Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/kernel/workqueue.c |
| 3 | * |
| 4 | * Generic mechanism for defining kernel helper threads for running |
| 5 | * arbitrary tasks in process context. |
| 6 | * |
| 7 | * Started by Ingo Molnar, Copyright (C) 2002 |
| 8 | * |
| 9 | * Derived from the taskqueue/keventd code by: |
| 10 | * |
| 11 | * David Woodhouse <dwmw2@infradead.org> |
Francois Cami | e1f8e87 | 2008-10-15 22:01:59 -0700 | [diff] [blame] | 12 | * Andrew Morton |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | * Kai Petzke <wpp@marie.physik.tu-berlin.de> |
| 14 | * Theodore Ts'o <tytso@mit.edu> |
Christoph Lameter | 89ada67 | 2005-10-30 15:01:59 -0800 | [diff] [blame] | 15 | * |
Christoph Lameter | cde5353 | 2008-07-04 09:59:22 -0700 | [diff] [blame] | 16 | * Made to use alloc_percpu by Christoph Lameter. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | */ |
| 18 | |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/kernel.h> |
| 21 | #include <linux/sched.h> |
| 22 | #include <linux/init.h> |
| 23 | #include <linux/signal.h> |
| 24 | #include <linux/completion.h> |
| 25 | #include <linux/workqueue.h> |
| 26 | #include <linux/slab.h> |
| 27 | #include <linux/cpu.h> |
| 28 | #include <linux/notifier.h> |
| 29 | #include <linux/kthread.h> |
James Bottomley | 1fa44ec | 2006-02-23 12:43:43 -0600 | [diff] [blame] | 30 | #include <linux/hardirq.h> |
Christoph Lameter | 4693402 | 2006-10-11 01:21:26 -0700 | [diff] [blame] | 31 | #include <linux/mempolicy.h> |
Rafael J. Wysocki | 341a595 | 2006-12-06 20:34:49 -0800 | [diff] [blame] | 32 | #include <linux/freezer.h> |
Peter Zijlstra | d5abe66 | 2006-12-06 20:37:26 -0800 | [diff] [blame] | 33 | #include <linux/kallsyms.h> |
| 34 | #include <linux/debug_locks.h> |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 35 | #include <linux/lockdep.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | |
| 37 | /* |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 38 | * Structure fields follow one of the following exclusion rules. |
| 39 | * |
| 40 | * I: Set during initialization and read-only afterwards. |
| 41 | * |
| 42 | * L: cwq->lock protected. Access with cwq->lock held. |
| 43 | * |
| 44 | * W: workqueue_lock protected. |
| 45 | */ |
| 46 | |
| 47 | /* |
Nathan Lynch | f756d5e | 2006-01-08 01:05:12 -0800 | [diff] [blame] | 48 | * The per-CPU workqueue (if single thread, we always use the first |
| 49 | * possible cpu). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | */ |
| 51 | struct cpu_workqueue_struct { |
| 52 | |
| 53 | spinlock_t lock; |
| 54 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | struct list_head worklist; |
| 56 | wait_queue_head_t more_work; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 57 | struct work_struct *current_work; |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 58 | unsigned int cpu; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 60 | struct workqueue_struct *wq; /* I: the owning workqueue */ |
| 61 | struct task_struct *thread; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | } ____cacheline_aligned; |
| 63 | |
| 64 | /* |
| 65 | * The externally visible workqueue abstraction is an array of |
| 66 | * per-CPU workqueues: |
| 67 | */ |
| 68 | struct workqueue_struct { |
Tejun Heo | 97e37d7 | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 69 | unsigned int flags; /* I: WQ_* flags */ |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 70 | struct cpu_workqueue_struct *cpu_wq; /* I: cwq's */ |
| 71 | struct list_head list; /* W: list of all workqueues */ |
| 72 | const char *name; /* I: workqueue name */ |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 73 | #ifdef CONFIG_LOCKDEP |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 74 | struct lockdep_map lockdep_map; |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 75 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | }; |
| 77 | |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 78 | #ifdef CONFIG_DEBUG_OBJECTS_WORK |
| 79 | |
| 80 | static struct debug_obj_descr work_debug_descr; |
| 81 | |
| 82 | /* |
| 83 | * fixup_init is called when: |
| 84 | * - an active object is initialized |
| 85 | */ |
| 86 | static int work_fixup_init(void *addr, enum debug_obj_state state) |
| 87 | { |
| 88 | struct work_struct *work = addr; |
| 89 | |
| 90 | switch (state) { |
| 91 | case ODEBUG_STATE_ACTIVE: |
| 92 | cancel_work_sync(work); |
| 93 | debug_object_init(work, &work_debug_descr); |
| 94 | return 1; |
| 95 | default: |
| 96 | return 0; |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | /* |
| 101 | * fixup_activate is called when: |
| 102 | * - an active object is activated |
| 103 | * - an unknown object is activated (might be a statically initialized object) |
| 104 | */ |
| 105 | static int work_fixup_activate(void *addr, enum debug_obj_state state) |
| 106 | { |
| 107 | struct work_struct *work = addr; |
| 108 | |
| 109 | switch (state) { |
| 110 | |
| 111 | case ODEBUG_STATE_NOTAVAILABLE: |
| 112 | /* |
| 113 | * This is not really a fixup. The work struct was |
| 114 | * statically initialized. We just make sure that it |
| 115 | * is tracked in the object tracker. |
| 116 | */ |
Tejun Heo | 22df02b | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 117 | if (test_bit(WORK_STRUCT_STATIC_BIT, work_data_bits(work))) { |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 118 | debug_object_init(work, &work_debug_descr); |
| 119 | debug_object_activate(work, &work_debug_descr); |
| 120 | return 0; |
| 121 | } |
| 122 | WARN_ON_ONCE(1); |
| 123 | return 0; |
| 124 | |
| 125 | case ODEBUG_STATE_ACTIVE: |
| 126 | WARN_ON(1); |
| 127 | |
| 128 | default: |
| 129 | return 0; |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | /* |
| 134 | * fixup_free is called when: |
| 135 | * - an active object is freed |
| 136 | */ |
| 137 | static int work_fixup_free(void *addr, enum debug_obj_state state) |
| 138 | { |
| 139 | struct work_struct *work = addr; |
| 140 | |
| 141 | switch (state) { |
| 142 | case ODEBUG_STATE_ACTIVE: |
| 143 | cancel_work_sync(work); |
| 144 | debug_object_free(work, &work_debug_descr); |
| 145 | return 1; |
| 146 | default: |
| 147 | return 0; |
| 148 | } |
| 149 | } |
| 150 | |
| 151 | static struct debug_obj_descr work_debug_descr = { |
| 152 | .name = "work_struct", |
| 153 | .fixup_init = work_fixup_init, |
| 154 | .fixup_activate = work_fixup_activate, |
| 155 | .fixup_free = work_fixup_free, |
| 156 | }; |
| 157 | |
| 158 | static inline void debug_work_activate(struct work_struct *work) |
| 159 | { |
| 160 | debug_object_activate(work, &work_debug_descr); |
| 161 | } |
| 162 | |
| 163 | static inline void debug_work_deactivate(struct work_struct *work) |
| 164 | { |
| 165 | debug_object_deactivate(work, &work_debug_descr); |
| 166 | } |
| 167 | |
| 168 | void __init_work(struct work_struct *work, int onstack) |
| 169 | { |
| 170 | if (onstack) |
| 171 | debug_object_init_on_stack(work, &work_debug_descr); |
| 172 | else |
| 173 | debug_object_init(work, &work_debug_descr); |
| 174 | } |
| 175 | EXPORT_SYMBOL_GPL(__init_work); |
| 176 | |
| 177 | void destroy_work_on_stack(struct work_struct *work) |
| 178 | { |
| 179 | debug_object_free(work, &work_debug_descr); |
| 180 | } |
| 181 | EXPORT_SYMBOL_GPL(destroy_work_on_stack); |
| 182 | |
| 183 | #else |
| 184 | static inline void debug_work_activate(struct work_struct *work) { } |
| 185 | static inline void debug_work_deactivate(struct work_struct *work) { } |
| 186 | #endif |
| 187 | |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 188 | /* Serializes the accesses to the list of workqueues. */ |
| 189 | static DEFINE_SPINLOCK(workqueue_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | static LIST_HEAD(workqueues); |
| 191 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 192 | static int singlethread_cpu __read_mostly; |
Oleg Nesterov | b1f4ec1 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 193 | |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 194 | static struct cpu_workqueue_struct *get_cwq(unsigned int cpu, |
| 195 | struct workqueue_struct *wq) |
Oleg Nesterov | a848e3b | 2007-05-09 02:34:17 -0700 | [diff] [blame] | 196 | { |
