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 | 46934023 | 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> |
Zhaolei | fb39125f | 2009-04-17 15:15:51 +0800 | [diff] [blame] | 36 | #define CREATE_TRACE_POINTS |
| 37 | #include <trace/events/workqueue.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | |
| 39 | /* |
Nathan Lynch | f756d5e | 2006-01-08 01:05:12 -0800 | [diff] [blame] | 40 | * The per-CPU workqueue (if single thread, we always use the first |
| 41 | * possible cpu). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | */ |
| 43 | struct cpu_workqueue_struct { |
| 44 | |
| 45 | spinlock_t lock; |
| 46 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | struct list_head worklist; |
| 48 | wait_queue_head_t more_work; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 49 | struct work_struct *current_work; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | |
| 51 | struct workqueue_struct *wq; |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 52 | struct task_struct *thread; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | } ____cacheline_aligned; |
| 54 | |
| 55 | /* |
| 56 | * The externally visible workqueue abstraction is an array of |
| 57 | * per-CPU workqueues: |
| 58 | */ |
| 59 | struct workqueue_struct { |
Christoph Lameter | 89ada67 | 2005-10-30 15:01:59 -0800 | [diff] [blame] | 60 | struct cpu_workqueue_struct *cpu_wq; |
Oleg Nesterov | cce1a16 | 2007-05-09 02:34:13 -0700 | [diff] [blame] | 61 | struct list_head list; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | const char *name; |
Oleg Nesterov | cce1a16 | 2007-05-09 02:34:13 -0700 | [diff] [blame] | 63 | int singlethread; |
Oleg Nesterov | 319c2a9 | 2007-05-09 02:34:06 -0700 | [diff] [blame] | 64 | int freezeable; /* Freeze threads during suspend */ |
Heiko Carstens | 0d557dc | 2008-10-13 23:50:09 +0200 | [diff] [blame] | 65 | int rt; |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 66 | #ifdef CONFIG_LOCKDEP |
| 67 | struct lockdep_map lockdep_map; |
| 68 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | }; |
| 70 | |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 71 | #ifdef CONFIG_DEBUG_OBJECTS_WORK |
| 72 | |
| 73 | static struct debug_obj_descr work_debug_descr; |
| 74 | |
| 75 | /* |
| 76 | * fixup_init is called when: |
| 77 | * - an active object is initialized |
| 78 | */ |
| 79 | static int work_fixup_init(void *addr, enum debug_obj_state state) |
| 80 | { |
| 81 | struct work_struct *work = addr; |
| 82 | |
| 83 | switch (state) { |
| 84 | case ODEBUG_STATE_ACTIVE: |
| 85 | cancel_work_sync(work); |
| 86 | debug_object_init(work, &work_debug_descr); |
| 87 | return 1; |
| 88 | default: |
| 89 | return 0; |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | /* |
| 94 | * fixup_activate is called when: |
| 95 | * - an active object is activated |
| 96 | * - an unknown object is activated (might be a statically initialized object) |
| 97 | */ |
| 98 | static int work_fixup_activate(void *addr, enum debug_obj_state state) |
| 99 | { |
| 100 | struct work_struct *work = addr; |
| 101 | |
| 102 | switch (state) { |
| 103 | |
| 104 | case ODEBUG_STATE_NOTAVAILABLE: |
| 105 | /* |
| 106 | * This is not really a fixup. The work struct was |
| 107 | * statically initialized. We just make sure that it |
| 108 | * is tracked in the object tracker. |
| 109 | */ |
| 110 | if (test_bit(WORK_STRUCT_STATIC, work_data_bits(work))) { |
| 111 | debug_object_init(work, &work_debug_descr); |
| 112 | debug_object_activate(work, &work_debug_descr); |
| 113 | return 0; |
| 114 | } |
| 115 | WARN_ON_ONCE(1); |
| 116 | return 0; |
| 117 | |
| 118 | case ODEBUG_STATE_ACTIVE: |
| 119 | WARN_ON(1); |
| 120 | |
| 121 | default: |
| 122 | return 0; |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | /* |
| 127 | * fixup_free is called when: |
| 128 | * - an active object is freed |
| 129 | */ |
| 130 | static int work_fixup_free(void *addr, enum debug_obj_state state) |
| 131 | { |
| 132 | struct work_struct *work = addr; |
| 133 | |
