1b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */ 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * workqueue.h --- work queue handling for Linux. 41da177e4SLinus Torvalds */ 51da177e4SLinus Torvalds 61da177e4SLinus Torvalds #ifndef _LINUX_WORKQUEUE_H 71da177e4SLinus Torvalds #define _LINUX_WORKQUEUE_H 81da177e4SLinus Torvalds 91da177e4SLinus Torvalds #include <linux/timer.h> 101da177e4SLinus Torvalds #include <linux/linkage.h> 111da177e4SLinus Torvalds #include <linux/bitops.h> 124e6045f1SJohannes Berg #include <linux/lockdep.h> 137a22ad75STejun Heo #include <linux/threads.h> 1460063497SArun Sharma #include <linux/atomic.h> 157a4e344cSTejun Heo #include <linux/cpumask.h> 1605f0fe6bSTejun Heo #include <linux/rcupdate.h> 171da177e4SLinus Torvalds 181da177e4SLinus Torvalds struct workqueue_struct; 191da177e4SLinus Torvalds 2065f27f38SDavid Howells struct work_struct; 2165f27f38SDavid Howells typedef void (*work_func_t)(struct work_struct *work); 228c20feb6SKees Cook void delayed_work_timer_fn(struct timer_list *t); 236bb49e59SDavid Howells 24a08727baSLinus Torvalds /* 25a08727baSLinus Torvalds * The first word is the work queue pointer and the flags rolled into 26a08727baSLinus Torvalds * one 27a08727baSLinus Torvalds */ 28a08727baSLinus Torvalds #define work_data_bits(work) ((unsigned long *)(&(work)->data)) 29a08727baSLinus Torvalds 3022df02bbSTejun Heo enum { 3122df02bbSTejun Heo WORK_STRUCT_PENDING_BIT = 0, /* work item is pending execution */ 328a2e8e5dSTejun Heo WORK_STRUCT_DELAYED_BIT = 1, /* work item is delayed */ 33112202d9STejun Heo WORK_STRUCT_PWQ_BIT = 2, /* data points to pwq */ 348a2e8e5dSTejun Heo WORK_STRUCT_LINKED_BIT = 3, /* next work is linked to this one */ 3522df02bbSTejun Heo #ifdef CONFIG_DEBUG_OBJECTS_WORK 368a2e8e5dSTejun Heo WORK_STRUCT_STATIC_BIT = 4, /* static initializer (debugobjects) */ 378a2e8e5dSTejun Heo WORK_STRUCT_COLOR_SHIFT = 5, /* color for workqueue flushing */ 380f900049STejun Heo #else 398a2e8e5dSTejun Heo WORK_STRUCT_COLOR_SHIFT = 4, /* color for workqueue flushing */ 4022df02bbSTejun Heo #endif 4122df02bbSTejun Heo 4273f53c4aSTejun Heo WORK_STRUCT_COLOR_BITS = 4, 4373f53c4aSTejun Heo 4422df02bbSTejun Heo WORK_STRUCT_PENDING = 1 << WORK_STRUCT_PENDING_BIT, 458a2e8e5dSTejun Heo WORK_STRUCT_DELAYED = 1 << WORK_STRUCT_DELAYED_BIT, 46112202d9STejun Heo WORK_STRUCT_PWQ = 1 << WORK_STRUCT_PWQ_BIT, 47affee4b2STejun Heo WORK_STRUCT_LINKED = 1 << WORK_STRUCT_LINKED_BIT, 4822df02bbSTejun Heo #ifdef CONFIG_DEBUG_OBJECTS_WORK 4922df02bbSTejun Heo WORK_STRUCT_STATIC = 1 << WORK_STRUCT_STATIC_BIT, 5022df02bbSTejun Heo #else 5122df02bbSTejun Heo WORK_STRUCT_STATIC = 0, 5222df02bbSTejun Heo #endif 5322df02bbSTejun Heo 5473f53c4aSTejun Heo /* 5573f53c4aSTejun Heo * The last color is no color used for works which don't 5673f53c4aSTejun Heo * participate in workqueue flushing. 5773f53c4aSTejun Heo */ 5873f53c4aSTejun Heo WORK_NR_COLORS = (1 << WORK_STRUCT_COLOR_BITS) - 1, 5973f53c4aSTejun Heo WORK_NO_COLOR = WORK_NR_COLORS, 6073f53c4aSTejun Heo 6179bc251fSLai Jiangshan /* not bound to any CPU, prefer the local CPU */ 62f3421797STejun Heo WORK_CPU_UNBOUND = NR_CPUS, 63bdbc5dd7STejun Heo 6473f53c4aSTejun Heo /* 65112202d9STejun Heo * Reserve 7 bits off of pwq pointer w/ debugobjects turned off. 66112202d9STejun Heo * This makes pwqs aligned to 256 bytes and allows 15 workqueue 67112202d9STejun Heo * flush colors. 6873f53c4aSTejun Heo */ 6973f53c4aSTejun Heo WORK_STRUCT_FLAG_BITS = WORK_STRUCT_COLOR_SHIFT + 7073f53c4aSTejun Heo WORK_STRUCT_COLOR_BITS, 7173f53c4aSTejun Heo 72112202d9STejun Heo /* data contains off-queue information when !WORK_STRUCT_PWQ */ 7345d9550aSLai Jiangshan WORK_OFFQ_FLAG_BASE = WORK_STRUCT_COLOR_SHIFT, 74bbb68dfaSTejun Heo 758603e1b3STejun Heo __WORK_OFFQ_CANCELING = WORK_OFFQ_FLAG_BASE, 768603e1b3STejun Heo WORK_OFFQ_CANCELING = (1 << __WORK_OFFQ_CANCELING), 77bbb68dfaSTejun Heo 78715b06b8STejun Heo /* 79715b06b8STejun Heo * When a work item is off queue, its high bits point to the last 807c3eed5cSTejun Heo * pool it was on. Cap at 31 bits and use the highest number to 817c3eed5cSTejun Heo * indicate that no pool is associated. 