Oleg Nesterov | a848e3b | 2007-05-09 02:34:17 -0700 | [diff] [blame] | 197 | return per_cpu_ptr(wq->cpu_wq, cpu); |
| 198 | } |
| 199 | |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 200 | static struct cpu_workqueue_struct *target_cwq(unsigned int cpu, |
| 201 | struct workqueue_struct *wq) |
| 202 | { |
| 203 | if (unlikely(wq->flags & WQ_SINGLE_THREAD)) |
| 204 | cpu = singlethread_cpu; |
| 205 | return get_cwq(cpu, wq); |
| 206 | } |
| 207 | |
David Howells | 4594bf1 | 2006-12-07 11:33:26 +0000 | [diff] [blame] | 208 | /* |
| 209 | * Set the workqueue on which a work item is to be run |
| 210 | * - Must *only* be called if the pending flag is set |
| 211 | */ |
Oleg Nesterov | ed7c0fe | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 212 | static inline void set_wq_data(struct work_struct *work, |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 213 | struct cpu_workqueue_struct *cwq, |
| 214 | unsigned long extra_flags) |
David Howells | 365970a | 2006-11-22 14:54:49 +0000 | [diff] [blame] | 215 | { |
David Howells | 4594bf1 | 2006-12-07 11:33:26 +0000 | [diff] [blame] | 216 | BUG_ON(!work_pending(work)); |
| 217 | |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 218 | atomic_long_set(&work->data, (unsigned long)cwq | work_static(work) | |
Tejun Heo | 22df02b | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 219 | WORK_STRUCT_PENDING | extra_flags); |
David Howells | 365970a | 2006-11-22 14:54:49 +0000 | [diff] [blame] | 220 | } |
| 221 | |
Oleg Nesterov | 4d707b9 | 2010-04-23 17:40:40 +0200 | [diff] [blame] | 222 | /* |
| 223 | * Clear WORK_STRUCT_PENDING and the workqueue on which it was queued. |
| 224 | */ |
| 225 | static inline void clear_wq_data(struct work_struct *work) |
| 226 | { |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 227 | atomic_long_set(&work->data, work_static(work)); |
Oleg Nesterov | 4d707b9 | 2010-04-23 17:40:40 +0200 | [diff] [blame] | 228 | } |
| 229 | |
Tejun Heo | 6416669 | 2010-06-29 10:07:11 +0200 | [diff] [blame] | 230 | static inline struct cpu_workqueue_struct *get_wq_data(struct work_struct *work) |
David Howells | 365970a | 2006-11-22 14:54:49 +0000 | [diff] [blame] | 231 | { |
Tejun Heo | 6416669 | 2010-06-29 10:07:11 +0200 | [diff] [blame] | 232 | return (void *)(atomic_long_read(&work->data) & |
| 233 | WORK_STRUCT_WQ_DATA_MASK); |
David Howells | 365970a | 2006-11-22 14:54:49 +0000 | [diff] [blame] | 234 | } |
| 235 | |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 236 | /** |
| 237 | * insert_work - insert a work into cwq |
| 238 | * @cwq: cwq @work belongs to |
| 239 | * @work: work to insert |
| 240 | * @head: insertion point |
| 241 | * @extra_flags: extra WORK_STRUCT_* flags to set |
| 242 | * |
| 243 | * Insert @work into @cwq after @head. |
| 244 | * |
| 245 | * CONTEXT: |
| 246 | * spin_lock_irq(cwq->lock). |
| 247 | */ |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 248 | static void insert_work(struct cpu_workqueue_struct *cwq, |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 249 | struct work_struct *work, struct list_head *head, |
| 250 | unsigned int extra_flags) |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 251 | { |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 252 | /* we own @work, set data and link */ |
| 253 | set_wq_data(work, cwq, extra_flags); |
| 254 | |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 255 | /* |
| 256 | * Ensure that we get the right work->data if we see the |
| 257 | * result of list_add() below, see try_to_grab_pending(). |
| 258 | */ |
| 259 | smp_wmb(); |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 260 | |
Oleg Nesterov | 1a4d9b0 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 261 | list_add_tail(&work->entry, head); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 262 | wake_up(&cwq->more_work); |
| 263 | } |
| 264 | |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 265 | static void __queue_work(unsigned int cpu, struct workqueue_struct *wq, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | struct work_struct *work) |
| 267 | { |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 268 | struct cpu_workqueue_struct *cwq = target_cwq(cpu, wq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 269 | unsigned long flags; |
| 270 | |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 271 | debug_work_activate(work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | spin_lock_irqsave(&cwq->lock, flags); |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 273 | BUG_ON(!list_empty(&work->entry)); |
| 274 | insert_work(cwq, work, &cwq->worklist, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | spin_unlock_irqrestore(&cwq->lock, flags); |
| 276 | } |
| 277 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 278 | /** |
| 279 | * queue_work - queue work on a workqueue |
| 280 | * @wq: workqueue to use |
| 281 | * @work: work to queue |
| 282 | * |
Alan Stern | 057647f | 2006-10-28 10:38:58 -0700 | [diff] [blame] | 283 | * Returns 0 if @work was already on a queue, non-zero otherwise. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | * |
Oleg Nesterov | 00dfcaf | 2008-04-29 01:00:27 -0700 | [diff] [blame] | 285 | * We queue the work to the CPU on which it was submitted, but if the CPU dies |
| 286 | * it can be processed by another CPU. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 287 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 288 | int queue_work(struct workqueue_struct *wq, struct work_struct *work) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 289 | { |
Oleg Nesterov | ef1ca23 | 2008-07-25 01:47:53 -0700 | [diff] [blame] | 290 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | |
Oleg Nesterov | ef1ca23 | 2008-07-25 01:47:53 -0700 | [diff] [blame] | 292 | ret = queue_work_on(get_cpu(), wq, work); |
| 293 | put_cpu(); |
| 294 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 295 | return ret; |
| 296 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 297 | EXPORT_SYMBOL_GPL(queue_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | |
Zhang Rui | c1a220e | 2008-07-23 21:28:39 -0700 | [diff] [blame] | 299 | /** |
| 300 | * queue_work_on - queue work on specific cpu |
| 301 | * @cpu: CPU number to execute work on |
| 302 | * @wq: workqueue to use |
| 303 | * @work: work to queue |
| 304 | * |
| 305 | * Returns 0 if @work was already on a queue, non-zero otherwise. |
| 306 | * |
| 307 | * We queue the work to a specific CPU, the caller must ensure it |
| 308 | * can't go away. |
| 309 | */ |
| 310 | int |
| 311 | queue_work_on(int cpu, struct workqueue_struct *wq, struct work_struct *work) |
| 312 | { |
| 313 | int ret = 0; |
| 314 | |
Tejun Heo | 22df02b | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 315 | if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) { |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 316 | __queue_work(cpu, wq, work); |
Zhang Rui | c1a220e | 2008-07-23 21:28:39 -0700 | [diff] [blame] | 317 | ret = 1; |
| 318 | } |
| 319 | return ret; |
| 320 | } |
| 321 | EXPORT_SYMBOL_GPL(queue_work_on); |
| 322 | |
Li Zefan | 6d141c3 | 2008-02-08 04:21:09 -0800 | [diff] [blame] | 323 | static void delayed_work_timer_fn(unsigned long __data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 324 | { |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 325 | struct delayed_work *dwork = (struct delayed_work *)__data; |
Oleg Nesterov | ed7c0fe | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 326 | struct cpu_workqueue_struct *cwq = get_wq_data(&dwork->work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 327 | |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 328 | __queue_work(smp_processor_id(), cwq->wq, &dwork->work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | } |
| 330 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 331 | /** |
| 332 | * queue_delayed_work - queue work on a workqueue after delay |
| 333 | * @wq: workqueue to use |
Randy Dunlap | af9997e | 2006-12-22 01:06:52 -0800 | [diff] [blame] | 334 | * @dwork: delayable work to queue |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 335 | * @delay: number of jiffies to wait before queueing |
