320 | * however, for example, a per-cpu work item scheduled from an | |
321 | * interrupt handler on an idle CPU will force the scheduler to | |
67dc8325 | 322 | * execute the work item on that CPU breaking the idleness, which in |
cee22a15 VK |
323 | * turn may lead to more scheduling choices which are sub-optimal |
324 | * in terms of power consumption. | |
325 | * | |
326 | * Workqueues marked with WQ_POWER_EFFICIENT are per-cpu by default | |
327 | * but become unbound if workqueue.power_efficient kernel param is | |
328 | * specified. Per-cpu workqueues which are identified to | |
329 | * contribute significantly to power-consumption are identified and | |
330 | * marked with this flag and enabling the power_efficient mode | |
331 | * leads to noticeable power saving at the cost of small | |
332 | * performance disadvantage. | |
333 | * | |
334 | * http://thread.gmane.org/gmane.linux.kernel/1480396 | |
335 | */ | |
336 | WQ_POWER_EFFICIENT = 1 << 7, | |
337 | ||
618b01eb | 338 | __WQ_DRAINING = 1 << 16, /* internal: workqueue is draining */ |
8719dcea | 339 | __WQ_ORDERED = 1 << 17, /* internal: workqueue is ordered */ |
23d11a58 | 340 | __WQ_LEGACY = 1 << 18, /* internal: create*_workqueue() */ |
fbf1c41f | 341 | __WQ_ORDERED_EXPLICIT = 1 << 19, /* internal: alloc_ordered_workqueue() */ |
e41e704b | 342 | |
b71ab8c2 | 343 | WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */ |
f3421797 | 344 | WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */ |
b71ab8c2 | 345 | WQ_DFL_ACTIVE = WQ_MAX_ACTIVE / 2, |
97e37d7b | 346 | }; |
52bad64d | 347 | |
f3421797 TH |
348 | /* unbound wq's aren't per-cpu, scale max_active according to #cpus */ |
349 | #define WQ_UNBOUND_MAX_ACTIVE \ | |
350 | max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU) | |
65f27f38 | 351 | |
d320c038 TH |
352 | /* |
353 | * System-wide workqueues which are always present. | |
354 | * | |
355 | * system_wq is the one used by schedule[_delayed]_work[_on](). | |
356 | * Multi-CPU multi-threaded. There are users which expect relatively | |
357 | * short queue flush time. Don't queue works which can run for too | |
358 | * long. | |
359 | * | |
73e43544 LJ |
360 | * system_highpri_wq is similar to system_wq but for work items which |
361 | * require WQ_HIGHPRI. | |
362 | * | |
d320c038 TH |
363 | * system_long_wq is similar to system_wq but may host long running |
364 | * works. Queue flushing might take relatively long. | |
365 | * | |
f3421797 TH |
366 | * system_unbound_wq is unbound workqueue. Workers are not bound to |
367 | * any specific CPU, not concurrency managed, and all queued works are | |
368 | * executed immediately as long as max_active limit is not reached and | |
369 | * resources are available. | |
4149efb2 | 370 | * |
24d51add TH |
371 | * system_freezable_wq is equivalent to system_wq except that it's |
372 | * freezable. | |
0668106c VK |
373 | * |
374 | * *_power_efficient_wq are inclined towards saving power and converted | |
375 | * into WQ_UNBOUND variants if 'wq_power_efficient' is enabled; otherwise, | |
376 | * they are same as their non-power-efficient counterparts - e.g. | |
377 | * system_power_efficient_wq is identical to system_wq if | |
378 | * 'wq_power_efficient' is disabled. See WQ_POWER_EFFICIENT for more info. | |
d320c038 TH |
379 | */ |
380 | extern struct workqueue_struct *system_wq; | |
73e43544 | 381 | extern struct workqueue_struct *system_highpri_wq; |
d320c038 | 382 | extern struct workqueue_struct *system_long_wq; |
f3421797 | 383 | extern struct workqueue_struct *system_unbound_wq; |
24d51add | 384 | extern struct workqueue_struct *system_freezable_wq; |
0668106c VK |
385 | extern struct workqueue_struct *system_power_efficient_wq; |
386 | extern struct workqueue_struct *system_freezable_power_efficient_wq; | |