82715b06b8STejun Heo */ 83bbb68dfaSTejun Heo WORK_OFFQ_FLAG_BITS = 1, 847c3eed5cSTejun Heo WORK_OFFQ_POOL_SHIFT = WORK_OFFQ_FLAG_BASE + WORK_OFFQ_FLAG_BITS, 857c3eed5cSTejun Heo WORK_OFFQ_LEFT = BITS_PER_LONG - WORK_OFFQ_POOL_SHIFT, 867c3eed5cSTejun Heo WORK_OFFQ_POOL_BITS = WORK_OFFQ_LEFT <= 31 ? WORK_OFFQ_LEFT : 31, 877c3eed5cSTejun Heo WORK_OFFQ_POOL_NONE = (1LU << WORK_OFFQ_POOL_BITS) - 1, 88b5490077STejun Heo 89b5490077STejun Heo /* convenience constants */ 900f900049STejun Heo WORK_STRUCT_FLAG_MASK = (1UL << WORK_STRUCT_FLAG_BITS) - 1, 9122df02bbSTejun Heo WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK, 927c3eed5cSTejun Heo WORK_STRUCT_NO_POOL = (unsigned long)WORK_OFFQ_POOL_NONE << WORK_OFFQ_POOL_SHIFT, 93dcd989cbSTejun Heo 94dcd989cbSTejun Heo /* bit mask for work_busy() return values */ 95dcd989cbSTejun Heo WORK_BUSY_PENDING = 1 << 0, 96dcd989cbSTejun Heo WORK_BUSY_RUNNING = 1 << 1, 973d1cb205STejun Heo 983d1cb205STejun Heo /* maximum string length for set_worker_desc() */ 993d1cb205STejun Heo WORKER_DESC_LEN = 24, 10022df02bbSTejun Heo }; 10122df02bbSTejun Heo 1021da177e4SLinus Torvalds struct work_struct { 103a08727baSLinus Torvalds atomic_long_t data; 1041da177e4SLinus Torvalds struct list_head entry; 1056bb49e59SDavid Howells work_func_t func; 1064e6045f1SJohannes Berg #ifdef CONFIG_LOCKDEP 1074e6045f1SJohannes Berg struct lockdep_map lockdep_map; 1084e6045f1SJohannes Berg #endif 10952bad64dSDavid Howells }; 11052bad64dSDavid Howells 111a45463cbSArnd Bergmann #define WORK_DATA_INIT() ATOMIC_LONG_INIT((unsigned long)WORK_STRUCT_NO_POOL) 1127a22ad75STejun Heo #define WORK_DATA_STATIC_INIT() \ 113a45463cbSArnd Bergmann ATOMIC_LONG_INIT((unsigned long)(WORK_STRUCT_NO_POOL | WORK_STRUCT_STATIC)) 114a08727baSLinus Torvalds 11552bad64dSDavid Howells struct delayed_work { 11652bad64dSDavid Howells struct work_struct work; 1171da177e4SLinus Torvalds struct timer_list timer; 11860c057bcSLai Jiangshan 11960c057bcSLai Jiangshan /* target workqueue and CPU ->timer uses to queue ->work */ 12060c057bcSLai Jiangshan struct workqueue_struct *wq; 1211265057fSTejun Heo int cpu; 1221da177e4SLinus Torvalds }; 1231da177e4SLinus Torvalds 12405f0fe6bSTejun Heo struct rcu_work { 12505f0fe6bSTejun Heo struct work_struct work; 12605f0fe6bSTejun Heo struct rcu_head rcu; 12705f0fe6bSTejun Heo 12805f0fe6bSTejun Heo /* target workqueue ->rcu uses to queue ->work */ 12905f0fe6bSTejun Heo struct workqueue_struct *wq; 13005f0fe6bSTejun Heo }; 13105f0fe6bSTejun Heo 13242412c3aSSilvio Fricke /** 13342412c3aSSilvio Fricke * struct workqueue_attrs - A struct for workqueue attributes. 134d55262c4STejun Heo * 13542412c3aSSilvio Fricke * This can be used to change attributes of an unbound workqueue. 1367a4e344cSTejun Heo */ 1377a4e344cSTejun Heo struct workqueue_attrs { 13842412c3aSSilvio Fricke /** 13942412c3aSSilvio Fricke * @nice: nice level 14042412c3aSSilvio Fricke */ 14142412c3aSSilvio Fricke int nice; 14242412c3aSSilvio Fricke 14342412c3aSSilvio Fricke /** 14442412c3aSSilvio Fricke * @cpumask: allowed CPUs 14542412c3aSSilvio Fricke */ 14642412c3aSSilvio Fricke cpumask_var_t cpumask; 14742412c3aSSilvio Fricke 14842412c3aSSilvio Fricke /** 14942412c3aSSilvio Fricke * @no_numa: disable NUMA affinity 15042412c3aSSilvio Fricke * 15142412c3aSSilvio Fricke * Unlike other fields, ``no_numa`` isn't a property of a worker_pool. It 15242412c3aSSilvio Fricke * only modifies how :c:func:`apply_workqueue_attrs` select pools and thus 15342412c3aSSilvio Fricke * doesn't participate in pool hash calculations or equality comparisons. 15442412c3aSSilvio Fricke */ 15542412c3aSSilvio Fricke bool no_numa; 1567a4e344cSTejun Heo }; 1577a4e344cSTejun Heo 158bf6aede7SJean Delvare static inline struct delayed_work *to_delayed_work(struct work_struct *work) 159bf6aede7SJean Delvare { 160bf6aede7SJean Delvare return container_of(work, struct delayed_work, work); 161bf6aede7SJean Delvare } 162bf6aede7SJean Delvare 16305f0fe6bSTejun Heo static inline struct rcu_work *to_rcu_work(struct work_struct *work) 16405f0fe6bSTejun Heo { 16505f0fe6bSTejun Heo return container_of(work, struct rcu_work, work); 16605f0fe6bSTejun Heo } 16705f0fe6bSTejun Heo 1681fa44ecaSJames Bottomley struct execute_work { 1691fa44ecaSJames Bottomley struct work_struct work; 1701fa44ecaSJames Bottomley }; 1711fa44ecaSJames Bottomley 1724e6045f1SJohannes Berg #ifdef CONFIG_LOCKDEP 1734e6045f1SJohannes Berg /* 1744e6045f1SJohannes Berg * NB: because we have to copy the lockdep_map, setting _key 1754e6045f1SJohannes Berg * here is required, otherwise it could get initialised to the 1764e6045f1SJohannes Berg * copy of the lockdep_map! 1774e6045f1SJohannes Berg */ 1784e6045f1SJohannes Berg #define __WORK_INIT_LOCKDEP_MAP(n, k) \ 1794e6045f1SJohannes Berg .