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Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001/* SPDX-License-Identifier: GPL-2.0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002/*
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>
Johannes Berg4e6045f2007-10-18 23:39:55 -070012#include <linux/lockdep.h>
Tejun Heo7a22ad72010-06-29 10:07:13 +020013#include <linux/threads.h>
Arun Sharma600634972011-07-26 16:09:06 -070014#include <linux/atomic.h>
Tejun Heo7a4e3442013-03-12 11:30:00 -070015#include <linux/cpumask.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016
17struct workqueue_struct;
18
David Howells65f27f32006-11-22 14:55:48 +000019struct work_struct;
20typedef void (*work_func_t)(struct work_struct *work);
Kees Cook8c20feb2017-10-04 16:27:07 -070021void delayed_work_timer_fn(struct timer_list *t);
David Howells6bb49e52006-11-22 14:54:45 +000022
Linus Torvaldsa08727b2006-12-16 09:53:50 -080023/*
24 * The first word is the work queue pointer and the flags rolled into
25 * one
26 */
27#define work_data_bits(work) ((unsigned long *)(&(work)->data))
28
Tejun Heo22df02b2010-06-29 10:07:10 +020029enum {
30 WORK_STRUCT_PENDING_BIT = 0, /* work item is pending execution */
Tejun Heo8a2e8e5d2010-08-25 10:33:56 +020031 WORK_STRUCT_DELAYED_BIT = 1, /* work item is delayed */
Tejun Heo112202d2013-02-13 19:29:12 -080032 WORK_STRUCT_PWQ_BIT = 2, /* data points to pwq */
Tejun Heo8a2e8e5d2010-08-25 10:33:56 +020033 WORK_STRUCT_LINKED_BIT = 3, /* next work is linked to this one */
Tejun Heo22df02b2010-06-29 10:07:10 +020034#ifdef CONFIG_DEBUG_OBJECTS_WORK
Tejun Heo8a2e8e5d2010-08-25 10:33:56 +020035 WORK_STRUCT_STATIC_BIT = 4, /* static initializer (debugobjects) */
36 WORK_STRUCT_COLOR_SHIFT = 5, /* color for workqueue flushing */
Tejun Heo0f900042010-06-29 10:07:11 +020037#else
Tejun Heo8a2e8e5d2010-08-25 10:33:56 +020038 WORK_STRUCT_COLOR_SHIFT = 4, /* color for workqueue flushing */
Tejun Heo22df02b2010-06-29 10:07:10 +020039#endif
40
Tejun Heo73f53c42010-06-29 10:07:11 +020041 WORK_STRUCT_COLOR_BITS = 4,
42
Tejun Heo22df02b2010-06-29 10:07:10 +020043 WORK_STRUCT_PENDING = 1 << WORK_STRUCT_PENDING_BIT,
Tejun Heo8a2e8e5d2010-08-25 10:33:56 +020044 WORK_STRUCT_DELAYED = 1 << WORK_STRUCT_DELAYED_BIT,
Tejun Heo112202d2013-02-13 19:29:12 -080045 WORK_STRUCT_PWQ = 1 << WORK_STRUCT_PWQ_BIT,
Tejun Heoaffee4b2010-06-29 10:07:12 +020046 WORK_STRUCT_LINKED = 1 << WORK_STRUCT_LINKED_BIT,
Tejun Heo22df02b2010-06-29 10:07:10 +020047#ifdef CONFIG_DEBUG_OBJECTS_WORK
48 WORK_STRUCT_STATIC = 1 << WORK_STRUCT_STATIC_BIT,
49#else
50 WORK_STRUCT_STATIC = 0,
51#endif
52
Tejun Heo73f53c42010-06-29 10:07:11 +020053 /*
54 * The last color is no color used for works which don't
55 * participate in workqueue flushing.
56 */
57 WORK_NR_COLORS = (1 << WORK_STRUCT_COLOR_BITS) - 1,
58 WORK_NO_COLOR = WORK_NR_COLORS,
59
Lai Jiangshan79bc251f2014-05-22 16:43:44 +080060 /* not bound to any CPU, prefer the local CPU */
Tejun Heof3421792010-07-02 10:03:51 +020061 WORK_CPU_UNBOUND = NR_CPUS,
Tejun Heobdbc5dd2010-07-02 10:03:51 +020062
Tejun Heo73f53c42010-06-29 10:07:11 +020063 /*
Tejun Heo112202d2013-02-13 19:29:12 -080064 * Reserve 7 bits off of pwq pointer w/ debugobjects turned off.
65 * This makes pwqs aligned to 256 bytes and allows 15 workqueue
66 * flush colors.
Tejun Heo73f53c42010-06-29 10:07:11 +020067 */
68 WORK_STRUCT_FLAG_BITS = WORK_STRUCT_COLOR_SHIFT +
69 WORK_STRUCT_COLOR_BITS,
70
Tejun Heo112202d2013-02-13 19:29:12 -080071 /* data contains off-queue information when !WORK_STRUCT_PWQ */
Lai Jiangshan45d95502013-02-19 12:17:01 -080072 WORK_OFFQ_FLAG_BASE = WORK_STRUCT_COLOR_SHIFT,
Tejun Heobbb68df2012-08-03 10:30:46 -070073
Tejun Heo8603e1b32015-03-05 08:04:13 -050074 __WORK_OFFQ_CANCELING = WORK_OFFQ_FLAG_BASE,
75 WORK_OFFQ_CANCELING = (1 << __WORK_OFFQ_CANCELING),
Tejun Heobbb68df2012-08-03 10:30:46 -070076
Tejun Heo715b06b2013-01-24 11:01:33 -080077 /*
78 * When a work item is off queue, its high bits point to the last
Tejun Heo7c3eed52013-01-24 11:01:33 -080079 * pool it was on. Cap at 31 bits and use the highest number to
80 * indicate that no pool is associated.