| 336 | * |
Alan Stern | 057647f | 2006-10-28 10:38:58 -0700 | [diff] [blame] | 337 | * Returns 0 if @work was already on a queue, non-zero otherwise. |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 338 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 339 | int queue_delayed_work(struct workqueue_struct *wq, |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 340 | struct delayed_work *dwork, unsigned long delay) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | { |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 342 | if (delay == 0) |
Oleg Nesterov | 63bc036 | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 343 | return queue_work(wq, &dwork->work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 344 | |
Oleg Nesterov | 63bc036 | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 345 | return queue_delayed_work_on(-1, wq, dwork, delay); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 346 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 347 | EXPORT_SYMBOL_GPL(queue_delayed_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 348 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 349 | /** |
| 350 | * queue_delayed_work_on - queue work on specific CPU after delay |
| 351 | * @cpu: CPU number to execute work on |
| 352 | * @wq: workqueue to use |
Randy Dunlap | af9997e | 2006-12-22 01:06:52 -0800 | [diff] [blame] | 353 | * @dwork: work to queue |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 354 | * @delay: number of jiffies to wait before queueing |
| 355 | * |
Alan Stern | 057647f | 2006-10-28 10:38:58 -0700 | [diff] [blame] | 356 | * Returns 0 if @work was already on a queue, non-zero otherwise. |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 357 | */ |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 358 | int queue_delayed_work_on(int cpu, struct workqueue_struct *wq, |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 359 | struct delayed_work *dwork, unsigned long delay) |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 360 | { |
| 361 | int ret = 0; |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 362 | struct timer_list *timer = &dwork->timer; |
| 363 | struct work_struct *work = &dwork->work; |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 364 | |
Tejun Heo | 22df02b | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 365 | if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) { |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 366 | BUG_ON(timer_pending(timer)); |
| 367 | BUG_ON(!list_empty(&work->entry)); |
| 368 | |
Andrew Liu | 8a3e77c | 2008-05-01 04:35:14 -0700 | [diff] [blame] | 369 | timer_stats_timer_set_start_info(&dwork->timer); |
| 370 | |
Oleg Nesterov | ed7c0fe | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 371 | /* This stores cwq for the moment, for the timer_fn */ |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 372 | set_wq_data(work, target_cwq(raw_smp_processor_id(), wq), 0); |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 373 | timer->expires = jiffies + delay; |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 374 | timer->data = (unsigned long)dwork; |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 375 | timer->function = delayed_work_timer_fn; |
Oleg Nesterov | 63bc036 | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 376 | |
| 377 | if (unlikely(cpu >= 0)) |
| 378 | add_timer_on(timer, cpu); |
| 379 | else |
| 380 | add_timer(timer); |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 381 | ret = 1; |
| 382 | } |
| 383 | return ret; |
| 384 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 385 | EXPORT_SYMBOL_GPL(queue_delayed_work_on); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | |
Tejun Heo | a62428c | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 387 | /** |
| 388 | * process_one_work - process single work |
| 389 | * @cwq: cwq to process work for |
| 390 | * @work: work to process |
| 391 | * |
| 392 | * Process @work. This function contains all the logics necessary to |
| 393 | * process a single work including synchronization against and |
| 394 | * interaction with other workers on the same cpu, queueing and |
| 395 | * flushing. As long as context requirement is met, any worker can |
| 396 | * call this function to process a work. |
| 397 | * |
| 398 | * CONTEXT: |
| 399 | * spin_lock_irq(cwq->lock) which is released and regrabbed. |
| 400 | */ |
| 401 | static void process_one_work(struct cpu_workqueue_struct *cwq, |
| 402 | struct work_struct *work) |
| 403 | { |
| 404 | work_func_t f = work->func; |
| 405 | #ifdef CONFIG_LOCKDEP |
| 406 | /* |
| 407 | * It is permissible to free the struct work_struct from |
| 408 | * inside the function that is called from it, this we need to |
| 409 | * take into account for lockdep too. To avoid bogus "held |
| 410 | * lock freed" warnings as well as problems when looking into |
| 411 | * work->lockdep_map, make a copy and use that here. |
| 412 | */ |
| 413 | struct lockdep_map lockdep_map = work->lockdep_map; |
| 414 | #endif |
| 415 | /* claim and process */ |
Tejun Heo | a62428c | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 416 | debug_work_deactivate(work); |
| 417 | cwq->current_work = work; |
| 418 | list_del_init(&work->entry); |
| 419 | |
| 420 | spin_unlock_irq(&cwq->lock); |
| 421 | |
| 422 | BUG_ON(get_wq_data(work) != cwq); |
| 423 | work_clear_pending(work); |
| 424 | lock_map_acquire(&cwq->wq->lockdep_map); |
| 425 | lock_map_acquire(&lockdep_map); |
| 426 | f(work); |
| 427 | lock_map_release(&lockdep_map); |
| 428 | lock_map_release(&cwq->wq->lockdep_map); |
| 429 | |
| 430 | if (unlikely(in_atomic() || lockdep_depth(current) > 0)) { |
| 431 | printk(KERN_ERR "BUG: workqueue leaked lock or atomic: " |
| 432 | "%s/0x%08x/%d\n", |
| 433 | current->comm, preempt_count(), task_pid_nr(current)); |
| 434 | printk(KERN_ERR " last function: "); |
| 435 | print_symbol("%s\n", (unsigned long)f); |
| 436 | debug_show_held_locks(current); |
| 437 | dump_stack(); |
| 438 | } |
| 439 | |
| 440 | spin_lock_irq(&cwq->lock); |
| 441 | |
| 442 | /* we're done with it, release */ |
| 443 | cwq->current_work = NULL; |
| 444 | } |
| 445 | |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 446 | static void run_workqueue(struct cpu_workqueue_struct *cwq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 447 | { |
Oleg Nesterov | f293ea9 | 2007-05-09 02:34:10 -0700 | [diff] [blame] | 448 | spin_lock_irq(&cwq->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | while (!list_empty(&cwq->worklist)) { |
| 450 | struct work_struct *work = list_entry(cwq->worklist.next, |
| 451 | struct work_struct, entry); |
Tejun Heo | a62428c | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 452 | process_one_work(cwq, work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 453 | } |
Oleg Nesterov | f293ea9 | 2007-05-09 02:34:10 -0700 | [diff] [blame] | 454 | spin_unlock_irq(&cwq->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | } |
| 456 | |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 457 | /** |
| 458 | * worker_thread - the worker thread function |
| 459 | * @__cwq: cwq to serve |
| 460 | * |
| 461 | * The cwq worker thread function. |
| 462 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | static int worker_thread(void *__cwq) |
| 464 | { |
| 465 | struct cpu_workqueue_struct *cwq = __cwq; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 466 | DEFINE_WAIT(wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | |
Tejun Heo | 97e37d7 | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 468 | if (cwq->wq->flags & WQ_FREEZEABLE) |
Rafael J. Wysocki | 8314418 | 2007-07-17 04:03:35 -0700 | [diff] [blame] | 469 | set_freezable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 470 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 471 | for (;;) { |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 472 | prepare_to_wait(&cwq->more_work, &wait, TASK_INTERRUPTIBLE); |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 473 | if (!freezing(current) && |
| 474 | !kthread_should_stop() && |