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k), 1804e6045f1SJohannes Berg #else 1814e6045f1SJohannes Berg #define __WORK_INIT_LOCKDEP_MAP(n, k) 1824e6045f1SJohannes Berg #endif 1834e6045f1SJohannes Berg 18465f27f38SDavid Howells #define __WORK_INITIALIZER(n, f) { \ 185dc186ad7SThomas Gleixner .data = WORK_DATA_STATIC_INIT(), \ 18665f27f38SDavid Howells .entry = { &(n).entry, &(n).entry }, \ 18765f27f38SDavid Howells .func = (f), \ 1884e6045f1SJohannes Berg __WORK_INIT_LOCKDEP_MAP(#n, &(n)) \ 18965f27f38SDavid Howells } 19065f27f38SDavid Howells 191f991b318STejun Heo #define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \ 19265f27f38SDavid Howells .work = __WORK_INITIALIZER((n).work, (f)), \ 193841b86f3SKees Cook .timer = __TIMER_INITIALIZER(delayed_work_timer_fn,\ 194e0aecdd8STejun Heo (tflags) | TIMER_IRQSAFE), \ 195dd6414b5SPhil Carmody } 196dd6414b5SPhil Carmody 19765f27f38SDavid Howells #define DECLARE_WORK(n, f) \ 19865f27f38SDavid Howells struct work_struct n = __WORK_INITIALIZER(n, f) 19965f27f38SDavid Howells 20065f27f38SDavid Howells #define DECLARE_DELAYED_WORK(n, f) \ 201f991b318STejun Heo struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0) 20265f27f38SDavid Howells 203203b42f7STejun Heo #define DECLARE_DEFERRABLE_WORK(n, f) \ 204f991b318STejun Heo struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, TIMER_DEFERRABLE) 205dd6414b5SPhil Carmody 206dc186ad7SThomas Gleixner #ifdef CONFIG_DEBUG_OBJECTS_WORK 207dc186ad7SThomas Gleixner extern void __init_work(struct work_struct *work, int onstack); 208dc186ad7SThomas Gleixner extern void destroy_work_on_stack(struct work_struct *work); 209ea2e64f2SThomas Gleixner extern void destroy_delayed_work_on_stack(struct delayed_work *work); 2104690c4abSTejun Heo static inline unsigned int work_static(struct work_struct *work) 2114690c4abSTejun Heo { 21222df02bbSTejun Heo return *work_data_bits(work) & WORK_STRUCT_STATIC; 2134690c4abSTejun Heo } 214dc186ad7SThomas Gleixner #else 215dc186ad7SThomas Gleixner static inline void __init_work(struct work_struct *work, int onstack) { } 216dc186ad7SThomas Gleixner static inline void destroy_work_on_stack(struct work_struct *work) { } 217ea2e64f2SThomas Gleixner static inline void destroy_delayed_work_on_stack(struct delayed_work *work) { } 2184690c4abSTejun Heo static inline unsigned int work_static(struct work_struct *work) { return 0; } 219dc186ad7SThomas Gleixner #endif 220dc186ad7SThomas Gleixner 2211da177e4SLinus Torvalds /* 22252bad64dSDavid Howells * initialize all of a work item in one go 223a08727baSLinus Torvalds * 224b9049df5SDmitri Vorobiev * NOTE! No point in using "atomic_long_set()": using a direct 225a08727baSLinus Torvalds * assignment of the work data initializer allows the compiler 226a08727baSLinus Torvalds * to generate better code. 2271da177e4SLinus Torvalds */ 2284e6045f1SJohannes Berg #ifdef CONFIG_LOCKDEP 229dc186ad7SThomas Gleixner #define __INIT_WORK(_work, _func, _onstack) \ 2304e6045f1SJohannes Berg do { \ 2314e6045f1SJohannes Berg static struct lock_class_key __key; \ 2324e6045f1SJohannes Berg \ 233dc186ad7SThomas Gleixner __init_work((_work), _onstack); \ 2344e6045f1SJohannes Berg (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \ 235fd1a5b04SByungchul Park lockdep_init_map(&(_work)->lockdep_map, "(work_completion)"#_work, &__key, 0); \ 2364e6045f1SJohannes Berg INIT_LIST_HEAD(&(_work)->entry); \ 237f073f922STejun Heo (_work)->func = (_func); \ 2384e6045f1SJohannes Berg } while (0) 2394e6045f1SJohannes Berg #else 240dc186ad7SThomas Gleixner #define __INIT_WORK(_work, _func, _onstack) \ 2411da177e4SLinus Torvalds do { \ 242dc186ad7SThomas Gleixner __init_work((_work), _onstack); \ 24323b2e599SOleg Nesterov (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \ 24465f27f38SDavid Howells INIT_LIST_HEAD(&(_work)->entry); \ 245f073f922STejun Heo (_work)->func = (_func); \ 24665f27f38SDavid Howells } while (0) 2474e6045f1SJohannes Berg #endif 24865f27f38SDavid Howells 249dc186ad7SThomas Gleixner #define INIT_WORK(_work, _func) \ 2509da7dae9SValentin Rothberg __INIT_WORK((_work), (_func), 0) 251dc186ad7SThomas Gleixner 252ca1cab37SAndrew Morton #define INIT_WORK_ONSTACK(_work, _func) \ 2539da7dae9SValentin Rothberg __INIT_WORK((_work), (_func), 1) 254dc186ad7SThomas Gleixner 255f991b318STejun Heo #define __INIT_DELAYED_WORK(_work, _func, _tflags) \ 25665f27f38SDavid Howells do { \ 25765f27f38SDavid Howells INIT_WORK(&(_work)->work, (_func)); \ 258919b250fSKees Cook __init_timer(&(_work)->timer, \ 259919b250fSKees Cook delayed_work_timer_fn, \ 260e0aecdd8STejun Heo (_tflags) | TIMER_IRQSAFE); \ 26165f27f38SDavid Howells } while (0) 26265f27f38SDavid Howells 263f991b318STejun Heo #define __INIT_DELAYED_WORK_ONSTACK(_work, _func, _tflags) \ 2646d612b0fSPeter Zijlstra do { \ 265ca1cab37SAndrew Morton INIT_WORK_ONSTACK(&(_work)->work, (_func)); \ 266919b250fSKees Cook __init_timer_on_stack(&(_work)->timer, \ 267919b250fSKees Cook delayed_work_timer_fn, \ 268e0aecdd8STejun