Tejun Heo715b06b2013-01-24 11:01:33 -080081 */
Tejun Heobbb68df2012-08-03 10:30:46 -070082 WORK_OFFQ_FLAG_BITS = 1,
Tejun Heo7c3eed52013-01-24 11:01:33 -080083 WORK_OFFQ_POOL_SHIFT = WORK_OFFQ_FLAG_BASE + WORK_OFFQ_FLAG_BITS,
84 WORK_OFFQ_LEFT = BITS_PER_LONG - WORK_OFFQ_POOL_SHIFT,
85 WORK_OFFQ_POOL_BITS = WORK_OFFQ_LEFT <= 31 ? WORK_OFFQ_LEFT : 31,
86 WORK_OFFQ_POOL_NONE = (1LU << WORK_OFFQ_POOL_BITS) - 1,
Tejun Heob5490072012-08-03 10:30:46 -070087
88 /* convenience constants */
Tejun Heo0f900042010-06-29 10:07:11 +020089 WORK_STRUCT_FLAG_MASK = (1UL << WORK_STRUCT_FLAG_BITS) - 1,
Tejun Heo22df02b2010-06-29 10:07:10 +020090 WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK,
Tejun Heo7c3eed52013-01-24 11:01:33 -080091 WORK_STRUCT_NO_POOL = (unsigned long)WORK_OFFQ_POOL_NONE << WORK_OFFQ_POOL_SHIFT,
Tejun Heodcd989c2010-06-29 10:07:14 +020092
93 /* bit mask for work_busy() return values */
94 WORK_BUSY_PENDING = 1 << 0,
95 WORK_BUSY_RUNNING = 1 << 1,
Tejun Heo3d1cb202013-04-30 15:27:22 -070096
97 /* maximum string length for set_worker_desc() */
98 WORKER_DESC_LEN = 24,
Tejun Heo22df02b2010-06-29 10:07:10 +020099};
100
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101struct work_struct {
Linus Torvaldsa08727b2006-12-16 09:53:50 -0800102 atomic_long_t data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 struct list_head entry;
David Howells6bb49e52006-11-22 14:54:45 +0000104 work_func_t func;
Johannes Berg4e6045f2007-10-18 23:39:55 -0700105#ifdef CONFIG_LOCKDEP
106 struct lockdep_map lockdep_map;
107#endif
David Howells52bad642006-11-22 14:54:01 +0000108};
109
Arnd Bergmanna45463c2017-02-01 18:01:17 +0100110#define WORK_DATA_INIT() ATOMIC_LONG_INIT((unsigned long)WORK_STRUCT_NO_POOL)
Tejun Heo7a22ad72010-06-29 10:07:13 +0200111#define WORK_DATA_STATIC_INIT() \
Arnd Bergmanna45463c2017-02-01 18:01:17 +0100112 ATOMIC_LONG_INIT((unsigned long)(WORK_STRUCT_NO_POOL | WORK_STRUCT_STATIC))
Linus Torvaldsa08727b2006-12-16 09:53:50 -0800113
David Howells52bad642006-11-22 14:54:01 +0000114struct delayed_work {
115 struct work_struct work;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 struct timer_list timer;
Lai Jiangshan60c057b2013-02-06 18:04:53 -0800117
118 /* target workqueue and CPU ->timer uses to queue ->work */
119 struct workqueue_struct *wq;
Tejun Heo12650572012-08-08 09:38:42 -0700120 int cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121};
122
Silvio Fricke42412c32016-10-28 10:14:09 +0200123/**
124 * struct workqueue_attrs - A struct for workqueue attributes.
Tejun Heod55262c2013-04-01 11:23:38 -0700125 *
Silvio Fricke42412c32016-10-28 10:14:09 +0200126 * This can be used to change attributes of an unbound workqueue.
Tejun Heo7a4e3442013-03-12 11:30:00 -0700127 */
128struct workqueue_attrs {
Silvio Fricke42412c32016-10-28 10:14:09 +0200129 /**
130 * @nice: nice level
131 */
132 int nice;
133
134 /**
135 * @cpumask: allowed CPUs
136 */
137 cpumask_var_t cpumask;
138
139 /**
140 * @no_numa: disable NUMA affinity
141 *
142 * Unlike other fields, ``no_numa`` isn't a property of a worker_pool. It
143 * only modifies how :c:func:`apply_workqueue_attrs` select pools and thus
144 * doesn't participate in pool hash calculations or equality comparisons.
145 */
146 bool no_numa;
Tejun Heo7a4e3442013-03-12 11:30:00 -0700147};
148
Jean Delvarebf6aede2009-04-02 16:56:54 -0700149static inline struct delayed_work *to_delayed_work(struct work_struct *work)
150{
151 return container_of(work, struct delayed_work, work);
152}
153
James Bottomley1fa44ec2006-02-23 12:43:43 -0600154struct execute_work {
155 struct work_struct work;
156};
157
Johannes Berg4e6045f2007-10-18 23:39:55 -0700158#ifdef CONFIG_LOCKDEP
159/*
160 * NB: because we have to copy the lockdep_map, setting _key
161 * here is required, otherwise it could get initialised to the
162 * copy of the lockdep_map!