| 134 | switch (state) { |
| 135 | case ODEBUG_STATE_ACTIVE: |
| 136 | cancel_work_sync(work); |
| 137 | debug_object_free(work, &work_debug_descr); |
| 138 | return 1; |
| 139 | default: |
| 140 | return 0; |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | static struct debug_obj_descr work_debug_descr = { |
| 145 | .name = "work_struct", |
| 146 | .fixup_init = work_fixup_init, |
| 147 | .fixup_activate = work_fixup_activate, |
| 148 | .fixup_free = work_fixup_free, |
| 149 | }; |
| 150 | |
| 151 | static inline void debug_work_activate(struct work_struct *work) |
| 152 | { |
| 153 | debug_object_activate(work, &work_debug_descr); |
| 154 | } |
| 155 | |
| 156 | static inline void debug_work_deactivate(struct work_struct *work) |
| 157 | { |
| 158 | debug_object_deactivate(work, &work_debug_descr); |
| 159 | } |
| 160 | |
| 161 | void __init_work(struct work_struct *work, int onstack) |
| 162 | { |
| 163 | if (onstack) |
| 164 | debug_object_init_on_stack(work, &work_debug_descr); |
| 165 | else |
| 166 | debug_object_init(work, &work_debug_descr); |
| 167 | } |
| 168 | EXPORT_SYMBOL_GPL(__init_work); |
| 169 | |
| 170 | void destroy_work_on_stack(struct work_struct *work) |
| 171 | { |
| 172 | debug_object_free(work, &work_debug_descr); |
| 173 | } |
| 174 | EXPORT_SYMBOL_GPL(destroy_work_on_stack); |
| 175 | |
| 176 | #else |
| 177 | static inline void debug_work_activate(struct work_struct *work) { } |
| 178 | static inline void debug_work_deactivate(struct work_struct *work) { } |
| 179 | #endif |
| 180 | |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 181 | /* Serializes the accesses to the list of workqueues. */ |
| 182 | static DEFINE_SPINLOCK(workqueue_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | static LIST_HEAD(workqueues); |
| 184 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 185 | static int singlethread_cpu __read_mostly; |
Rusty Russell | e7577c5 | 2009-01-01 10:12:25 +1030 | [diff] [blame] | 186 | static const struct cpumask *cpu_singlethread_map __read_mostly; |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 187 | /* |
| 188 | * _cpu_down() first removes CPU from cpu_online_map, then CPU_DEAD |
| 189 | * flushes cwq->worklist. This means that flush_workqueue/wait_on_work |
| 190 | * which comes in between can't use for_each_online_cpu(). We could |
| 191 | * use cpu_possible_map, the cpumask below is more a documentation |
| 192 | * than optimization. |
| 193 | */ |
Rusty Russell | e7577c5 | 2009-01-01 10:12:25 +1030 | [diff] [blame] | 194 | static cpumask_var_t cpu_populated_map __read_mostly; |
Nathan Lynch | f756d5e | 2006-01-08 01:05:12 -0800 | [diff] [blame] | 195 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 196 | /* If it's single threaded, it isn't in the list of workqueues. */ |
David Howells | 6cc88bc | 2008-11-14 10:39:21 +1100 | [diff] [blame] | 197 | static inline int is_wq_single_threaded(struct workqueue_struct *wq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | { |
Oleg Nesterov | cce1a16 | 2007-05-09 02:34:13 -0700 | [diff] [blame] | 199 | return wq->singlethread; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | } |
| 201 | |
Rusty Russell | e7577c5 | 2009-01-01 10:12:25 +1030 | [diff] [blame] | 202 | static const struct cpumask *wq_cpu_map(struct workqueue_struct *wq) |
Oleg Nesterov | b1f4ec17 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 203 | { |
David Howells | 6cc88bc | 2008-11-14 10:39:21 +1100 | [diff] [blame] | 204 | return is_wq_single_threaded(wq) |
Rusty Russell | e7577c5 | 2009-01-01 10:12:25 +1030 | [diff] [blame] | 205 | ? cpu_singlethread_map : cpu_populated_map; |
Oleg Nesterov | b1f4ec17 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 206 | } |
| 207 | |
Oleg Nesterov | a848e3b | 2007-05-09 02:34:17 -0700 | [diff] [blame] | 208 | static |
| 209 | struct cpu_workqueue_struct *wq_per_cpu(struct workqueue_struct *wq, int cpu) |
| 210 | { |
David Howells | 6cc88bc | 2008-11-14 10:39:21 +1100 | [diff] [blame] | 211 | if (unlikely(is_wq_single_threaded(wq))) |