Heo (_tflags) | TIMER_IRQSAFE); \ 2696d612b0fSPeter Zijlstra } while (0) 2706d612b0fSPeter Zijlstra 271f991b318STejun Heo #define INIT_DELAYED_WORK(_work, _func) \ 272f991b318STejun Heo __INIT_DELAYED_WORK(_work, _func, 0) 273f991b318STejun Heo 274f991b318STejun Heo #define INIT_DELAYED_WORK_ONSTACK(_work, _func) \ 275f991b318STejun Heo __INIT_DELAYED_WORK_ONSTACK(_work, _func, 0) 276f991b318STejun Heo 277203b42f7STejun Heo #define INIT_DEFERRABLE_WORK(_work, _func) \ 278f991b318STejun Heo __INIT_DELAYED_WORK(_work, _func, TIMER_DEFERRABLE) 279f991b318STejun Heo 280f991b318STejun Heo #define INIT_DEFERRABLE_WORK_ONSTACK(_work, _func) \ 281f991b318STejun Heo __INIT_DELAYED_WORK_ONSTACK(_work, _func, TIMER_DEFERRABLE) 28228287033SVenki Pallipadi 28305f0fe6bSTejun Heo #define INIT_RCU_WORK(_work, _func) \ 28405f0fe6bSTejun Heo INIT_WORK(&(_work)->work, (_func)) 28505f0fe6bSTejun Heo 28605f0fe6bSTejun Heo #define INIT_RCU_WORK_ONSTACK(_work, _func) \ 28705f0fe6bSTejun Heo INIT_WORK_ONSTACK(&(_work)->work, (_func)) 28805f0fe6bSTejun Heo 289365970a1SDavid Howells /** 290365970a1SDavid Howells * work_pending - Find out whether a work item is currently pending 291365970a1SDavid Howells * @work: The work item in question 292365970a1SDavid Howells */ 293365970a1SDavid Howells #define work_pending(work) \ 29422df02bbSTejun Heo test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work)) 295365970a1SDavid Howells 296365970a1SDavid Howells /** 297365970a1SDavid Howells * delayed_work_pending - Find out whether a delayable work item is currently 298365970a1SDavid Howells * pending 299355c0663SJonathan Corbet * @w: The work item in question 300365970a1SDavid Howells */ 3010221872aSLinus Torvalds #define delayed_work_pending(w) \ 3020221872aSLinus Torvalds work_pending(&(w)->work) 303365970a1SDavid Howells 304c54fce6eSTejun Heo /* 305c54fce6eSTejun Heo * Workqueue flags and constants. For details, please refer to 30642412c3aSSilvio Fricke * Documentation/core-api/workqueue.rst. 307c54fce6eSTejun Heo */ 30897e37d7bSTejun Heo enum { 309c7fc77f7STejun Heo WQ_UNBOUND = 1 << 1, /* not bound to any cpu */ 31058a69cb4STejun Heo WQ_FREEZABLE = 1 << 2, /* freeze during suspend */ 3116370a6adSTejun Heo WQ_MEM_RECLAIM = 1 << 3, /* may be used for memory reclaim */ 312649027d7STejun Heo WQ_HIGHPRI = 1 << 4, /* high priority */ 31341f50094SGeert Uytterhoeven WQ_CPU_INTENSIVE = 1 << 5, /* cpu intensive workqueue */ 314226223abSTejun Heo WQ_SYSFS = 1 << 6, /* visible in sysfs, see wq_sysfs_register() */ 315b71ab8c2STejun Heo 316cee22a15SViresh Kumar /* 317cee22a15SViresh Kumar * Per-cpu workqueues are generally preferred because they tend to 318cee22a15SViresh Kumar * show better performance thanks to cache locality. Per-cpu 319cee22a15SViresh Kumar * workqueues exclude the scheduler from choosing the CPU to 320cee22a15SViresh Kumar * execute the worker threads, which has an unfortunate side effect 321cee22a15SViresh Kumar * of increasing power consumption. 322cee22a15SViresh Kumar * 323cee22a15SViresh Kumar * The scheduler considers a CPU idle if it doesn't have any task 324cee22a15SViresh Kumar * to execute and tries to keep idle cores idle to conserve power; 325cee22a15SViresh Kumar * however, for example, a per-cpu work item scheduled from an 326cee22a15SViresh Kumar * interrupt handler on an idle CPU will force the scheduler to 327cee22a15SViresh Kumar * excute the work item on that CPU breaking the idleness, which in 328cee22a15SViresh Kumar * turn may lead to more scheduling choices which are sub-optimal 329cee22a15SViresh Kumar * in terms of power consumption. 330cee22a15SViresh Kumar * 331cee22a15SViresh Kumar * Workqueues marked with WQ_POWER_EFFICIENT are per-cpu by default 332cee22a15SViresh Kumar * but become unbound if workqueue.power_efficient kernel param is 333cee22a15SViresh Kumar * specified. Per-cpu workqueues which are identified to 334cee22a15SViresh Kumar * contribute significantly to power-consumption are identified and 335cee22a15SViresh Kumar * marked with this flag and enabling the power_efficient mode 336cee22a15SViresh Kumar * leads to noticeable power saving at the cost of small 337cee22a15SViresh Kumar * performance disadvantage. 