163 */
164#define __WORK_INIT_LOCKDEP_MAP(n, k) \
165 .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
166#else
167#define __WORK_INIT_LOCKDEP_MAP(n, k)
168#endif
169
Tejun Heoee64e7f2012-08-21 13:18:23 -0700170#define __WORK_INITIALIZER(n, f) { \
171 .data = WORK_DATA_STATIC_INIT(), \
172 .entry = { &(n).entry, &(n).entry }, \
173 .func = (f), \
174 __WORK_INIT_LOCKDEP_MAP(#n, &(n)) \
David Howells65f27f32006-11-22 14:55:48 +0000175 }
176
Tejun Heof991b312012-08-21 13:18:23 -0700177#define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \
Tejun Heoee64e7f2012-08-21 13:18:23 -0700178 .work = __WORK_INITIALIZER((n).work, (f)), \
Kees Cook841b86f2017-10-23 09:40:42 +0200179 .timer = __TIMER_INITIALIZER(delayed_work_timer_fn,\
Tejun Heoe0aecdd2012-08-21 13:18:24 -0700180 (tflags) | TIMER_IRQSAFE), \
Phil Carmodydd6414b2010-10-20 15:57:33 -0700181 }
182
Tejun Heoee64e7f2012-08-21 13:18:23 -0700183#define DECLARE_WORK(n, f) \
David Howells65f27f32006-11-22 14:55:48 +0000184 struct work_struct n = __WORK_INITIALIZER(n, f)
185
Tejun Heoee64e7f2012-08-21 13:18:23 -0700186#define DECLARE_DELAYED_WORK(n, f) \
Tejun Heof991b312012-08-21 13:18:23 -0700187 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0)
David Howells65f27f32006-11-22 14:55:48 +0000188
Tejun Heo203b42f2012-08-21 13:18:23 -0700189#define DECLARE_DEFERRABLE_WORK(n, f) \
Tejun Heof991b312012-08-21 13:18:23 -0700190 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, TIMER_DEFERRABLE)
Phil Carmodydd6414b2010-10-20 15:57:33 -0700191
Thomas Gleixnerdc186ad2009-11-16 01:09:48 +0900192#ifdef CONFIG_DEBUG_OBJECTS_WORK
193extern void __init_work(struct work_struct *work, int onstack);
194extern void destroy_work_on_stack(struct work_struct *work);
Thomas Gleixnerea2e64f2014-03-23 14:20:44 +0000195extern void destroy_delayed_work_on_stack(struct delayed_work *work);
Tejun Heo4690c4a2010-06-29 10:07:10 +0200196static inline unsigned int work_static(struct work_struct *work)
197{
Tejun Heo22df02b2010-06-29 10:07:10 +0200198 return *work_data_bits(work) & WORK_STRUCT_STATIC;
Tejun Heo4690c4a2010-06-29 10:07:10 +0200199}
Thomas Gleixnerdc186ad2009-11-16 01:09:48 +0900200#else
201static inline void __init_work(struct work_struct *work, int onstack) { }
202static inline void destroy_work_on_stack(struct work_struct *work) { }
Thomas Gleixnerea2e64f2014-03-23 14:20:44 +0000203static inline void destroy_delayed_work_on_stack(struct delayed_work *work) { }
Tejun Heo4690c4a2010-06-29 10:07:10 +0200204static inline unsigned int work_static(struct work_struct *work) { return 0; }
Thomas Gleixnerdc186ad2009-11-16 01:09:48 +0900205#endif
206
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207/*
David Howells52bad642006-11-22 14:54:01 +0000208 * initialize all of a work item in one go
Linus Torvaldsa08727b2006-12-16 09:53:50 -0800209 *
Dmitri Vorobievb9049df2009-06-23 12:09:29 +0200210 * NOTE! No point in using "atomic_long_set()": using a direct
Linus Torvaldsa08727b2006-12-16 09:53:50 -0800211 * assignment of the work data initializer allows the compiler
212 * to generate better code.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 */
Johannes Berg4e6045f2007-10-18 23:39:55 -0700214#ifdef CONFIG_LOCKDEP
Thomas Gleixnerdc186ad2009-11-16 01:09:48 +0900215#define __INIT_WORK(_work, _func, _onstack) \
Johannes Berg4e6045f2007-10-18 23:39:55 -0700216 do { \
217 static struct lock_class_key __key; \
218 \
Thomas Gleixnerdc186ad2009-11-16 01:09:48 +0900219 __init_work((_work), _onstack); \
Johannes Berg4e6045f2007-10-18 23:39:55 -0700220 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
Byungchul Parkfd1a5b02017-10-25 17:56:04 +0900221 lockdep_init_map(&(_work)->lockdep_map, "(work_completion)"#_work, &__key, 0); \