ae930e0f | 387 | |
b196be89 TH |
388 | /** |
389 | * alloc_workqueue - allocate a workqueue | |
390 | * @fmt: printf format for the name of the workqueue | |
391 | * @flags: WQ_* flags | |
392 | * @max_active: max in-flight work items, 0 for default | |
669de8bd | 393 | * remaining args: args for @fmt |
b196be89 TH |
394 | * |
395 | * Allocate a workqueue with the specified parameters. For detailed | |
42412c3a SF |
396 | * information on WQ_* flags, please refer to |
397 | * Documentation/core-api/workqueue.rst. | |
b196be89 | 398 | * |
b196be89 TH |
399 | * RETURNS: |
400 | * Pointer to the allocated workqueue on success, %NULL on failure. | |
401 | */ | |
80f0a1f9 REB |
402 | __printf(1, 4) struct workqueue_struct * |
403 | alloc_workqueue(const char *fmt, unsigned int flags, int max_active, ...); | |
4e6045f1 | 404 | |
81dcaf65 TH |
405 | /** |
406 | * alloc_ordered_workqueue - allocate an ordered workqueue | |
b196be89 | 407 | * @fmt: printf format for the name of the workqueue |
58a69cb4 | 408 | * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful) |
8bee9dd9 | 409 | * @args: args for @fmt |
81dcaf65 TH |
410 | * |
411 | * Allocate an ordered workqueue. An ordered workqueue executes at | |
412 | * most one work item at any given time in the queued order. They are | |
413 | * implemented as unbound workqueues with @max_active of one. | |
414 | * | |
415 | * RETURNS: | |
416 | * Pointer to the allocated workqueue on success, %NULL on failure. | |
417 | */ | |
ee64e7f6 | 418 | #define alloc_ordered_workqueue(fmt, flags, args...) \ |
0a94efb5 TH |
419 | alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | \ |
420 | __WQ_ORDERED_EXPLICIT | (flags), 1, ##args) | |
81dcaf65 | 421 | |
ee64e7f6 | 422 | #define create_workqueue(name) \ |
23d11a58 | 423 | alloc_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, 1, (name)) |
ee64e7f6 | 424 | #define create_freezable_workqueue(name) \ |
23d11a58 TH |
425 | alloc_workqueue("%s", __WQ_LEGACY | WQ_FREEZABLE | WQ_UNBOUND | \ |
426 | WQ_MEM_RECLAIM, 1, (name)) | |
ee64e7f6 | 427 | #define create_singlethread_workqueue(name) \ |
23d11a58 | 428 | alloc_ordered_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, name) |
1da177e4 LT |
429 | |
430 | extern void destroy_workqueue(struct workqueue_struct *wq); | |
431 | ||
513c98d0 DJ |
432 | struct workqueue_attrs *alloc_workqueue_attrs(void); |
433 | void free_workqueue_attrs(struct workqueue_attrs *attrs); | |
434 | int apply_workqueue_attrs(struct workqueue_struct *wq, | |
435 | const struct workqueue_attrs *attrs); | |
042f7df1 | 436 | int workqueue_set_unbound_cpumask(cpumask_var_t cpumask); |
7a4e344c | 437 | |
d4283e93 | 438 | extern bool queue_work_on(int cpu, struct workqueue_struct *wq, |
c1a220e7 | 439 | struct work_struct *work); |
8204e0c1 AD |
440 | extern bool queue_work_node(int node, struct workqueue_struct *wq, |
441 | struct work_struct *work); | |
d4283e93 | 442 | extern bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq, |
28e53bdd | 443 | struct delayed_work *work, unsigned long delay); |
8376fe22 TH |
444 | extern bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq, |
445 | struct delayed_work *dwork, unsigned long delay); | |
05f0fe6b | 446 | extern bool queue_rcu_work(struct workqueue_struct *wq, struct rcu_work *rwork); |
28e53bdd | 447 | |
c4f135d6 | 448 | extern void __flush_workqueue(struct workqueue_struct *wq); |
9c5a2ba7 | 449 | extern void drain_workqueue(struct workqueue_struct *wq); |
1da177e4 | 450 | |
65f27f38 | 451 | extern int schedule_on_each_cpu(work_func_t func); |
1da177e4 | 452 | |
65f27f38 | 453 | int execute_in_process_context(work_func_t fn, struct execute_work *); |
1da177e4 | 454 | |
401a8d04 | 455 | extern bool flush_work(struct work_struct *work); |