338cee22a15SViresh Kumar * 339cee22a15SViresh Kumar * http://thread.gmane.org/gmane.linux.kernel/1480396 340cee22a15SViresh Kumar */ 341cee22a15SViresh Kumar WQ_POWER_EFFICIENT = 1 << 7, 342cee22a15SViresh Kumar 343618b01ebSTejun Heo __WQ_DRAINING = 1 << 16, /* internal: workqueue is draining */ 3448719dceaSTejun Heo __WQ_ORDERED = 1 << 17, /* internal: workqueue is ordered */ 34523d11a58STejun Heo __WQ_LEGACY = 1 << 18, /* internal: create*_workqueue() */ 346fbf1c41fSBen Hutchings __WQ_ORDERED_EXPLICIT = 1 << 19, /* internal: alloc_ordered_workqueue() */ 347e41e704bSTejun Heo 348b71ab8c2STejun Heo WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */ 349f3421797STejun Heo WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */ 350b71ab8c2STejun Heo WQ_DFL_ACTIVE = WQ_MAX_ACTIVE / 2, 35197e37d7bSTejun Heo }; 35252bad64dSDavid Howells 353f3421797STejun Heo /* unbound wq's aren't per-cpu, scale max_active according to #cpus */ 354f3421797STejun Heo #define WQ_UNBOUND_MAX_ACTIVE \ 355f3421797STejun Heo max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU) 356f3421797STejun Heo 357d320c038STejun Heo /* 358d320c038STejun Heo * System-wide workqueues which are always present. 359d320c038STejun Heo * 360d320c038STejun Heo * system_wq is the one used by schedule[_delayed]_work[_on](). 361d320c038STejun Heo * Multi-CPU multi-threaded. There are users which expect relatively 362d320c038STejun Heo * short queue flush time. Don't queue works which can run for too 363d320c038STejun Heo * long. 364d320c038STejun Heo * 36573e43544SLai Jiangshan * system_highpri_wq is similar to system_wq but for work items which 36673e43544SLai Jiangshan * require WQ_HIGHPRI. 36773e43544SLai Jiangshan * 368d320c038STejun Heo * system_long_wq is similar to system_wq but may host long running 369d320c038STejun Heo * works. Queue flushing might take relatively long. 370d320c038STejun Heo * 371f3421797STejun Heo * system_unbound_wq is unbound workqueue. Workers are not bound to 372f3421797STejun Heo * any specific CPU, not concurrency managed, and all queued works are 373f3421797STejun Heo * executed immediately as long as max_active limit is not reached and 374f3421797STejun Heo * resources are available. 3754149efb2STejun Heo * 37624d51addSTejun Heo * system_freezable_wq is equivalent to system_wq except that it's 37724d51addSTejun Heo * freezable. 3780668106cSViresh Kumar * 3790668106cSViresh Kumar * *_power_efficient_wq are inclined towards saving power and converted 3800668106cSViresh Kumar * into WQ_UNBOUND variants if 'wq_power_efficient' is enabled; otherwise, 3810668106cSViresh Kumar * they are same as their non-power-efficient counterparts - e.g. 3820668106cSViresh Kumar * system_power_efficient_wq is identical to system_wq if 3830668106cSViresh Kumar * 'wq_power_efficient' is disabled. See WQ_POWER_EFFICIENT for more info. 384d320c038STejun Heo */ 385d320c038STejun Heo extern struct workqueue_struct *system_wq; 38673e43544SLai Jiangshan extern struct workqueue_struct *system_highpri_wq; 387d320c038STejun Heo extern struct workqueue_struct *system_long_wq; 388f3421797STejun Heo extern struct workqueue_struct *system_unbound_wq; 38924d51addSTejun Heo extern struct workqueue_struct *system_freezable_wq; 3900668106cSViresh Kumar extern struct workqueue_struct *system_power_efficient_wq; 3910668106cSViresh Kumar extern struct workqueue_struct *system_freezable_power_efficient_wq; 392ae930e0fSTejun Heo 393b196be89STejun Heo /** 394b196be89STejun Heo * alloc_workqueue - allocate a workqueue 395b196be89STejun Heo * @fmt: printf format for the name of the workqueue 396b196be89STejun Heo * @flags: WQ_* flags 397b196be89STejun Heo * @max_active: max in-flight work items, 0 for default 398669de8bdSBart Van Assche * remaining args: args for @fmt 399b196be89STejun Heo * 400b196be89STejun Heo * Allocate a workqueue with the specified parameters. For detailed 40142412c3aSSilvio Fricke * information on WQ_* flags, please refer to 40242412c3aSSilvio Fricke * Documentation/core-api/workqueue.rst. 403b196be89STejun Heo * 404b196be89STejun Heo * RETURNS: 405b196be89STejun Heo * Pointer to the allocated workqueue on success, %NULL on failure. 406b196be89STejun Heo */ 407669de8bdSBart Van Assche struct workqueue_struct *alloc_workqueue(const char *fmt, 408669de8bdSBart Van Assche unsigned int flags, 409669de8bdSBart Van Assche int max_active, ...); 4104e6045f1SJohannes Berg 41181dcaf65STejun Heo /** 41281dcaf65STejun Heo * alloc_ordered_workqueue - allocate an ordered workqueue 413b196be89STejun Heo * @fmt: printf format for the name of the workqueue 41458a69cb4STejun Heo * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful) 415355c0663SJonathan Corbet * @args...: args for @fmt 41681dcaf65STejun Heo * 41781dcaf65STejun Heo * Allocate an ordered workqueue. An ordered workqueue executes at 41881dcaf65STejun Heo * most one work item at any given time in the queued order. They are 41981dcaf65STejun Heo * implemented as unbound workqueues with @max_active of one. 42081dcaf65STejun Heo * 42181dcaf65STejun Heo * RETURNS: 42281dcaf65STejun Heo * Pointer to the allocated workqueue on success, %NULL on failure. 