| 475 | list_empty(&cwq->worklist)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 476 | schedule(); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 477 | finish_wait(&cwq->more_work, &wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | |
Oleg Nesterov | 85f4186 | 2007-05-09 02:34:20 -0700 | [diff] [blame] | 479 | try_to_freeze(); |
| 480 | |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 481 | if (kthread_should_stop()) |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 482 | break; |
| 483 | |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 484 | if (unlikely(!cpumask_equal(&cwq->thread->cpus_allowed, |
| 485 | get_cpu_mask(cwq->cpu)))) |
| 486 | set_cpus_allowed_ptr(cwq->thread, |
| 487 | get_cpu_mask(cwq->cpu)); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 488 | run_workqueue(cwq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 489 | } |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 490 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 491 | return 0; |
| 492 | } |
| 493 | |
Oleg Nesterov | fc2e4d7 | 2007-05-09 02:33:51 -0700 | [diff] [blame] | 494 | struct wq_barrier { |
| 495 | struct work_struct work; |
| 496 | struct completion done; |
| 497 | }; |
| 498 | |
| 499 | static void wq_barrier_func(struct work_struct *work) |
| 500 | { |
| 501 | struct wq_barrier *barr = container_of(work, struct wq_barrier, work); |
| 502 | complete(&barr->done); |
| 503 | } |
| 504 | |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 505 | /** |
| 506 | * insert_wq_barrier - insert a barrier work |
| 507 | * @cwq: cwq to insert barrier into |
| 508 | * @barr: wq_barrier to insert |
| 509 | * @head: insertion point |
| 510 | * |
| 511 | * Insert barrier @barr into @cwq before @head. |
| 512 | * |
| 513 | * CONTEXT: |
| 514 | * spin_lock_irq(cwq->lock). |
| 515 | */ |
Oleg Nesterov | 83c2252 | 2007-05-09 02:33:54 -0700 | [diff] [blame] | 516 | static void insert_wq_barrier(struct cpu_workqueue_struct *cwq, |
Oleg Nesterov | 1a4d9b0 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 517 | struct wq_barrier *barr, struct list_head *head) |
Oleg Nesterov | fc2e4d7 | 2007-05-09 02:33:51 -0700 | [diff] [blame] | 518 | { |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 519 | /* |
| 520 | * debugobject calls are safe here even with cwq->lock locked |
| 521 | * as we know for sure that this will not trigger any of the |
| 522 | * checks and call back into the fixup functions where we |
| 523 | * might deadlock. |
| 524 | */ |
| 525 | INIT_WORK_ON_STACK(&barr->work, wq_barrier_func); |
Tejun Heo | 22df02b | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 526 | __set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(&barr->work)); |
Oleg Nesterov | fc2e4d7 | 2007-05-09 02:33:51 -0700 | [diff] [blame] | 527 | init_completion(&barr->done); |
Oleg Nesterov | 83c2252 | 2007-05-09 02:33:54 -0700 | [diff] [blame] | 528 | |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 529 | debug_work_activate(&barr->work); |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 530 | insert_work(cwq, &barr->work, head, 0); |
Oleg Nesterov | fc2e4d7 | 2007-05-09 02:33:51 -0700 | [diff] [blame] | 531 | } |
| 532 | |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 533 | static int flush_cpu_workqueue(struct cpu_workqueue_struct *cwq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 534 | { |
Lai Jiangshan | 2355b70 | 2009-04-02 16:58:24 -0700 | [diff] [blame] | 535 | int active = 0; |
| 536 | struct wq_barrier barr; |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 537 | |
Lai Jiangshan | 2355b70 | 2009-04-02 16:58:24 -0700 | [diff] [blame] | 538 | WARN_ON(cwq->thread == current); |
| 539 | |
| 540 | spin_lock_irq(&cwq->lock); |
| 541 | if (!list_empty(&cwq->worklist) || cwq->current_work != NULL) { |
| 542 | insert_wq_barrier(cwq, &barr, &cwq->worklist); |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 543 | active = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | } |
Lai Jiangshan | 2355b70 | 2009-04-02 16:58:24 -0700 | [diff] [blame] | 545 | spin_unlock_irq(&cwq->lock); |
| 546 | |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 547 | if (active) { |
Lai Jiangshan | 2355b70 | 2009-04-02 16:58:24 -0700 | [diff] [blame] | 548 | wait_for_completion(&barr.done); |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 549 | destroy_work_on_stack(&barr.work); |
| 550 | } |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 551 | |
| 552 | return active; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 553 | } |
| 554 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 555 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 556 | * flush_workqueue - ensure that any scheduled work has run to completion. |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 557 | * @wq: workqueue to flush |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 558 | * |
| 559 | * Forces execution of the workqueue and blocks until its completion. |
| 560 | * This is typically used in driver shutdown handlers. |
| 561 | * |
Oleg Nesterov | fc2e4d7 | 2007-05-09 02:33:51 -0700 | [diff] [blame] | 562 | * We sleep until all works which were queued on entry have been handled, |
| 563 | * but we are not livelocked by new incoming ones. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 564 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 565 | void flush_workqueue(struct workqueue_struct *wq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 566 | { |
Oleg Nesterov | cce1a16 | 2007-05-09 02:34:13 -0700 | [diff] [blame] | 567 | int cpu; |
Oleg Nesterov | b1f4ec1 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 568 | |
Oleg Nesterov | f293ea9 | 2007-05-09 02:34:10 -0700 | [diff] [blame] | 569 | might_sleep(); |
Ingo Molnar | 3295f0e | 2008-08-11 10:30:30 +0200 | [diff] [blame] | 570 | lock_map_acquire(&wq->lockdep_map); |
| 571 | lock_map_release(&wq->lockdep_map); |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 572 | for_each_possible_cpu(cpu) |
| 573 | flush_cpu_workqueue(get_cwq(cpu, wq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 574 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 575 | EXPORT_SYMBOL_GPL(flush_workqueue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 576 | |
Oleg Nesterov | db70089 | 2008-07-25 01:47:49 -0700 | [diff] [blame] | 577 | /** |
| 578 | * flush_work - block until a work_struct's callback has terminated |
| 579 | * @work: the work which is to be flushed |
| 580 | * |
Oleg Nesterov | a67da70 | 2008-07-25 01:47:52 -0700 | [diff] [blame] | 581 | * Returns false if @work has already terminated. |
| 582 | * |
Oleg Nesterov | db70089 | 2008-07-25 01:47:49 -0700 | [diff] [blame] | 583 | * It is expected that, prior to calling flush_work(), the caller has |
| 584 | * arranged for the work to not be requeued, otherwise it doesn't make |
| 585 | * sense to use this function. |
| 586 | */ |
| 587 | int flush_work(struct work_struct *work) |
| 588 | { |
| 589 | struct cpu_workqueue_struct *cwq; |
| 590 | struct list_head *prev; |
| 591 | struct wq_barrier barr; |
| 592 | |
| 593 | might_sleep(); |
| 594 | cwq = get_wq_data(work); |
| 595 | if (!cwq) |
| 596 | return 0; |
| 597 | |
Ingo Molnar | 3295f0e | 2008-08-11 10:30:30 +0200 | [diff] [blame] | 598 | lock_map_acquire(&cwq->wq->lockdep_map); |
| 599 | lock_map_release(&cwq->wq->lockdep_map); |
Oleg Nesterov | a67da70 | 2008-07-25 01:47:52 -0700 | [diff] [blame] | 600 | |
Oleg Nesterov | db70089 | 2008-07-25 01:47:49 -0700 | [diff] [blame] | 601 | spin_lock_irq(&cwq->lock); |
| 602 | if (!list_empty(&work->entry)) { |
| 603 | /* |
| 604 | * See the comment near try_to_grab_pending()->smp_rmb(). |
| 605 | * If it was re-queued under us we are not going to wait. |
| 606 | */ |
| 607 | smp_rmb(); |
| 608 | if (unlikely(cwq != get_wq_data(work))) |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 609 | goto already_gone; |
Oleg Nesterov | db70089 | 2008-07-25 01:47:49 -0700 | [diff] [blame] | 610 | prev = &work->entry; |
| 611 | } else { |
| 612 | if (cwq->current_work != work) |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 613 | goto already_gone; |