Oleg Nesterov | a848e3b | 2007-05-09 02:34:17 -0700 | [diff] [blame] | 212 | cpu = singlethread_cpu; |
| 213 | return per_cpu_ptr(wq->cpu_wq, cpu); |
| 214 | } |
| 215 | |
David Howells | 4594bf1 | 2006-12-07 11:33:26 +0000 | [diff] [blame] | 216 | /* |
| 217 | * Set the workqueue on which a work item is to be run |
| 218 | * - Must *only* be called if the pending flag is set |
| 219 | */ |
Oleg Nesterov | ed7c0fe | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 220 | static inline void set_wq_data(struct work_struct *work, |
| 221 | struct cpu_workqueue_struct *cwq) |
David Howells | 365970a | 2006-11-22 14:54:49 +0000 | [diff] [blame] | 222 | { |
David Howells | 4594bf1 | 2006-12-07 11:33:26 +0000 | [diff] [blame] | 223 | unsigned long new; |
David Howells | 365970a | 2006-11-22 14:54:49 +0000 | [diff] [blame] | 224 | |
David Howells | 4594bf1 | 2006-12-07 11:33:26 +0000 | [diff] [blame] | 225 | BUG_ON(!work_pending(work)); |
| 226 | |
Oleg Nesterov | ed7c0fe | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 227 | new = (unsigned long) cwq | (1UL << WORK_STRUCT_PENDING); |
Linus Torvalds | a08727b | 2006-12-16 09:53:50 -0800 | [diff] [blame] | 228 | new |= WORK_STRUCT_FLAG_MASK & *work_data_bits(work); |
| 229 | atomic_long_set(&work->data, new); |
David Howells | 365970a | 2006-11-22 14:54:49 +0000 | [diff] [blame] | 230 | } |
| 231 | |
Oleg Nesterov | 4d707b9 | 2010-04-23 17:40:40 +0200 | [diff] [blame] | 232 | /* |
| 233 | * Clear WORK_STRUCT_PENDING and the workqueue on which it was queued. |
| 234 | */ |
| 235 | static inline void clear_wq_data(struct work_struct *work) |
| 236 | { |
| 237 | unsigned long flags = *work_data_bits(work) & |
| 238 | (1UL << WORK_STRUCT_STATIC); |
| 239 | atomic_long_set(&work->data, flags); |
| 240 | } |
| 241 | |
Oleg Nesterov | ed7c0fe | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 242 | static inline |
| 243 | struct cpu_workqueue_struct *get_wq_data(struct work_struct *work) |
David Howells | 365970a | 2006-11-22 14:54:49 +0000 | [diff] [blame] | 244 | { |
Linus Torvalds | a08727b | 2006-12-16 09:53:50 -0800 | [diff] [blame] | 245 | return (void *) (atomic_long_read(&work->data) & WORK_STRUCT_WQ_DATA_MASK); |
David Howells | 365970a | 2006-11-22 14:54:49 +0000 | [diff] [blame] | 246 | } |
| 247 | |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 248 | static void insert_work(struct cpu_workqueue_struct *cwq, |
Oleg Nesterov | 1a4d9b0 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 249 | struct work_struct *work, struct list_head *head) |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 250 | { |
Frederic Weisbecker | e1d8aa9 | 2009-01-12 23:15:46 +0100 | [diff] [blame] | 251 | trace_workqueue_insertion(cwq->thread, work); |
| 252 | |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 253 | set_wq_data(work, cwq); |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 254 | /* |
| 255 | * Ensure that we get the right work->data if we see the |
| 256 | * result of list_add() below, see try_to_grab_pending(). |
| 257 | */ |
| 258 | smp_wmb(); |
Oleg Nesterov | 1a4d9b0 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 259 | list_add_tail(&work->entry, head); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 260 | wake_up(&cwq->more_work); |
| 261 | } |
| 262 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 263 | static void __queue_work(struct cpu_workqueue_struct *cwq, |
| 264 | struct work_struct *work) |
| 265 | { |
| 266 | unsigned long flags; |
| 267 | |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 268 | debug_work_activate(work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 269 | spin_lock_irqsave(&cwq->lock, flags); |
Oleg Nesterov | 1a4d9b0 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 270 | insert_work(cwq, work, &cwq->worklist); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | spin_unlock_irqrestore(&cwq->lock, flags); |
| 272 | } |
| 273 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 274 | /** |
| 275 | * queue_work - queue work on a workqueue |