Johannes Berg4e6045f2007-10-18 23:39:55 -0700222 INIT_LIST_HEAD(&(_work)->entry); \
Tejun Heof073f922014-03-07 10:24:50 -0500223 (_work)->func = (_func); \
Johannes Berg4e6045f2007-10-18 23:39:55 -0700224 } while (0)
225#else
Thomas Gleixnerdc186ad2009-11-16 01:09:48 +0900226#define __INIT_WORK(_work, _func, _onstack) \
David Howells65f27f32006-11-22 14:55:48 +0000227 do { \
Thomas Gleixnerdc186ad2009-11-16 01:09:48 +0900228 __init_work((_work), _onstack); \
Oleg Nesterov23b2e592007-05-09 02:34:19 -0700229 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
David Howells65f27f32006-11-22 14:55:48 +0000230 INIT_LIST_HEAD(&(_work)->entry); \
Tejun Heof073f922014-03-07 10:24:50 -0500231 (_work)->func = (_func); \
David Howells65f27f32006-11-22 14:55:48 +0000232 } while (0)
Johannes Berg4e6045f2007-10-18 23:39:55 -0700233#endif
David Howells65f27f32006-11-22 14:55:48 +0000234
Tejun Heoee64e7f2012-08-21 13:18:23 -0700235#define INIT_WORK(_work, _func) \
Valentin Rothberg9da7dae2015-01-06 17:29:29 +0100236 __INIT_WORK((_work), (_func), 0)
Thomas Gleixnerdc186ad2009-11-16 01:09:48 +0900237
Tejun Heoee64e7f2012-08-21 13:18:23 -0700238#define INIT_WORK_ONSTACK(_work, _func) \
Valentin Rothberg9da7dae2015-01-06 17:29:29 +0100239 __INIT_WORK((_work), (_func), 1)
Thomas Gleixnerdc186ad2009-11-16 01:09:48 +0900240
Tejun Heof991b312012-08-21 13:18:23 -0700241#define __INIT_DELAYED_WORK(_work, _func, _tflags) \
Tejun Heoee64e7f2012-08-21 13:18:23 -0700242 do { \
243 INIT_WORK(&(_work)->work, (_func)); \
Kees Cook919b2502017-10-22 18:48:43 -0700244 __init_timer(&(_work)->timer, \
245 delayed_work_timer_fn, \
246 (_tflags) | TIMER_IRQSAFE); \
David Howells65f27f32006-11-22 14:55:48 +0000247 } while (0)
248
Tejun Heof991b312012-08-21 13:18:23 -0700249#define __INIT_DELAYED_WORK_ONSTACK(_work, _func, _tflags) \
Tejun Heoee64e7f2012-08-21 13:18:23 -0700250 do { \
251 INIT_WORK_ONSTACK(&(_work)->work, (_func)); \
Kees Cook919b2502017-10-22 18:48:43 -0700252 __init_timer_on_stack(&(_work)->timer, \
253 delayed_work_timer_fn, \
254 (_tflags) | TIMER_IRQSAFE); \
Peter Zijlstra6d612b02009-01-12 12:52:23 +0100255 } while (0)
256
Tejun Heof991b312012-08-21 13:18:23 -0700257#define INIT_DELAYED_WORK(_work, _func) \
258 __INIT_DELAYED_WORK(_work, _func, 0)
259
260#define INIT_DELAYED_WORK_ONSTACK(_work, _func) \
261 __INIT_DELAYED_WORK_ONSTACK(_work, _func, 0)
262
Tejun Heo203b42f2012-08-21 13:18:23 -0700263#define INIT_DEFERRABLE_WORK(_work, _func) \
Tejun Heof991b312012-08-21 13:18:23 -0700264 __INIT_DELAYED_WORK(_work, _func, TIMER_DEFERRABLE)
265
266#define INIT_DEFERRABLE_WORK_ONSTACK(_work, _func) \
267 __INIT_DELAYED_WORK_ONSTACK(_work, _func, TIMER_DEFERRABLE)
Venki Pallipadi28287032007-05-08 00:27:47 -0700268
David Howells365970a2006-11-22 14:54:49 +0000269/**
270 * work_pending - Find out whether a work item is currently pending
271 * @work: The work item in question
272 */
273#define work_pending(work) \
Tejun Heo22df02b2010-06-29 10:07:10 +0200274 test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
David Howells365970a2006-11-22 14:54:49 +0000275
276/**
277 * delayed_work_pending - Find out whether a delayable work item is currently
278 * pending
Jonathan Corbet355c06632015-08-13 17:52:02 -0600279 * @w: The work item in question
David Howells365970a2006-11-22 14:54:49 +0000280 */
Linus Torvalds02218722006-12-15 14:13:51 -0800281#define delayed_work_pending(w) \
282 work_pending(&(w)->work)
David Howells365970a2006-11-22 14:54:49 +0000283
Tejun Heoc54fce62010-09-10 16:51:36 +0200284/*
285 * Workqueue flags and constants. For details, please refer to
Silvio Fricke42412c32016-10-28 10:14:09 +0200286 * Documentation/core-api/workqueue.rst.