42381dcaf65STejun Heo */ 424b196be89STejun Heo #define alloc_ordered_workqueue(fmt, flags, args...) \ 4250a94efb5STejun Heo alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | \ 4260a94efb5STejun Heo __WQ_ORDERED_EXPLICIT | (flags), 1, ##args) 42781dcaf65STejun Heo 42897e37d7bSTejun Heo #define create_workqueue(name) \ 42923d11a58STejun Heo alloc_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, 1, (name)) 43058a69cb4STejun Heo #define create_freezable_workqueue(name) \ 43123d11a58STejun Heo alloc_workqueue("%s", __WQ_LEGACY | WQ_FREEZABLE | WQ_UNBOUND | \ 43223d11a58STejun Heo WQ_MEM_RECLAIM, 1, (name)) 43397e37d7bSTejun Heo #define create_singlethread_workqueue(name) \ 43423d11a58STejun Heo alloc_ordered_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, name) 4351da177e4SLinus Torvalds 4361da177e4SLinus Torvalds extern void destroy_workqueue(struct workqueue_struct *wq); 4371da177e4SLinus Torvalds 438513c98d0SDaniel Jordan struct workqueue_attrs *alloc_workqueue_attrs(void); 439513c98d0SDaniel Jordan void free_workqueue_attrs(struct workqueue_attrs *attrs); 440513c98d0SDaniel Jordan int apply_workqueue_attrs(struct workqueue_struct *wq, 441513c98d0SDaniel Jordan const struct workqueue_attrs *attrs); 442042f7df1SLai Jiangshan int workqueue_set_unbound_cpumask(cpumask_var_t cpumask); 4437a4e344cSTejun Heo 444d4283e93STejun Heo extern bool queue_work_on(int cpu, struct workqueue_struct *wq, 445c1a220e7SZhang Rui struct work_struct *work); 4468204e0c1SAlexander Duyck extern bool queue_work_node(int node, struct workqueue_struct *wq, 4478204e0c1SAlexander Duyck struct work_struct *work); 448d4283e93STejun Heo extern bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq, 44952bad64dSDavid Howells struct delayed_work *work, unsigned long delay); 4508376fe22STejun Heo extern bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq, 4518376fe22STejun Heo struct delayed_work *dwork, unsigned long delay); 45205f0fe6bSTejun Heo extern bool queue_rcu_work(struct workqueue_struct *wq, struct rcu_work *rwork); 45328e53bddSOleg Nesterov 454b3c97528SHarvey Harrison extern void flush_workqueue(struct workqueue_struct *wq); 4559c5a2ba7STejun Heo extern void drain_workqueue(struct workqueue_struct *wq); 4561da177e4SLinus Torvalds 45765f27f38SDavid Howells extern int schedule_on_each_cpu(work_func_t func); 4581da177e4SLinus Torvalds 45965f27f38SDavid Howells int execute_in_process_context(work_func_t fn, struct execute_work *); 4601da177e4SLinus Torvalds 461401a8d04STejun Heo extern bool flush_work(struct work_struct *work); 462401a8d04STejun Heo extern bool cancel_work_sync(struct work_struct *work); 463401a8d04STejun Heo 464401a8d04STejun Heo extern bool flush_delayed_work(struct delayed_work *dwork); 46557b30ae7STejun Heo extern bool cancel_delayed_work(struct delayed_work *dwork); 466401a8d04STejun Heo extern bool cancel_delayed_work_sync(struct delayed_work *dwork); 46728e53bddSOleg Nesterov 46805f0fe6bSTejun Heo extern bool flush_rcu_work(struct rcu_work *rwork); 46905f0fe6bSTejun Heo 470dcd989cbSTejun Heo extern void workqueue_set_max_active(struct workqueue_struct *wq, 471dcd989cbSTejun Heo int max_active); 47227d4ee03SLukas Wunner extern struct work_struct *current_work(void); 473e6267616STejun Heo extern bool current_is_workqueue_rescuer(void); 474d84ff051STejun Heo extern bool workqueue_congested(int cpu, struct workqueue_struct *wq); 475dcd989cbSTejun Heo extern unsigned int work_busy(struct work_struct *work); 4763d1cb205STejun Heo extern __printf(1, 2) void set_worker_desc(const char *fmt, ...); 4773d1cb205STejun Heo extern void print_worker_info(const char *log_lvl, struct task_struct *task); 4783494fc30STejun Heo extern void show_workqueue_state(void); 4796b59808bSTejun Heo extern void wq_worker_comm(char *buf, size_t size, struct task_struct *task); 480dcd989cbSTejun Heo 4818425e3d5STejun Heo /** 4828425e3d5STejun Heo * queue_work - queue work on a workqueue 4838425e3d5STejun Heo * @wq: workqueue to use 4848425e3d5STejun Heo * @work: work to queue 4858425e3d5STejun Heo * 4868425e3d5STejun Heo * Returns %false if @work was already on a queue, %true otherwise. 