| 276 | * @wq: workqueue to use |
| 277 | * @work: work to queue |
| 278 | * |
Alan Stern | 057647f | 2006-10-28 10:38:58 -0700 | [diff] [blame] | 279 | * Returns 0 if @work was already on a queue, non-zero otherwise. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | * |
Oleg Nesterov | 00dfcaf | 2008-04-29 01:00:27 -0700 | [diff] [blame] | 281 | * We queue the work to the CPU on which it was submitted, but if the CPU dies |
| 282 | * it can be processed by another CPU. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 283 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 284 | int queue_work(struct workqueue_struct *wq, struct work_struct *work) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 285 | { |
Oleg Nesterov | ef1ca23 | 2008-07-25 01:47:53 -0700 | [diff] [blame] | 286 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 287 | |
Oleg Nesterov | ef1ca23 | 2008-07-25 01:47:53 -0700 | [diff] [blame] | 288 | ret = queue_work_on(get_cpu(), wq, work); |
| 289 | put_cpu(); |
| 290 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | return ret; |
| 292 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 293 | EXPORT_SYMBOL_GPL(queue_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 294 | |
Zhang Rui | c1a220e | 2008-07-23 21:28:39 -0700 | [diff] [blame] | 295 | /** |
| 296 | * queue_work_on - queue work on specific cpu |
| 297 | * @cpu: CPU number to execute work on |
| 298 | * @wq: workqueue to use |
| 299 | * @work: work to queue |
| 300 | * |
| 301 | * Returns 0 if @work was already on a queue, non-zero otherwise. |
| 302 | * |
| 303 | * We queue the work to a specific CPU, the caller must ensure it |
| 304 | * can't go away. |
| 305 | */ |
| 306 | int |
| 307 | queue_work_on(int cpu, struct workqueue_struct *wq, struct work_struct *work) |
| 308 | { |
| 309 | int ret = 0; |
| 310 | |
| 311 | if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) { |
| 312 | BUG_ON(!list_empty(&work->entry)); |
| 313 | __queue_work(wq_per_cpu(wq, cpu), work); |
| 314 | ret = 1; |
| 315 | } |
| 316 | return ret; |
| 317 | } |
| 318 | EXPORT_SYMBOL_GPL(queue_work_on); |
| 319 | |
Li Zefan | 6d141c3 | 2008-02-08 04:21:09 -0800 | [diff] [blame] | 320 | static void delayed_work_timer_fn(unsigned long __data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 321 | { |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 322 | struct delayed_work *dwork = (struct delayed_work *)__data; |
Oleg Nesterov | ed7c0fe | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 323 | struct cpu_workqueue_struct *cwq = get_wq_data(&dwork->work); |
| 324 | struct workqueue_struct *wq = cwq->wq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | |
Oleg Nesterov | a848e3b | 2007-05-09 02:34:17 -0700 | [diff] [blame] | 326 | __queue_work(wq_per_cpu(wq, smp_processor_id()), &dwork->work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 327 | } |
| 328 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 329 | /** |
| 330 | * queue_delayed_work - queue work on a workqueue after delay |
| 331 | * @wq: workqueue to use |
Randy Dunlap | af9997e | 2006-12-22 01:06:52 -0800 | [diff] [blame] | 332 | * @dwork: delayable work to queue |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 333 | * @delay: number of jiffies to wait before queueing |
| 334 | * |
Alan Stern | 057647f | 2006-10-28 10:38:58 -0700 | [diff] [blame] | 335 | * 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] | 336 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 337 | int queue_delayed_work(struct workqueue_struct *wq, |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 338 | struct delayed_work *dwork, unsigned long delay) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | { |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 340 | if (delay == 0) |
Oleg Nesterov | 63bc036 | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 341 | return queue_work(wq, &dwork->work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 342 | |