Oleg Nesterov | db70089 | 2008-07-25 01:47:49 -0700 | [diff] [blame] | 614 | prev = &cwq->worklist; |
| 615 | } |
| 616 | insert_wq_barrier(cwq, &barr, prev->next); |
Oleg Nesterov | db70089 | 2008-07-25 01:47:49 -0700 | [diff] [blame] | 617 | |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 618 | spin_unlock_irq(&cwq->lock); |
Oleg Nesterov | db70089 | 2008-07-25 01:47:49 -0700 | [diff] [blame] | 619 | wait_for_completion(&barr.done); |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 620 | destroy_work_on_stack(&barr.work); |
Oleg Nesterov | db70089 | 2008-07-25 01:47:49 -0700 | [diff] [blame] | 621 | return 1; |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 622 | already_gone: |
| 623 | spin_unlock_irq(&cwq->lock); |
| 624 | return 0; |
Oleg Nesterov | db70089 | 2008-07-25 01:47:49 -0700 | [diff] [blame] | 625 | } |
| 626 | EXPORT_SYMBOL_GPL(flush_work); |
| 627 | |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 628 | /* |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 629 | * Upon a successful return (>= 0), the caller "owns" WORK_STRUCT_PENDING bit, |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 630 | * so this work can't be re-armed in any way. |
| 631 | */ |
| 632 | static int try_to_grab_pending(struct work_struct *work) |
| 633 | { |
| 634 | struct cpu_workqueue_struct *cwq; |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 635 | int ret = -1; |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 636 | |
Tejun Heo | 22df02b | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 637 | if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 638 | return 0; |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 639 | |
| 640 | /* |
| 641 | * The queueing is in progress, or it is already queued. Try to |
| 642 | * steal it from ->worklist without clearing WORK_STRUCT_PENDING. |
| 643 | */ |
| 644 | |
| 645 | cwq = get_wq_data(work); |
| 646 | if (!cwq) |
| 647 | return ret; |
| 648 | |
| 649 | spin_lock_irq(&cwq->lock); |
| 650 | if (!list_empty(&work->entry)) { |
| 651 | /* |
| 652 | * This work is queued, but perhaps we locked the wrong cwq. |
| 653 | * In that case we must see the new value after rmb(), see |
| 654 | * insert_work()->wmb(). |
| 655 | */ |
| 656 | smp_rmb(); |
| 657 | if (cwq == get_wq_data(work)) { |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 658 | debug_work_deactivate(work); |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 659 | list_del_init(&work->entry); |
| 660 | ret = 1; |
| 661 | } |
| 662 | } |
| 663 | spin_unlock_irq(&cwq->lock); |
| 664 | |
| 665 | return ret; |
| 666 | } |
| 667 | |
| 668 | static void wait_on_cpu_work(struct cpu_workqueue_struct *cwq, |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 669 | struct work_struct *work) |
| 670 | { |
| 671 | struct wq_barrier barr; |
| 672 | int running = 0; |
| 673 | |
| 674 | spin_lock_irq(&cwq->lock); |
| 675 | if (unlikely(cwq->current_work == work)) { |
Oleg Nesterov | 1a4d9b0 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 676 | insert_wq_barrier(cwq, &barr, cwq->worklist.next); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 677 | running = 1; |
| 678 | } |
| 679 | spin_unlock_irq(&cwq->lock); |
| 680 | |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 681 | if (unlikely(running)) { |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 682 | wait_for_completion(&barr.done); |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 683 | destroy_work_on_stack(&barr.work); |
| 684 | } |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 685 | } |
| 686 | |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 687 | static void wait_on_work(struct work_struct *work) |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 688 | { |
| 689 | struct cpu_workqueue_struct *cwq; |
Oleg Nesterov | 28e53bd | 2007-05-09 02:34:22 -0700 | [diff] [blame] | 690 | struct workqueue_struct *wq; |
Oleg Nesterov | b1f4ec1 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 691 | int cpu; |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 692 | |
Oleg Nesterov | f293ea9 | 2007-05-09 02:34:10 -0700 | [diff] [blame] | 693 | might_sleep(); |
| 694 | |
Ingo Molnar | 3295f0e | 2008-08-11 10:30:30 +0200 | [diff] [blame] | 695 | lock_map_acquire(&work->lockdep_map); |
| 696 | lock_map_release(&work->lockdep_map); |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 697 | |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 698 | cwq = get_wq_data(work); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 699 | if (!cwq) |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 700 | return; |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 701 | |
Oleg Nesterov | 28e53bd | 2007-05-09 02:34:22 -0700 | [diff] [blame] | 702 | wq = cwq->wq; |
Oleg Nesterov | 28e53bd | 2007-05-09 02:34:22 -0700 | [diff] [blame] | 703 | |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 704 | for_each_possible_cpu(cpu) |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 705 | wait_on_cpu_work(get_cwq(cpu, wq), work); |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 706 | } |
| 707 | |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 708 | static int __cancel_work_timer(struct work_struct *work, |
| 709 | struct timer_list* timer) |
| 710 | { |
| 711 | int ret; |
| 712 | |
| 713 | do { |
| 714 | ret = (timer && likely(del_timer(timer))); |
| 715 | if (!ret) |
| 716 | ret = try_to_grab_pending(work); |
| 717 | wait_on_work(work); |
| 718 | } while (unlikely(ret < 0)); |
| 719 | |
Oleg Nesterov | 4d707b9 | 2010-04-23 17:40:40 +0200 | [diff] [blame] | 720 | clear_wq_data(work); |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 721 | return ret; |
| 722 | } |
| 723 | |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 724 | /** |
| 725 | * cancel_work_sync - block until a work_struct's callback has terminated |
| 726 | * @work: the work which is to be flushed |
| 727 | * |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 728 | * Returns true if @work was pending. |
| 729 | * |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 730 | * cancel_work_sync() will cancel the work if it is queued. If the work's |
| 731 | * callback appears to be running, cancel_work_sync() will block until it |
| 732 | * has completed. |
| 733 | * |
| 734 | * It is possible to use this function if the work re-queues itself. It can |
| 735 | * cancel the work even if it migrates to another workqueue, however in that |
| 736 | * case it only guarantees that work->func() has completed on the last queued |
| 737 | * workqueue. |
| 738 | * |
| 739 | * cancel_work_sync(&delayed_work->work) should be used only if ->timer is not |
| 740 | * pending, otherwise it goes into a busy-wait loop until the timer expires. |
| 741 | * |
| 742 | * The caller must ensure that workqueue_struct on which this work was last |
| 743 | * queued can't be destroyed before this function returns. |
| 744 | */ |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 745 | int cancel_work_sync(struct work_struct *work) |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 746 | { |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 747 | return __cancel_work_timer(work, NULL); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 748 | } |
Oleg Nesterov | 28e53bd | 2007-05-09 02:34:22 -0700 | [diff] [blame] | 749 | EXPORT_SYMBOL_GPL(cancel_work_sync); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 750 | |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 751 | /** |
Oleg Nesterov | f5a421a | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 752 | * cancel_delayed_work_sync - reliably kill off a delayed work. |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 753 | * @dwork: the delayed work struct |
| 754 | * |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 755 | * Returns true if @dwork was pending. |
| 756 | * |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 757 | * It is possible to use this function if @dwork rearms itself via queue_work() |
| 758 | * or queue_delayed_work(). See also the comment for cancel_work_sync(). |