4878425e3d5STejun Heo * 4888425e3d5STejun Heo * We queue the work to the CPU on which it was submitted, but if the CPU dies 4898425e3d5STejun Heo * it can be processed by another CPU. 490dbb92f88SAndrea Parri * 491dbb92f88SAndrea Parri * Memory-ordering properties: If it returns %true, guarantees that all stores 492dbb92f88SAndrea Parri * preceding the call to queue_work() in the program order will be visible from 493dbb92f88SAndrea Parri * the CPU which will execute @work by the time such work executes, e.g., 494dbb92f88SAndrea Parri * 495dbb92f88SAndrea Parri * { x is initially 0 } 496dbb92f88SAndrea Parri * 497dbb92f88SAndrea Parri * CPU0 CPU1 498dbb92f88SAndrea Parri * 499dbb92f88SAndrea Parri * WRITE_ONCE(x, 1); [ @work is being executed ] 500dbb92f88SAndrea Parri * r0 = queue_work(wq, work); r1 = READ_ONCE(x); 501dbb92f88SAndrea Parri * 502dbb92f88SAndrea Parri * Forbids: r0 == true && r1 == 0 5038425e3d5STejun Heo */ 5048425e3d5STejun Heo static inline bool queue_work(struct workqueue_struct *wq, 5058425e3d5STejun Heo struct work_struct *work) 5068425e3d5STejun Heo { 5078425e3d5STejun Heo return queue_work_on(WORK_CPU_UNBOUND, wq, work); 5088425e3d5STejun Heo } 5098425e3d5STejun Heo 5108425e3d5STejun Heo /** 5118425e3d5STejun Heo * queue_delayed_work - queue work on a workqueue after delay 5128425e3d5STejun Heo * @wq: workqueue to use 5138425e3d5STejun Heo * @dwork: delayable work to queue 5148425e3d5STejun Heo * @delay: number of jiffies to wait before queueing 5158425e3d5STejun Heo * 5168425e3d5STejun Heo * Equivalent to queue_delayed_work_on() but tries to use the local CPU. 5178425e3d5STejun Heo */ 5188425e3d5STejun Heo static inline bool queue_delayed_work(struct workqueue_struct *wq, 5198425e3d5STejun Heo struct delayed_work *dwork, 5208425e3d5STejun Heo unsigned long delay) 5218425e3d5STejun Heo { 5228425e3d5STejun Heo return queue_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay); 5238425e3d5STejun Heo } 5248425e3d5STejun Heo 5258425e3d5STejun Heo /** 5268425e3d5STejun Heo * mod_delayed_work - modify delay of or queue a delayed work 5278425e3d5STejun Heo * @wq: workqueue to use 5288425e3d5STejun Heo * @dwork: work to queue 5298425e3d5STejun Heo * @delay: number of jiffies to wait before queueing 5308425e3d5STejun Heo * 5318425e3d5STejun Heo * mod_delayed_work_on() on local CPU. 5328425e3d5STejun Heo */ 5338425e3d5STejun Heo static inline bool mod_delayed_work(struct workqueue_struct *wq, 5348425e3d5STejun Heo struct delayed_work *dwork, 5358425e3d5STejun Heo unsigned long delay) 5368425e3d5STejun Heo { 5378425e3d5STejun Heo return mod_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay); 5388425e3d5STejun Heo } 5398425e3d5STejun Heo 5408425e3d5STejun Heo /** 5418425e3d5STejun Heo * schedule_work_on - put work task on a specific cpu 5428425e3d5STejun Heo * @cpu: cpu to put the work task on 5438425e3d5STejun Heo * @work: job to be done 5448425e3d5STejun Heo * 5458425e3d5STejun Heo * This puts a job on a specific cpu 5468425e3d5STejun Heo */ 5478425e3d5STejun Heo static inline bool schedule_work_on(int cpu, struct work_struct *work) 5488425e3d5STejun Heo { 5498425e3d5STejun Heo return queue_work_on(cpu, system_wq, work); 5508425e3d5STejun Heo } 5518425e3d5STejun Heo 5528425e3d5STejun Heo /** 5538425e3d5STejun Heo * schedule_work - put work task in global workqueue 5548425e3d5STejun Heo * @work: job to be done 5558425e3d5STejun Heo * 5568425e3d5STejun Heo * Returns %false if @work was already on the kernel-global workqueue and 5578425e3d5STejun Heo * %true otherwise. 5588425e3d5STejun Heo * 5598425e3d5STejun Heo * This puts a job in the kernel-global workqueue if it was not already 5608425e3d5STejun Heo * queued and leaves it in the same position on the kernel-global 5618425e3d5STejun Heo * workqueue otherwise. 562dbb92f88SAndrea Parri * 563dbb92f88SAndrea Parri * Shares the same memory-ordering properties of queue_work(), cf. the 564dbb92f88SAndrea Parri * DocBook header of queue_work(). 5658425e3d5STejun Heo */ 5668425e3d5STejun Heo static inline bool schedule_work(struct work_struct *work) 5678425e3d5STejun Heo { 5688425e3d5STejun Heo return queue_work(system_wq, work); 5698425e3d5STejun Heo } 5708425e3d5STejun Heo 5718425e3d5STejun Heo /** 57237b1ef31SLai Jiangshan * flush_scheduled_work - ensure that any scheduled work has run to completion. 57337b1ef31SLai Jiangshan * 57437b1ef31SLai Jiangshan * Forces execution of the kernel-global workqueue and blocks until its 57537b1ef31SLai Jiangshan * completion. 57637b1ef31SLai Jiangshan * 57737b1ef31SLai Jiangshan * Think twice before calling this function! It's very easy to get into 57837b1ef31SLai Jiangshan * trouble if you don't take great care. Either of the following situations 57937b1ef31SLai Jiangshan * will lead to deadlock: 58037b1ef31SLai Jiangshan * 58137b1ef31SLai Jiangshan * One of the work items currently on the workqueue needs to acquire 58237b1ef31SLai Jiangshan * a lock held by your code or its caller. 58337b1ef31SLai Jiangshan * 58437b1ef31SLai Jiangshan * Your code is running in the context of a work routine. 