73b4b532 | 456 | extern bool cancel_work(struct work_struct *work); |
401a8d04 TH |
457 | extern bool cancel_work_sync(struct work_struct *work); |
458 | ||
459 | extern bool flush_delayed_work(struct delayed_work *dwork); | |
57b30ae7 | 460 | extern bool cancel_delayed_work(struct delayed_work *dwork); |
401a8d04 | 461 | extern bool cancel_delayed_work_sync(struct delayed_work *dwork); |
28e53bdd | 462 | |
05f0fe6b TH |
463 | extern bool flush_rcu_work(struct rcu_work *rwork); |
464 | ||
dcd989cb TH |
465 | extern void workqueue_set_max_active(struct workqueue_struct *wq, |
466 | int max_active); | |
27d4ee03 | 467 | extern struct work_struct *current_work(void); |
e6267616 | 468 | extern bool current_is_workqueue_rescuer(void); |
d84ff051 | 469 | extern bool workqueue_congested(int cpu, struct workqueue_struct *wq); |
dcd989cb | 470 | extern unsigned int work_busy(struct work_struct *work); |
3d1cb205 TH |
471 | extern __printf(1, 2) void set_worker_desc(const char *fmt, ...); |
472 | extern void print_worker_info(const char *log_lvl, struct task_struct *task); | |
55df0933 IK |
473 | extern void show_all_workqueues(void); |
474 | extern void show_one_workqueue(struct workqueue_struct *wq); | |
6b59808b | 475 | extern void wq_worker_comm(char *buf, size_t size, struct task_struct *task); |
dcd989cb | 476 | |
8425e3d5 TH |
477 | /** |
478 | * queue_work - queue work on a workqueue | |
479 | * @wq: workqueue to use | |
480 | * @work: work to queue | |
481 | * | |
482 | * Returns %false if @work was already on a queue, %true otherwise. | |
483 | * | |
484 | * We queue the work to the CPU on which it was submitted, but if the CPU dies | |
485 | * it can be processed by another CPU. | |
dbb92f88 AP |
486 | * |
487 | * Memory-ordering properties: If it returns %true, guarantees that all stores | |
488 | * preceding the call to queue_work() in the program order will be visible from | |
489 | * the CPU which will execute @work by the time such work executes, e.g., | |
490 | * | |
491 | * { x is initially 0 } | |
492 | * | |
493 | * CPU0 CPU1 | |
494 | * | |
495 | * WRITE_ONCE(x, 1); [ @work is being executed ] | |
496 | * r0 = queue_work(wq, work); r1 = READ_ONCE(x); | |
497 | * | |
498 | * Forbids: r0 == true && r1 == 0 | |
8425e3d5 TH |
499 | */ |
500 | static inline bool queue_work(struct workqueue_struct *wq, | |
501 | struct work_struct *work) | |
502 | { | |
503 | return queue_work_on(WORK_CPU_UNBOUND, wq, work); | |
504 | } | |
505 | ||
506 | /** | |
507 | * queue_delayed_work - queue work on a workqueue after delay | |
508 | * @wq: workqueue to use | |
509 | * @dwork: delayable work to queue | |
510 | * @delay: number of jiffies to wait before queueing | |
511 | * | |
512 | * Equivalent to queue_delayed_work_on() but tries to use the local CPU. | |
513 | */ | |
514 | static inline bool queue_delayed_work(struct workqueue_struct *wq, | |
515 | struct delayed_work *dwork, | |
516 | unsigned long delay) | |
517 | { | |
518 | return queue_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay); | |
519 | } | |
520 | ||
521 | /** | |
522 | * mod_delayed_work - modify delay of or queue a delayed work | |
523 | * @wq: workqueue to use | |
524 | * @dwork: work to queue | |
525 | * @delay: number of jiffies to wait before queueing | |
526 | * | |
527 | * mod_delayed_work_on() on local CPU. | |
528 | */ | |
529 | static inline bool mod_delayed_work(struct workqueue_struct *wq, | |
530 | struct delayed_work *dwork, | |
531 | unsigned long delay) | |
532 | { | |
533 | return mod_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay); | |
534 | } | |
535 | ||
536 | /** | |
537 | * schedule_work_on - put work task on a specific cpu | |
538 | * @cpu: cpu to put the work task on | |
539 | * @work: job to be done | |
540 | * | |