| 759 | */ |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 760 | int cancel_delayed_work_sync(struct delayed_work *dwork) |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 761 | { |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 762 | return __cancel_work_timer(&dwork->work, &dwork->timer); |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 763 | } |
Oleg Nesterov | f5a421a | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 764 | EXPORT_SYMBOL(cancel_delayed_work_sync); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 765 | |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 766 | static struct workqueue_struct *keventd_wq __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 767 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 768 | /** |
| 769 | * schedule_work - put work task in global workqueue |
| 770 | * @work: job to be done |
| 771 | * |
Bart Van Assche | 5b0f437d | 2009-07-30 19:00:53 +0200 | [diff] [blame] | 772 | * Returns zero if @work was already on the kernel-global workqueue and |
| 773 | * non-zero otherwise. |
| 774 | * |
| 775 | * This puts a job in the kernel-global workqueue if it was not already |
| 776 | * queued and leaves it in the same position on the kernel-global |
| 777 | * workqueue otherwise. |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 778 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 779 | int schedule_work(struct work_struct *work) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 780 | { |
| 781 | return queue_work(keventd_wq, work); |
| 782 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 783 | EXPORT_SYMBOL(schedule_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 784 | |
Zhang Rui | c1a220e | 2008-07-23 21:28:39 -0700 | [diff] [blame] | 785 | /* |
| 786 | * schedule_work_on - put work task on a specific cpu |
| 787 | * @cpu: cpu to put the work task on |
| 788 | * @work: job to be done |
| 789 | * |
| 790 | * This puts a job on a specific cpu |
| 791 | */ |
| 792 | int schedule_work_on(int cpu, struct work_struct *work) |
| 793 | { |
| 794 | return queue_work_on(cpu, keventd_wq, work); |
| 795 | } |
| 796 | EXPORT_SYMBOL(schedule_work_on); |
| 797 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 798 | /** |
| 799 | * schedule_delayed_work - put work task in global workqueue after delay |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 800 | * @dwork: job to be done |
| 801 | * @delay: number of jiffies to wait or 0 for immediate execution |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 802 | * |
| 803 | * After waiting for a given time this puts a job in the kernel-global |
| 804 | * workqueue. |
| 805 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 806 | int schedule_delayed_work(struct delayed_work *dwork, |
Ingo Molnar | 82f67cd | 2007-02-16 01:28:13 -0800 | [diff] [blame] | 807 | unsigned long delay) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | { |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 809 | return queue_delayed_work(keventd_wq, dwork, delay); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 810 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 811 | EXPORT_SYMBOL(schedule_delayed_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 812 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 813 | /** |
Linus Torvalds | 8c53e46 | 2009-10-14 09:16:42 -0700 | [diff] [blame] | 814 | * flush_delayed_work - block until a dwork_struct's callback has terminated |
| 815 | * @dwork: the delayed work which is to be flushed |
| 816 | * |
| 817 | * Any timeout is cancelled, and any pending work is run immediately. |
| 818 | */ |
| 819 | void flush_delayed_work(struct delayed_work *dwork) |
| 820 | { |
| 821 | if (del_timer_sync(&dwork->timer)) { |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 822 | __queue_work(get_cpu(), get_wq_data(&dwork->work)->wq, |
| 823 | &dwork->work); |
Linus Torvalds | 8c53e46 | 2009-10-14 09:16:42 -0700 | [diff] [blame] | 824 | put_cpu(); |
| 825 | } |
| 826 | flush_work(&dwork->work); |
| 827 | } |
| 828 | EXPORT_SYMBOL(flush_delayed_work); |
| 829 | |
| 830 | /** |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 831 | * schedule_delayed_work_on - queue work in global workqueue on CPU after delay |
| 832 | * @cpu: cpu to use |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 833 | * @dwork: job to be done |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 834 | * @delay: number of jiffies to wait |
| 835 | * |
| 836 | * After waiting for a given time this puts a job in the kernel-global |
| 837 | * workqueue on the specified CPU. |
| 838 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 839 | int schedule_delayed_work_on(int cpu, |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 840 | struct delayed_work *dwork, unsigned long delay) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 841 | { |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 842 | return queue_delayed_work_on(cpu, keventd_wq, dwork, delay); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 843 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 844 | EXPORT_SYMBOL(schedule_delayed_work_on); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 845 | |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 846 | /** |
| 847 | * schedule_on_each_cpu - call a function on each online CPU from keventd |
| 848 | * @func: the function to call |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 849 | * |
| 850 | * Returns zero on success. |
| 851 | * Returns -ve errno on failure. |
| 852 | * |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 853 | * schedule_on_each_cpu() is very slow. |
| 854 | */ |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 855 | int schedule_on_each_cpu(work_func_t func) |
Christoph Lameter | 15316ba | 2006-01-08 01:00:43 -0800 | [diff] [blame] | 856 | { |
| 857 | int cpu; |
Andi Kleen | 65a6446 | 2009-10-14 06:22:47 +0200 | [diff] [blame] | 858 | int orig = -1; |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 859 | struct work_struct *works; |
Christoph Lameter | 15316ba | 2006-01-08 01:00:43 -0800 | [diff] [blame] | 860 | |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 861 | works = alloc_percpu(struct work_struct); |
| 862 | if (!works) |
Christoph Lameter | 15316ba | 2006-01-08 01:00:43 -0800 | [diff] [blame] | 863 | return -ENOMEM; |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 864 | |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 865 | get_online_cpus(); |
Tejun Heo | 9398180 | 2009-11-17 14:06:20 -0800 | [diff] [blame] | 866 | |
| 867 | /* |
| 868 | * When running in keventd don't schedule a work item on |
| 869 | * itself. Can just call directly because the work queue is |
| 870 | * already bound. This also is faster. |
| 871 | */ |
| 872 | if (current_is_keventd()) |
| 873 | orig = raw_smp_processor_id(); |
| 874 | |
Christoph Lameter | 15316ba | 2006-01-08 01:00:43 -0800 | [diff] [blame] | 875 | for_each_online_cpu(cpu) { |
Ingo Molnar | 9bfb183 | 2006-12-18 20:05:09 +0100 | [diff] [blame] | 876 | struct work_struct *work = per_cpu_ptr(works, cpu); |
| 877 | |
| 878 | INIT_WORK(work, func); |
Andi Kleen | 65a6446 | 2009-10-14 06:22:47 +0200 | [diff] [blame] | 879 | if (cpu != orig) |
Tejun Heo | 9398180 | 2009-11-17 14:06:20 -0800 | [diff] [blame] | 880 | schedule_work_on(cpu, work); |
Andi Kleen | 65a6446 | 2009-10-14 06:22:47 +0200 | [diff] [blame] | 881 | } |
Tejun Heo | 9398180 | 2009-11-17 14:06:20 -0800 | [diff] [blame] | 882 | if (orig >= 0) |
| 883 | func(per_cpu_ptr(works, orig)); |
| 884 | |
| 885 | for_each_online_cpu(cpu) |
| 886 | flush_work(per_cpu_ptr(works, cpu)); |
| 887 | |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 888 | put_online_cpus(); |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 889 | free_percpu(works); |
Christoph Lameter | 15316ba | 2006-01-08 01:00:43 -0800 | [diff] [blame] | 890 | return 0; |
| 891 | } |
| 892 | |
Alan Stern | eef6a7d | 2010-02-12 17:39:21 +0900 | [diff] [blame] | 893 | /** |
| 894 | * flush_scheduled_work - ensure that any scheduled work has run to completion. |
| 895 | * |
| 896 | * Forces execution of the kernel-global workqueue and blocks until its |
| 897 | * completion. |
| 898 | * |
| 899 | * Think twice before calling this function! It's very easy to get into |