Tejun Heoc54fce62010-09-10 16:51:36 +0200287 */
Tejun Heo97e37d72010-06-29 10:07:10 +0200288enum {
Tejun Heoc7fc77f2010-07-02 10:03:51 +0200289 WQ_UNBOUND = 1 << 1, /* not bound to any cpu */
Tejun Heo58a69cb2011-02-16 09:25:31 +0100290 WQ_FREEZABLE = 1 << 2, /* freeze during suspend */
Tejun Heo6370a6a2010-10-11 15:12:27 +0200291 WQ_MEM_RECLAIM = 1 << 3, /* may be used for memory reclaim */
Tejun Heo649027d2010-06-29 10:07:14 +0200292 WQ_HIGHPRI = 1 << 4, /* high priority */
Geert Uytterhoeven41f50092014-03-24 21:37:02 +0100293 WQ_CPU_INTENSIVE = 1 << 5, /* cpu intensive workqueue */
Tejun Heo226223a2013-03-12 11:30:05 -0700294 WQ_SYSFS = 1 << 6, /* visible in sysfs, see wq_sysfs_register() */
Tejun Heob71ab8c2010-06-29 10:07:14 +0200295
Viresh Kumarcee22a12013-04-08 16:45:40 +0530296 /*
297 * Per-cpu workqueues are generally preferred because they tend to
298 * show better performance thanks to cache locality. Per-cpu
299 * workqueues exclude the scheduler from choosing the CPU to
300 * execute the worker threads, which has an unfortunate side effect
301 * of increasing power consumption.
302 *
303 * The scheduler considers a CPU idle if it doesn't have any task
304 * to execute and tries to keep idle cores idle to conserve power;
305 * however, for example, a per-cpu work item scheduled from an
306 * interrupt handler on an idle CPU will force the scheduler to
307 * excute the work item on that CPU breaking the idleness, which in
308 * turn may lead to more scheduling choices which are sub-optimal
309 * in terms of power consumption.
310 *
311 * Workqueues marked with WQ_POWER_EFFICIENT are per-cpu by default
312 * but become unbound if workqueue.power_efficient kernel param is
313 * specified. Per-cpu workqueues which are identified to
314 * contribute significantly to power-consumption are identified and
315 * marked with this flag and enabling the power_efficient mode
316 * leads to noticeable power saving at the cost of small
317 * performance disadvantage.
318 *
319 * http://thread.gmane.org/gmane.linux.kernel/1480396
320 */
321 WQ_POWER_EFFICIENT = 1 << 7,
322
Tejun Heo618b01e2013-03-12 11:30:04 -0700323 __WQ_DRAINING = 1 << 16, /* internal: workqueue is draining */
Tejun Heo8719dce2013-03-12 11:30:04 -0700324 __WQ_ORDERED = 1 << 17, /* internal: workqueue is ordered */
Tejun Heo23d11a52016-01-29 05:59:46 -0500325 __WQ_LEGACY = 1 << 18, /* internal: create*_workqueue() */
Ben Hutchingsfbf1c412017-09-03 01:18:41 +0100326 __WQ_ORDERED_EXPLICIT = 1 << 19, /* internal: alloc_ordered_workqueue() */
Tejun Heoe41e7042010-08-24 14:22:47 +0200327
Tejun Heob71ab8c2010-06-29 10:07:14 +0200328 WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */
Tejun Heof3421792010-07-02 10:03:51 +0200329 WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */
Tejun Heob71ab8c2010-06-29 10:07:14 +0200330 WQ_DFL_ACTIVE = WQ_MAX_ACTIVE / 2,
Tejun Heo97e37d72010-06-29 10:07:10 +0200331};
David Howells52bad642006-11-22 14:54:01 +0000332
Tejun Heof3421792010-07-02 10:03:51 +0200333/* unbound wq's aren't per-cpu, scale max_active according to #cpus */
334#define WQ_UNBOUND_MAX_ACTIVE \
335 max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU)
336
Tejun Heod320c032010-06-29 10:07:14 +0200337/*
338 * System-wide workqueues which are always present.
339 *
340 * system_wq is the one used by schedule[_delayed]_work[_on]().
341 * Multi-CPU multi-threaded. There are users which expect relatively
342 * short queue flush time. Don't queue works which can run for too
343 * long.
344 *
Lai Jiangshan73e43542014-05-22 16:42:41 +0800345 * system_highpri_wq is similar to system_wq but for work items which
346 * require WQ_HIGHPRI.
347 *
Tejun Heod320c032010-06-29 10:07:14 +0200348 * system_long_wq is similar to system_wq but may host long running
349 * works. Queue flushing might take relatively long.
350 *
Tejun Heof3421792010-07-02 10:03:51 +0200351 * system_unbound_wq is unbound workqueue. Workers are not bound to
352 * any specific CPU, not concurrency managed, and all queued works are
353 * executed immediately as long as max_active limit is not reached and
354 * resources are available.
Tejun Heo4149efb2011-02-08 10:39:03 +0100355 *
Tejun Heo24d51ad2011-02-21 09:52:50 +0100356 * system_freezable_wq is equivalent to system_wq except that it's
357 * freezable.
Viresh Kumar06681062013-04-24 17:12:54 +0530358 *
359 * *_power_efficient_wq are inclined towards saving power and converted
360 * into WQ_UNBOUND variants if 'wq_power_efficient' is enabled; otherwise,
361 * they are same as their non-power-efficient counterparts - e.g.
362 * system_power_efficient_wq is identical to system_wq if
363 * 'wq_power_efficient' is disabled. See WQ_POWER_EFFICIENT for more info.