541 | * This puts a job on a specific cpu | |
542 | */ | |
543 | static inline bool schedule_work_on(int cpu, struct work_struct *work) | |
544 | { | |
545 | return queue_work_on(cpu, system_wq, work); | |
546 | } | |
547 | ||
548 | /** | |
549 | * schedule_work - put work task in global workqueue | |
550 | * @work: job to be done | |
551 | * | |
552 | * Returns %false if @work was already on the kernel-global workqueue and | |
553 | * %true otherwise. | |
554 | * | |
555 | * This puts a job in the kernel-global workqueue if it was not already | |
556 | * queued and leaves it in the same position on the kernel-global | |
557 | * workqueue otherwise. | |
dbb92f88 AP |
558 | * |
559 | * Shares the same memory-ordering properties of queue_work(), cf. the | |
560 | * DocBook header of queue_work(). | |
8425e3d5 TH |
561 | */ |
562 | static inline bool schedule_work(struct work_struct *work) | |
563 | { | |
564 | return queue_work(system_wq, work); | |
565 | } | |
566 | ||
c4f135d6 TH |
567 | /* |
568 | * Detect attempt to flush system-wide workqueues at compile time when possible. | |
569 | * | |
570 | * See https://lkml.kernel.org/r/49925af7-78a8-a3dd-bce6-cfc02e1a9236@I-love.SAKURA.ne.jp | |
571 | * for reasons and steps for converting system-wide workqueues into local workqueues. | |
572 | */ | |
573 | extern void __warn_flushing_systemwide_wq(void) | |
574 | __compiletime_warning("Please avoid flushing system-wide workqueues."); | |
575 | ||
37b1ef31 LJ |
576 | /** |
577 | * flush_scheduled_work - ensure that any scheduled work has run to completion. | |
578 | * | |
579 | * Forces execution of the kernel-global workqueue and blocks until its | |
580 | * completion. | |
581 | * | |
c4f135d6 TH |
582 | * It's very easy to get into trouble if you don't take great care. |
583 | * Either of the following situations will lead to deadlock: | |
37b1ef31 LJ |
584 | * |
585 | * One of the work items currently on the workqueue needs to acquire | |
586 | * a lock held by your code or its caller. | |
587 | * | |
588 | * Your code is running in the context of a work routine. | |
589 | * | |
590 | * They will be detected by lockdep when they occur, but the first might not | |
591 | * occur very often. It depends on what work items are on the workqueue and | |
592 | * what locks they need, which you have no control over. | |
593 | * | |
594 | * In most situations flushing the entire workqueue is overkill; you merely | |
595 | * need to know that a particular work item isn't queued and isn't running. | |
596 | * In such cases you should use cancel_delayed_work_sync() or | |
597 | * cancel_work_sync() instead. | |
c4f135d6 TH |
598 | * |
599 | * Please stop calling this function! A conversion to stop flushing system-wide | |
600 | * workqueues is in progress. This function will be removed after all in-tree | |
601 | * users stopped calling this function. | |
37b1ef31 | 602 | */ |
c4f135d6 TH |
603 | /* |
604 | * The background of commit 771c035372a036f8 ("deprecate the | |
605 | * '__deprecated' attribute warnings entirely and for good") is that, | |
606 | * since Linus builds all modules between every single pull he does, | |
607 | * the standard kernel build needs to be _clean_ in order to be able to | |
608 | * notice when new problems happen. Therefore, don't emit warning while | |
609 | * there are in-tree users. | |
610 | */ | |
611 | #define flush_scheduled_work() \ | |
612 | ({ \ | |
613 | if (0) \ | |
614 | __warn_flushing_systemwide_wq(); \ | |
615 | __flush_workqueue(system_wq); \ | |
616 | }) | |
617 | ||
618 | /* | |
619 | * Although there is no longer in-tree caller, for now just emit warning | |
620 | * in order to give out-of-tree callers time to update. | |
621 | */ | |
622 | #define flush_workqueue(wq) \ | |
623 | ({ \ | |