| 900 | * trouble if you don't take great care. Either of the following situations |
| 901 | * will lead to deadlock: |
| 902 | * |
| 903 | * One of the work items currently on the workqueue needs to acquire |
| 904 | * a lock held by your code or its caller. |
| 905 | * |
| 906 | * Your code is running in the context of a work routine. |
| 907 | * |
| 908 | * They will be detected by lockdep when they occur, but the first might not |
| 909 | * occur very often. It depends on what work items are on the workqueue and |
| 910 | * what locks they need, which you have no control over. |
| 911 | * |
| 912 | * In most situations flushing the entire workqueue is overkill; you merely |
| 913 | * need to know that a particular work item isn't queued and isn't running. |
| 914 | * In such cases you should use cancel_delayed_work_sync() or |
| 915 | * cancel_work_sync() instead. |
| 916 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 917 | void flush_scheduled_work(void) |
| 918 | { |
| 919 | flush_workqueue(keventd_wq); |
| 920 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 921 | EXPORT_SYMBOL(flush_scheduled_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 922 | |
| 923 | /** |
James Bottomley | 1fa44ec | 2006-02-23 12:43:43 -0600 | [diff] [blame] | 924 | * execute_in_process_context - reliably execute the routine with user context |
| 925 | * @fn: the function to execute |
James Bottomley | 1fa44ec | 2006-02-23 12:43:43 -0600 | [diff] [blame] | 926 | * @ew: guaranteed storage for the execute work structure (must |
| 927 | * be available when the work executes) |
| 928 | * |
| 929 | * Executes the function immediately if process context is available, |
| 930 | * otherwise schedules the function for delayed execution. |
| 931 | * |
| 932 | * Returns: 0 - function was executed |
| 933 | * 1 - function was scheduled for execution |
| 934 | */ |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 935 | int execute_in_process_context(work_func_t fn, struct execute_work *ew) |
James Bottomley | 1fa44ec | 2006-02-23 12:43:43 -0600 | [diff] [blame] | 936 | { |
| 937 | if (!in_interrupt()) { |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 938 | fn(&ew->work); |
James Bottomley | 1fa44ec | 2006-02-23 12:43:43 -0600 | [diff] [blame] | 939 | return 0; |
| 940 | } |
| 941 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 942 | INIT_WORK(&ew->work, fn); |
James Bottomley | 1fa44ec | 2006-02-23 12:43:43 -0600 | [diff] [blame] | 943 | schedule_work(&ew->work); |
| 944 | |
| 945 | return 1; |
| 946 | } |
| 947 | EXPORT_SYMBOL_GPL(execute_in_process_context); |
| 948 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 949 | int keventd_up(void) |
| 950 | { |
| 951 | return keventd_wq != NULL; |
| 952 | } |
| 953 | |
| 954 | int current_is_keventd(void) |
| 955 | { |
| 956 | struct cpu_workqueue_struct *cwq; |
Hugh Dickins | d243769 | 2007-08-27 16:06:19 +0100 | [diff] [blame] | 957 | int cpu = raw_smp_processor_id(); /* preempt-safe: keventd is per-cpu */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 958 | int ret = 0; |
| 959 | |
| 960 | BUG_ON(!keventd_wq); |
| 961 | |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 962 | cwq = get_cwq(cpu, keventd_wq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 963 | if (current == cwq->thread) |
| 964 | ret = 1; |
| 965 | |
| 966 | return ret; |
| 967 | |
| 968 | } |
| 969 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 970 | static int create_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 971 | { |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 972 | struct workqueue_struct *wq = cwq->wq; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 973 | struct task_struct *p; |
| 974 | |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 975 | p = kthread_create(worker_thread, cwq, "%s/%d", wq->name, cpu); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 976 | /* |
| 977 | * Nobody can add the work_struct to this cwq, |
| 978 | * if (caller is __create_workqueue) |
| 979 | * nobody should see this wq |
| 980 | * else // caller is CPU_UP_PREPARE |
| 981 | * cpu is not on cpu_online_map |
| 982 | * so we can abort safely. |
| 983 | */ |
| 984 | if (IS_ERR(p)) |
| 985 | return PTR_ERR(p); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 986 | cwq->thread = p; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 987 | |
| 988 | return 0; |
| 989 | } |
| 990 | |
Oleg Nesterov | 06ba38a | 2007-05-09 02:34:15 -0700 | [diff] [blame] | 991 | static void start_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu) |
| 992 | { |
| 993 | struct task_struct *p = cwq->thread; |
| 994 | |
| 995 | if (p != NULL) { |
| 996 | if (cpu >= 0) |
| 997 | kthread_bind(p, cpu); |
| 998 | wake_up_process(p); |
| 999 | } |
| 1000 | } |
| 1001 | |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 1002 | struct workqueue_struct *__create_workqueue_key(const char *name, |
Tejun Heo | 97e37d7 | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 1003 | unsigned int flags, |
Johannes Berg | eb13ba8 | 2008-01-16 09:51:58 +0100 | [diff] [blame] | 1004 | struct lock_class_key *key, |
| 1005 | const char *lock_name) |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1006 | { |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 1007 | bool singlethread = flags & WQ_SINGLE_THREAD; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1008 | struct workqueue_struct *wq; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1009 | int err = 0, cpu; |
| 1010 | |
| 1011 | wq = kzalloc(sizeof(*wq), GFP_KERNEL); |
| 1012 | if (!wq) |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 1013 | goto err; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1014 | |
| 1015 | wq->cpu_wq = alloc_percpu(struct cpu_workqueue_struct); |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 1016 | if (!wq->cpu_wq) |
| 1017 | goto err; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1018 | |
Tejun Heo | 97e37d7 | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 1019 | wq->flags = flags; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1020 | wq->name = name; |
Johannes Berg | eb13ba8 | 2008-01-16 09:51:58 +0100 | [diff] [blame] | 1021 | lockdep_init_map(&wq->lockdep_map, lock_name, key, 0); |
Oleg Nesterov | cce1a16 | 2007-05-09 02:34:13 -0700 | [diff] [blame] | 1022 | INIT_LIST_HEAD(&wq->list); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1023 | |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 1024 | cpu_maps_update_begin(); |
| 1025 | /* |
| 1026 | * We must initialize cwqs for each possible cpu even if we |
| 1027 | * are going to call destroy_workqueue() finally. Otherwise |
| 1028 | * cpu_up() can hit the uninitialized cwq once we drop the |
| 1029 | * lock. |
| 1030 | */ |
| 1031 | for_each_possible_cpu(cpu) { |
| 1032 | struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq); |
| 1033 | |
| 1034 | cwq->wq = wq; |
| 1035 | cwq->cpu = cpu; |
| 1036 | spin_lock_init(&cwq->lock); |
| 1037 | INIT_LIST_HEAD(&cwq->worklist); |
| 1038 | init_waitqueue_head(&cwq->more_work); |
| 1039 | |
| 1040 | if (err) |
| 1041 | continue; |
| 1042 | err = create_workqueue_thread(cwq, cpu); |
| 1043 | if (cpu_online(cpu) && !singlethread) |
Oleg Nesterov | 06ba38a | 2007-05-09 02:34:15 -0700 | [diff] [blame] | 1044 | start_workqueue_thread(cwq, cpu); |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 1045 | else |
| 1046 | start_workqueue_thread(cwq, -1); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1047 | } |
| 1048 | |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 1049 | spin_lock(&workqueue_lock); |
| 1050 | list_add(&wq->list, &workqueues); |
| 1051 | spin_unlock(&workqueue_lock); |
| 1052 | |
| 1053 | cpu_maps_update_done(); |
| 1054 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1055 | if (err) { |
| 1056 | destroy_workqueue(wq); |
| 1057 | wq = NULL; |
| 1058 | } |
| 1059 | return wq; |
Tejun Heo | 4690c4a | 2010-06-29 10:07:10 +0200 | [diff] [blame] | 1060 | err: |
| 1061 | if (wq) { |
| 1062 | free_percpu(wq->cpu_wq); |
| 1063 | kfree(wq); |
| 1064 | } |