Tejun Heod320c032010-06-29 10:07:14 +0200364 */
365extern struct workqueue_struct *system_wq;
Lai Jiangshan73e43542014-05-22 16:42:41 +0800366extern struct workqueue_struct *system_highpri_wq;
Tejun Heod320c032010-06-29 10:07:14 +0200367extern struct workqueue_struct *system_long_wq;
Tejun Heof3421792010-07-02 10:03:51 +0200368extern struct workqueue_struct *system_unbound_wq;
Tejun Heo24d51ad2011-02-21 09:52:50 +0100369extern struct workqueue_struct *system_freezable_wq;
Viresh Kumar06681062013-04-24 17:12:54 +0530370extern struct workqueue_struct *system_power_efficient_wq;
371extern struct workqueue_struct *system_freezable_power_efficient_wq;
Tejun Heoae930e02012-08-20 14:51:23 -0700372
Johannes Berg4e6045f2007-10-18 23:39:55 -0700373extern struct workqueue_struct *
Tejun Heob196be82012-01-10 15:11:35 -0800374__alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active,
375 struct lock_class_key *key, const char *lock_name, ...) __printf(1, 6);
Johannes Berg4e6045f2007-10-18 23:39:55 -0700376
Tejun Heob196be82012-01-10 15:11:35 -0800377/**
378 * alloc_workqueue - allocate a workqueue
379 * @fmt: printf format for the name of the workqueue
380 * @flags: WQ_* flags
381 * @max_active: max in-flight work items, 0 for default
Jonathan Corbet355c06632015-08-13 17:52:02 -0600382 * @args...: args for @fmt
Tejun Heob196be82012-01-10 15:11:35 -0800383 *
384 * Allocate a workqueue with the specified parameters. For detailed
Silvio Fricke42412c32016-10-28 10:14:09 +0200385 * information on WQ_* flags, please refer to
386 * Documentation/core-api/workqueue.rst.
Tejun Heob196be82012-01-10 15:11:35 -0800387 *
388 * The __lock_name macro dance is to guarantee that single lock_class_key
389 * doesn't end up with different namesm, which isn't allowed by lockdep.
390 *
391 * RETURNS:
392 * Pointer to the allocated workqueue on success, %NULL on failure.
393 */
Johannes Berg4e6045f2007-10-18 23:39:55 -0700394#ifdef CONFIG_LOCKDEP
Tejun Heoee64e7f2012-08-21 13:18:23 -0700395#define alloc_workqueue(fmt, flags, max_active, args...) \
396({ \
397 static struct lock_class_key __key; \
398 const char *__lock_name; \
399 \
Byungchul Parkfd1a5b02017-10-25 17:56:04 +0900400 __lock_name = "(wq_completion)"#fmt#args; \
Tejun Heoee64e7f2012-08-21 13:18:23 -0700401 \
402 __alloc_workqueue_key((fmt), (flags), (max_active), \
403 &__key, __lock_name, ##args); \
Johannes Berg4e6045f2007-10-18 23:39:55 -0700404})
405#else
Tejun Heoee64e7f2012-08-21 13:18:23 -0700406#define alloc_workqueue(fmt, flags, max_active, args...) \
407 __alloc_workqueue_key((fmt), (flags), (max_active), \
Tejun Heob196be82012-01-10 15:11:35 -0800408 NULL, NULL, ##args)
Johannes Berg4e6045f2007-10-18 23:39:55 -0700409#endif
410
Tejun Heo81dcaf62010-09-16 10:17:35 +0200411/**
412 * alloc_ordered_workqueue - allocate an ordered workqueue
Tejun Heob196be82012-01-10 15:11:35 -0800413 * @fmt: printf format for the name of the workqueue
Tejun Heo58a69cb2011-02-16 09:25:31 +0100414 * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
Jonathan Corbet355c06632015-08-13 17:52:02 -0600415 * @args...: args for @fmt
Tejun Heo81dcaf62010-09-16 10:17:35 +0200416 *
417 * Allocate an ordered workqueue. An ordered workqueue executes at
418 * most one work item at any given time in the queued order. They are
419 * implemented as unbound workqueues with @max_active of one.
420 *
421 * RETURNS:
422 * Pointer to the allocated workqueue on success, %NULL on failure.