58537b1ef31SLai Jiangshan * 58637b1ef31SLai Jiangshan * They will be detected by lockdep when they occur, but the first might not 58737b1ef31SLai Jiangshan * occur very often. It depends on what work items are on the workqueue and 58837b1ef31SLai Jiangshan * what locks they need, which you have no control over. 58937b1ef31SLai Jiangshan * 59037b1ef31SLai Jiangshan * In most situations flushing the entire workqueue is overkill; you merely 59137b1ef31SLai Jiangshan * need to know that a particular work item isn't queued and isn't running. 59237b1ef31SLai Jiangshan * In such cases you should use cancel_delayed_work_sync() or 59337b1ef31SLai Jiangshan * cancel_work_sync() instead. 59437b1ef31SLai Jiangshan */ 59537b1ef31SLai Jiangshan static inline void flush_scheduled_work(void) 59637b1ef31SLai Jiangshan { 59737b1ef31SLai Jiangshan flush_workqueue(system_wq); 59837b1ef31SLai Jiangshan } 59937b1ef31SLai Jiangshan 60037b1ef31SLai Jiangshan /** 6018425e3d5STejun Heo * schedule_delayed_work_on - queue work in global workqueue on CPU after delay 6028425e3d5STejun Heo * @cpu: cpu to use 6038425e3d5STejun Heo * @dwork: job to be done 6048425e3d5STejun Heo * @delay: number of jiffies to wait 6058425e3d5STejun Heo * 6068425e3d5STejun Heo * After waiting for a given time this puts a job in the kernel-global 6078425e3d5STejun Heo * workqueue on the specified CPU. 6088425e3d5STejun Heo */ 6098425e3d5STejun Heo static inline bool schedule_delayed_work_on(int cpu, struct delayed_work *dwork, 6108425e3d5STejun Heo unsigned long delay) 6118425e3d5STejun Heo { 6128425e3d5STejun Heo return queue_delayed_work_on(cpu, system_wq, dwork, delay); 6138425e3d5STejun Heo } 6148425e3d5STejun Heo 6158425e3d5STejun Heo /** 6168425e3d5STejun Heo * schedule_delayed_work - put work task in global workqueue after delay 6178425e3d5STejun Heo * @dwork: job to be done 6188425e3d5STejun Heo * @delay: number of jiffies to wait or 0 for immediate execution 6198425e3d5STejun Heo * 6208425e3d5STejun Heo * After waiting for a given time this puts a job in the kernel-global 6218425e3d5STejun Heo * workqueue. 6228425e3d5STejun Heo */ 6238425e3d5STejun Heo static inline bool schedule_delayed_work(struct delayed_work *dwork, 6248425e3d5STejun Heo unsigned long delay) 6258425e3d5STejun Heo { 6268425e3d5STejun Heo return queue_delayed_work(system_wq, dwork, delay); 6278425e3d5STejun Heo } 6288425e3d5STejun Heo 6292d3854a3SRusty Russell #ifndef CONFIG_SMP 630d84ff051STejun Heo static inline long work_on_cpu(int cpu, long (*fn)(void *), void *arg) 6312d3854a3SRusty Russell { 6322d3854a3SRusty Russell return fn(arg); 6332d3854a3SRusty Russell } 6340e8d6a93SThomas Gleixner static inline long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg) 6350e8d6a93SThomas Gleixner { 6360e8d6a93SThomas Gleixner return fn(arg); 6370e8d6a93SThomas Gleixner } 6382d3854a3SRusty Russell #else 639d84ff051STejun Heo long work_on_cpu(int cpu, long (*fn)(void *), void *arg); 6400e8d6a93SThomas Gleixner long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg); 6412d3854a3SRusty Russell #endif /* CONFIG_SMP */ 642a25909a4SPaul E. McKenney 643a0a1a5fdSTejun Heo #ifdef CONFIG_FREEZER 644a0a1a5fdSTejun Heo extern void freeze_workqueues_begin(void); 645a0a1a5fdSTejun Heo extern bool freeze_workqueues_busy(void); 646a0a1a5fdSTejun Heo extern void thaw_workqueues(void); 647a0a1a5fdSTejun Heo #endif /* CONFIG_FREEZER */ 648a0a1a5fdSTejun Heo 649226223abSTejun Heo #ifdef CONFIG_SYSFS 650226223abSTejun Heo int workqueue_sysfs_register(struct workqueue_struct *wq); 651226223abSTejun Heo #else /* CONFIG_SYSFS */ 652226223abSTejun Heo static inline int workqueue_sysfs_register(struct workqueue_struct *wq) 653226223abSTejun Heo { return 0; } 654226223abSTejun Heo #endif /* CONFIG_SYSFS */ 655226223abSTejun Heo 65682607adcSTejun Heo #ifdef CONFIG_WQ_WATCHDOG 65782607adcSTejun Heo void wq_watchdog_touch(int cpu); 65882607adcSTejun Heo #else /* CONFIG_WQ_WATCHDOG */ 65982607adcSTejun Heo static inline void wq_watchdog_touch(int cpu) { } 66082607adcSTejun Heo #endif /* CONFIG_WQ_WATCHDOG */ 66182607adcSTejun Heo 6627ee681b2SThomas Gleixner #ifdef CONFIG_SMP 6637ee681b2SThomas Gleixner int workqueue_prepare_cpu(unsigned int cpu); 6647ee681b2SThomas Gleixner int workqueue_online_cpu(unsigned int cpu); 6657ee681b2SThomas Gleixner int workqueue_offline_cpu(unsigned int cpu); 6667ee681b2SThomas Gleixner #endif 6677ee681b2SThomas Gleixner 6683347fa09STejun Heo int __init workqueue_init_early(void); 6693347fa09STejun Heo int __init workqueue_init(void); 6703347fa09STejun Heo 6711da177e4SLinus Torvalds #endif 672