| 1065 | return NULL; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1066 | } |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 1067 | EXPORT_SYMBOL_GPL(__create_workqueue_key); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1068 | |
Oleg Nesterov | 1e35eaa | 2008-04-29 01:00:28 -0700 | [diff] [blame] | 1069 | static void cleanup_workqueue_thread(struct cpu_workqueue_struct *cwq) |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1070 | { |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 1071 | /* |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 1072 | * Our caller is either destroy_workqueue() or CPU_POST_DEAD, |
| 1073 | * cpu_add_remove_lock protects cwq->thread. |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 1074 | */ |
| 1075 | if (cwq->thread == NULL) |
| 1076 | return; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1077 | |
Ingo Molnar | 3295f0e | 2008-08-11 10:30:30 +0200 | [diff] [blame] | 1078 | lock_map_acquire(&cwq->wq->lockdep_map); |
| 1079 | lock_map_release(&cwq->wq->lockdep_map); |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 1080 | |
Oleg Nesterov | 13c2216 | 2007-07-17 04:03:55 -0700 | [diff] [blame] | 1081 | flush_cpu_workqueue(cwq); |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 1082 | /* |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 1083 | * If the caller is CPU_POST_DEAD and cwq->worklist was not empty, |
Oleg Nesterov | 13c2216 | 2007-07-17 04:03:55 -0700 | [diff] [blame] | 1084 | * a concurrent flush_workqueue() can insert a barrier after us. |
| 1085 | * However, in that case run_workqueue() won't return and check |
| 1086 | * kthread_should_stop() until it flushes all work_struct's. |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 1087 | * When ->worklist becomes empty it is safe to exit because no |
| 1088 | * more work_structs can be queued on this cwq: flush_workqueue |
| 1089 | * checks list_empty(), and a "normal" queue_work() can't use |
| 1090 | * a dead CPU. |
| 1091 | */ |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 1092 | kthread_stop(cwq->thread); |
| 1093 | cwq->thread = NULL; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1094 | } |
| 1095 | |
| 1096 | /** |
| 1097 | * destroy_workqueue - safely terminate a workqueue |
| 1098 | * @wq: target workqueue |
| 1099 | * |
| 1100 | * Safely destroy a workqueue. All work currently pending will be done first. |
| 1101 | */ |
| 1102 | void destroy_workqueue(struct workqueue_struct *wq) |
| 1103 | { |
Oleg Nesterov | b1f4ec1 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 1104 | int cpu; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1105 | |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 1106 | cpu_maps_update_begin(); |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 1107 | spin_lock(&workqueue_lock); |
Oleg Nesterov | b1f4ec1 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 1108 | list_del(&wq->list); |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 1109 | spin_unlock(&workqueue_lock); |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 1110 | cpu_maps_update_done(); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1111 | |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 1112 | for_each_possible_cpu(cpu) |
| 1113 | cleanup_workqueue_thread(get_cwq(cpu, wq)); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1114 | |
| 1115 | free_percpu(wq->cpu_wq); |
| 1116 | kfree(wq); |
| 1117 | } |
| 1118 | EXPORT_SYMBOL_GPL(destroy_workqueue); |
| 1119 | |
| 1120 | static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, |
| 1121 | unsigned long action, |
| 1122 | void *hcpu) |
| 1123 | { |
| 1124 | unsigned int cpu = (unsigned long)hcpu; |
| 1125 | struct cpu_workqueue_struct *cwq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1126 | struct workqueue_struct *wq; |
| 1127 | |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 1128 | action &= ~CPU_TASKS_FROZEN; |
| 1129 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1130 | list_for_each_entry(wq, &workqueues, list) { |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 1131 | if (wq->flags & WQ_SINGLE_THREAD) |
| 1132 | continue; |
| 1133 | |
| 1134 | cwq = get_cwq(cpu, wq); |
Christoph Lameter | 89ada67 | 2005-10-30 15:01:59 -0800 | [diff] [blame] | 1135 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1136 | switch (action) { |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 1137 | case CPU_POST_DEAD: |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 1138 | lock_map_acquire(&cwq->wq->lockdep_map); |
| 1139 | lock_map_release(&cwq->wq->lockdep_map); |
| 1140 | flush_cpu_workqueue(cwq); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1141 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1142 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1143 | } |
| 1144 | |
Tejun Heo | 1537663 | 2010-06-29 10:07:11 +0200 | [diff] [blame^] | 1145 | return notifier_from_errno(0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1146 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1147 | |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1148 | #ifdef CONFIG_SMP |
Rusty Russell | 8ccad40 | 2009-01-16 15:31:15 -0800 | [diff] [blame] | 1149 | |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1150 | struct work_for_cpu { |
Andrew Morton | 6b44003e | 2009-04-09 09:50:37 -0600 | [diff] [blame] | 1151 | struct completion completion; |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1152 | long (*fn)(void *); |
| 1153 | void *arg; |
| 1154 | long ret; |
| 1155 | }; |
| 1156 | |
Andrew Morton | 6b44003e | 2009-04-09 09:50:37 -0600 | [diff] [blame] | 1157 | static int do_work_for_cpu(void *_wfc) |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1158 | { |
Andrew Morton | 6b44003e | 2009-04-09 09:50:37 -0600 | [diff] [blame] | 1159 | struct work_for_cpu *wfc = _wfc; |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1160 | wfc->ret = wfc->fn(wfc->arg); |
Andrew Morton | 6b44003e | 2009-04-09 09:50:37 -0600 | [diff] [blame] | 1161 | complete(&wfc->completion); |
| 1162 | return 0; |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1163 | } |
| 1164 | |
| 1165 | /** |
| 1166 | * work_on_cpu - run a function in user context on a particular cpu |
| 1167 | * @cpu: the cpu to run on |
| 1168 | * @fn: the function to run |
| 1169 | * @arg: the function arg |
| 1170 | * |
Rusty Russell | 31ad908 | 2009-01-16 15:31:15 -0800 | [diff] [blame] | 1171 | * This will return the value @fn returns. |
| 1172 | * It is up to the caller to ensure that the cpu doesn't go offline. |
Andrew Morton | 6b44003e | 2009-04-09 09:50:37 -0600 | [diff] [blame] | 1173 | * The caller must not hold any locks which would prevent @fn from completing. |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1174 | */ |
| 1175 | long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg) |
| 1176 | { |
Andrew Morton | 6b44003e | 2009-04-09 09:50:37 -0600 | [diff] [blame] | 1177 | struct task_struct *sub_thread; |
| 1178 | struct work_for_cpu wfc = { |
| 1179 | .completion = COMPLETION_INITIALIZER_ONSTACK(wfc.completion), |
| 1180 | .fn = fn, |
| 1181 | .arg = arg, |
| 1182 | }; |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1183 | |
Andrew Morton | 6b44003e | 2009-04-09 09:50:37 -0600 | [diff] [blame] | 1184 | sub_thread = kthread_create(do_work_for_cpu, &wfc, "work_for_cpu"); |
| 1185 | if (IS_ERR(sub_thread)) |
| 1186 | return PTR_ERR(sub_thread); |
| 1187 | kthread_bind(sub_thread, cpu); |
| 1188 | wake_up_process(sub_thread); |
| 1189 | wait_for_completion(&wfc.completion); |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1190 | return wfc.ret; |
| 1191 | } |
| 1192 | EXPORT_SYMBOL_GPL(work_on_cpu); |
| 1193 | #endif /* CONFIG_SMP */ |
| 1194 | |
Oleg Nesterov | c12920d | 2007-05-09 02:34:14 -0700 | [diff] [blame] | 1195 | void __init init_workqueues(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1196 | { |
Rusty Russell | e7577c5 | 2009-01-01 10:12:25 +1030 | [diff] [blame] | 1197 | singlethread_cpu = cpumask_first(cpu_possible_mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1198 | hotcpu_notifier(workqueue_cpu_callback, 0); |
| 1199 | keventd_wq = create_workqueue("events"); |
| 1200 | BUG_ON(!keventd_wq); |
| 1201 | } |