423 */
Tejun Heoee64e7f2012-08-21 13:18:23 -0700424#define alloc_ordered_workqueue(fmt, flags, args...) \
Tejun Heo0a94efb2017-07-23 08:36:15 -0400425 alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | \
426 __WQ_ORDERED_EXPLICIT | (flags), 1, ##args)
Tejun Heo81dcaf62010-09-16 10:17:35 +0200427
Tejun Heoee64e7f2012-08-21 13:18:23 -0700428#define create_workqueue(name) \
Tejun Heo23d11a52016-01-29 05:59:46 -0500429 alloc_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, 1, (name))
Tejun Heoee64e7f2012-08-21 13:18:23 -0700430#define create_freezable_workqueue(name) \
Tejun Heo23d11a52016-01-29 05:59:46 -0500431 alloc_workqueue("%s", __WQ_LEGACY | WQ_FREEZABLE | WQ_UNBOUND | \
432 WQ_MEM_RECLAIM, 1, (name))
Tejun Heoee64e7f2012-08-21 13:18:23 -0700433#define create_singlethread_workqueue(name) \
Tejun Heo23d11a52016-01-29 05:59:46 -0500434 alloc_ordered_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435
436extern void destroy_workqueue(struct workqueue_struct *wq);
437
Tejun Heo7a4e3442013-03-12 11:30:00 -0700438struct workqueue_attrs *alloc_workqueue_attrs(gfp_t gfp_mask);
439void free_workqueue_attrs(struct workqueue_attrs *attrs);
Tejun Heo9e8cd2f2013-03-12 11:30:04 -0700440int apply_workqueue_attrs(struct workqueue_struct *wq,
441 const struct workqueue_attrs *attrs);
Lai Jiangshan042f7df12015-04-30 17:16:12 +0800442int workqueue_set_unbound_cpumask(cpumask_var_t cpumask);
Tejun Heo7a4e3442013-03-12 11:30:00 -0700443
Tejun Heod4283e92012-08-03 10:30:44 -0700444extern bool queue_work_on(int cpu, struct workqueue_struct *wq,
Zhang Ruic1a220e2008-07-23 21:28:39 -0700445 struct work_struct *work);
Tejun Heod4283e92012-08-03 10:30:44 -0700446extern bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
Oleg Nesterov28e53bd2007-05-09 02:34:22 -0700447 struct delayed_work *work, unsigned long delay);
Tejun Heo8376fe22012-08-03 10:30:47 -0700448extern bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq,
449 struct delayed_work *dwork, unsigned long delay);
Oleg Nesterov28e53bd2007-05-09 02:34:22 -0700450
Harvey Harrisonb3c97522008-02-13 15:03:15 -0800451extern void flush_workqueue(struct workqueue_struct *wq);
Tejun Heo9c5a2ba2011-04-05 18:01:44 +0200452extern void drain_workqueue(struct workqueue_struct *wq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453
David Howells65f27f32006-11-22 14:55:48 +0000454extern int schedule_on_each_cpu(work_func_t func);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455
David Howells65f27f32006-11-22 14:55:48 +0000456int execute_in_process_context(work_func_t fn, struct execute_work *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457
Tejun Heo401a8d02010-09-16 10:36:00 +0200458extern bool flush_work(struct work_struct *work);
Jens Axboef72b8792016-08-24 15:51:50 -0600459extern bool cancel_work(struct work_struct *work);
Tejun Heo401a8d02010-09-16 10:36:00 +0200460extern bool cancel_work_sync(struct work_struct *work);
461
462extern bool flush_delayed_work(struct delayed_work *dwork);
Tejun Heo57b30ae2012-08-21 13:18:24 -0700463extern bool cancel_delayed_work(struct delayed_work *dwork);
Tejun Heo401a8d02010-09-16 10:36:00 +0200464extern bool cancel_delayed_work_sync(struct delayed_work *dwork);
Oleg Nesterov28e53bd2007-05-09 02:34:22 -0700465
Tejun Heodcd989c2010-06-29 10:07:14 +0200466extern void workqueue_set_max_active(struct workqueue_struct *wq,
467 int max_active);
Lukas Wunner27d4ee02018-02-11 10:38:28 +0100468extern struct work_struct *current_work(void);
Tejun Heoe62676162013-03-12 17:41:37 -0700469extern bool current_is_workqueue_rescuer(void);
Tejun Heod84ff052013-03-12 11:29:59 -0700470extern bool workqueue_congested(int cpu, struct workqueue_struct *wq);
Tejun Heodcd989c2010-06-29 10:07:14 +0200471extern unsigned int work_busy(struct work_struct *work);
Tejun Heo3d1cb202013-04-30 15:27:22 -0700472extern __printf(1, 2) void set_worker_desc(const char *fmt, ...);
473extern void print_worker_info(const char *log_lvl, struct task_struct *task);
Tejun Heo3494fc32015-03-09 09:22:28 -0400474extern void show_workqueue_state(void);
Tejun Heodcd989c2010-06-29 10:07:14 +0200475
Tejun Heo8425e3d52013-03-13 16:51:36 -0700476/**
477 * queue_work - queue work on a workqueue
478 * @wq: workqueue to use
479 * @work: work to queue
480 *
481 * Returns %false if @work was already on a queue, %true otherwise.
482 *
483 * We queue the work to the CPU on which it was submitted, but if the CPU dies
484 * it can be processed by another CPU.
485 */
486static inline bool queue_work(struct workqueue_struct *wq,
487 struct work_struct *work)
488{
489 return queue_work_on(WORK_CPU_UNBOUND, wq, work);
490}
491
492/**
493 * queue_delayed_work - queue work on a workqueue after delay
494 * @wq: workqueue to use
495 * @dwork: delayable work to queue
496 * @delay: number of jiffies to wait before queueing
497 *
498 * Equivalent to queue_delayed_work_on() but tries to use the local CPU.
499 */
500static inline bool queue_delayed_work(struct workqueue_struct *wq,
501 struct delayed_work *dwork,
502 unsigned long delay)
503{
504 return queue_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
505}
506
507/**
508 * mod_delayed_work - modify delay of or queue a delayed work
509 * @wq: workqueue to use
510 * @dwork: work to queue
511 * @delay: number of jiffies to wait before queueing
512 *
513 * mod_delayed_work_on() on local CPU.
514 */
515static inline bool mod_delayed_work(struct workqueue_struct *wq,
516 struct delayed_work *dwork,
517 unsigned long delay)
518{
519 return mod_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
520}
521
522/**
523 * schedule_work_on - put work task on a specific cpu
524 * @cpu: cpu to put the work task on
525 * @work: job to be done
526 *
527 * This puts a job on a specific cpu
528 */
529static inline bool schedule_work_on(int cpu, struct work_struct *work)
530{
531 return queue_work_on(cpu, system_wq, work);
532}
533
534/**
535 * schedule_work - put work task in global workqueue
536 * @work: job to be done
537 *
538 * Returns %false if @work was already on the kernel-global workqueue and
539 * %true otherwise.