624 | struct workqueue_struct *_wq = (wq); \ | |
625 | \ | |
626 | if ((__builtin_constant_p(_wq == system_wq) && \ | |
627 | _wq == system_wq) || \ | |
628 | (__builtin_constant_p(_wq == system_highpri_wq) && \ | |
629 | _wq == system_highpri_wq) || \ | |
630 | (__builtin_constant_p(_wq == system_long_wq) && \ | |
631 | _wq == system_long_wq) || \ | |
632 | (__builtin_constant_p(_wq == system_unbound_wq) && \ | |
633 | _wq == system_unbound_wq) || \ | |
634 | (__builtin_constant_p(_wq == system_freezable_wq) && \ | |
635 | _wq == system_freezable_wq) || \ | |
636 | (__builtin_constant_p(_wq == system_power_efficient_wq) && \ | |
637 | _wq == system_power_efficient_wq) || \ | |
638 | (__builtin_constant_p(_wq == system_freezable_power_efficient_wq) && \ | |
639 | _wq == system_freezable_power_efficient_wq)) \ | |
640 | __warn_flushing_systemwide_wq(); \ | |
641 | __flush_workqueue(_wq); \ | |
642 | }) | |
37b1ef31 | 643 | |
8425e3d5 TH |
644 | /** |
645 | * schedule_delayed_work_on - queue work in global workqueue on CPU after delay | |
646 | * @cpu: cpu to use | |
647 | * @dwork: job to be done | |
648 | * @delay: number of jiffies to wait | |
649 | * | |
650 | * After waiting for a given time this puts a job in the kernel-global | |
651 | * workqueue on the specified CPU. | |
652 | */ | |
653 | static inline bool schedule_delayed_work_on(int cpu, struct delayed_work *dwork, | |
654 | unsigned long delay) | |
655 | { | |
656 | return queue_delayed_work_on(cpu, system_wq, dwork, delay); | |
657 | } | |
658 | ||
659 | /** | |
660 | * schedule_delayed_work - put work task in global workqueue after delay | |
661 | * @dwork: job to be done | |
662 | * @delay: number of jiffies to wait or 0 for immediate execution | |
663 | * | |
664 | * After waiting for a given time this puts a job in the kernel-global | |
665 | * workqueue. | |
666 | */ | |
667 | static inline bool schedule_delayed_work(struct delayed_work *dwork, | |
668 | unsigned long delay) | |
669 | { | |
670 | return queue_delayed_work(system_wq, dwork, delay); | |
671 | } | |
672 | ||
2d3854a3 | 673 | #ifndef CONFIG_SMP |
d84ff051 | 674 | static inline long work_on_cpu(int cpu, long (*fn)(void *), void *arg) |
2d3854a3 RR |
675 | { |
676 | return fn(arg); | |
677 | } | |
0e8d6a93 TG |
678 | static inline long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg) |
679 | { | |
680 | return fn(arg); | |
681 | } | |
2d3854a3 | 682 | #else |
d84ff051 | 683 | long work_on_cpu(int cpu, long (*fn)(void *), void *arg); |
0e8d6a93 | 684 | long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg); |
2d3854a3 | 685 | #endif /* CONFIG_SMP */ |
a25909a4 | 686 | |
a0a1a5fd TH |
687 | #ifdef CONFIG_FREEZER |
688 | extern void freeze_workqueues_begin(void); | |
689 | extern bool freeze_workqueues_busy(void); | |
690 | extern void thaw_workqueues(void); | |
691 | #endif /* CONFIG_FREEZER */ | |
692 | ||
226223ab TH |
693 | #ifdef CONFIG_SYSFS |
694 | int workqueue_sysfs_register(struct workqueue_struct *wq); | |
695 | #else /* CONFIG_SYSFS */ | |
696 | static inline int workqueue_sysfs_register(struct workqueue_struct *wq) | |
697 | { return 0; } | |
698 | #endif /* CONFIG_SYSFS */ | |
699 | ||
82607adc TH |
700 | #ifdef CONFIG_WQ_WATCHDOG |
701 | void wq_watchdog_touch(int cpu); | |
702 | #else /* CONFIG_WQ_WATCHDOG */ | |
703 | static inline void wq_watchdog_touch(int cpu) { } | |
704 | #endif /* CONFIG_WQ_WATCHDOG */ | |
705 | ||
7ee681b2 TG |
706 | #ifdef CONFIG_SMP |
707 | int workqueue_prepare_cpu(unsigned int cpu); | |
708 | int workqueue_online_cpu(unsigned int cpu); | |
709 | int workqueue_offline_cpu(unsigned int cpu); | |
710 | #endif | |
711 | ||
2333e829 YC |
712 | void __init workqueue_init_early(void); |
713 | void __init workqueue_init(void); | |
3347fa09 | 714 | |
1da177e4 | 715 | #endif |