540 *
541 * This puts a job in the kernel-global workqueue if it was not already
542 * queued and leaves it in the same position on the kernel-global
543 * workqueue otherwise.
544 */
545static inline bool schedule_work(struct work_struct *work)
546{
547 return queue_work(system_wq, work);
548}
549
550/**
Lai Jiangshan37b1ef32015-05-20 14:41:19 +0800551 * flush_scheduled_work - ensure that any scheduled work has run to completion.
552 *
553 * Forces execution of the kernel-global workqueue and blocks until its
554 * completion.
555 *
556 * Think twice before calling this function! It's very easy to get into
557 * trouble if you don't take great care. Either of the following situations
558 * will lead to deadlock:
559 *
560 * One of the work items currently on the workqueue needs to acquire
561 * a lock held by your code or its caller.
562 *
563 * Your code is running in the context of a work routine.
564 *
565 * They will be detected by lockdep when they occur, but the first might not
566 * occur very often. It depends on what work items are on the workqueue and
567 * what locks they need, which you have no control over.
568 *
569 * In most situations flushing the entire workqueue is overkill; you merely
570 * need to know that a particular work item isn't queued and isn't running.
571 * In such cases you should use cancel_delayed_work_sync() or
572 * cancel_work_sync() instead.
573 */
574static inline void flush_scheduled_work(void)
575{
576 flush_workqueue(system_wq);
577}
578
579/**
Tejun Heo8425e3d52013-03-13 16:51:36 -0700580 * schedule_delayed_work_on - queue work in global workqueue on CPU after delay
581 * @cpu: cpu to use
582 * @dwork: job to be done
583 * @delay: number of jiffies to wait
584 *
585 * After waiting for a given time this puts a job in the kernel-global
586 * workqueue on the specified CPU.
587 */
588static inline bool schedule_delayed_work_on(int cpu, struct delayed_work *dwork,
589 unsigned long delay)
590{
591 return queue_delayed_work_on(cpu, system_wq, dwork, delay);
592}
593
594/**
595 * schedule_delayed_work - put work task in global workqueue after delay
596 * @dwork: job to be done
597 * @delay: number of jiffies to wait or 0 for immediate execution
598 *
599 * After waiting for a given time this puts a job in the kernel-global
600 * workqueue.
601 */
602static inline bool schedule_delayed_work(struct delayed_work *dwork,
603 unsigned long delay)
604{
605 return queue_delayed_work(system_wq, dwork, delay);
606}
607
Rusty Russell2d3854a2008-11-05 13:39:10 +1100608#ifndef CONFIG_SMP
Tejun Heod84ff052013-03-12 11:29:59 -0700609static inline long work_on_cpu(int cpu, long (*fn)(void *), void *arg)
Rusty Russell2d3854a2008-11-05 13:39:10 +1100610{
611 return fn(arg);
612}
Thomas Gleixner0e8d6a92017-04-12 22:07:28 +0200613static inline long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg)
614{
615 return fn(arg);
616}
Rusty Russell2d3854a2008-11-05 13:39:10 +1100617#else
Tejun Heod84ff052013-03-12 11:29:59 -0700618long work_on_cpu(int cpu, long (*fn)(void *), void *arg);
Thomas Gleixner0e8d6a92017-04-12 22:07:28 +0200619long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg);
Rusty Russell2d3854a2008-11-05 13:39:10 +1100620#endif /* CONFIG_SMP */
Paul E. McKenneya25909a2010-05-13 12:32:28 -0700621
Tejun Heoa0a1a5f2010-06-29 10:07:12 +0200622#ifdef CONFIG_FREEZER
623extern void freeze_workqueues_begin(void);
624extern bool freeze_workqueues_busy(void);
625extern void thaw_workqueues(void);
626#endif /* CONFIG_FREEZER */
627
Tejun Heo226223a2013-03-12 11:30:05 -0700628#ifdef CONFIG_SYSFS
629int workqueue_sysfs_register(struct workqueue_struct *wq);
630#else /* CONFIG_SYSFS */
631static inline int workqueue_sysfs_register(struct workqueue_struct *wq)
632{ return 0; }
633#endif /* CONFIG_SYSFS */
634
Tejun Heo82607adc2015-12-08 11:28:04 -0500635#ifdef CONFIG_WQ_WATCHDOG
636void wq_watchdog_touch(int cpu);
637#else /* CONFIG_WQ_WATCHDOG */
638static inline void wq_watchdog_touch(int cpu) { }
639#endif /* CONFIG_WQ_WATCHDOG */
640
Thomas Gleixner7ee681b2016-07-13 17:16:29 +0000641#ifdef CONFIG_SMP
642int workqueue_prepare_cpu(unsigned int cpu);
643int workqueue_online_cpu(unsigned int cpu);
644int workqueue_offline_cpu(unsigned int cpu);
645#endif
646
Tejun Heo3347fa02016-09-16 15:49:32 -0400647int __init workqueue_init_early(void);
648int __init workqueue_init(void);
649
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650#endif