Oleg Nesterov | 63bc036 | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 343 | return queue_delayed_work_on(-1, wq, dwork, delay); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 344 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 345 | EXPORT_SYMBOL_GPL(queue_delayed_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 346 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 347 | /** |
| 348 | * queue_delayed_work_on - queue work on specific CPU after delay |
| 349 | * @cpu: CPU number to execute work on |
| 350 | * @wq: workqueue to use |
Randy Dunlap | af9997e | 2006-12-22 01:06:52 -0800 | [diff] [blame] | 351 | * @dwork: work to queue |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 352 | * @delay: number of jiffies to wait before queueing |
| 353 | * |
Alan Stern | 057647f | 2006-10-28 10:38:58 -0700 | [diff] [blame] | 354 | * 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] | 355 | */ |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 356 | int queue_delayed_work_on(int cpu, struct workqueue_struct *wq, |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 357 | struct delayed_work *dwork, unsigned long delay) |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 358 | { |
| 359 | int ret = 0; |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 360 | struct timer_list *timer = &dwork->timer; |
| 361 | struct work_struct *work = &dwork->work; |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 362 | |
Linus Torvalds | a08727b | 2006-12-16 09:53:50 -0800 | [diff] [blame] | 363 | if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) { |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 364 | BUG_ON(timer_pending(timer)); |
| 365 | BUG_ON(!list_empty(&work->entry)); |
| 366 | |
Andrew Liu | 8a3e77c | 2008-05-01 04:35:14 -0700 | [diff] [blame] | 367 | timer_stats_timer_set_start_info(&dwork->timer); |
| 368 | |
Oleg Nesterov | ed7c0fe | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 369 | /* This stores cwq for the moment, for the timer_fn */ |
Oleg Nesterov | a848e3b | 2007-05-09 02:34:17 -0700 | [diff] [blame] | 370 | set_wq_data(work, wq_per_cpu(wq, raw_smp_processor_id())); |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 371 | timer->expires = jiffies + delay; |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 372 | timer->data = (unsigned long)dwork; |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 373 | timer->function = delayed_work_timer_fn; |
Oleg Nesterov | 63bc036 | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 374 | |
| 375 | if (unlikely(cpu >= 0)) |
| 376 | add_timer_on(timer, cpu); |
| 377 | else |
| 378 | add_timer(timer); |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 379 | ret = 1; |
| 380 | } |
| 381 | return ret; |
| 382 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 383 | EXPORT_SYMBOL_GPL(queue_delayed_work_on); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 384 | |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 385 | static void run_workqueue(struct cpu_workqueue_struct *cwq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | { |
Oleg Nesterov | f293ea9 | 2007-05-09 02:34:10 -0700 | [diff] [blame] | 387 | spin_lock_irq(&cwq->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | while (!list_empty(&cwq->worklist)) { |
| 389 | struct work_struct *work = list_entry(cwq->worklist.next, |
| 390 | struct work_struct, entry); |
David Howells | 6bb49e5 | 2006-11-22 14:54:45 +0000 | [diff] [blame] | 391 | work_func_t f = work->func; |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 392 | #ifdef CONFIG_LOCKDEP |
| 393 | /* |
| 394 | * It is permissible to free the struct work_struct |
| 395 | * from inside the function that is called from it, |
| 396 | * this we need to take into account for lockdep too. |
| 397 | * To avoid bogus "held lock freed" warnings as well |
| 398 | * as problems when looking into work->lockdep_map, |
| 399 | * make a copy and use that here. |
| 400 | */ |
| 401 | struct lockdep_map lockdep_map = work->lockdep_map; |
| 402 | #endif |
Frederic Weisbecker | e1d8aa9 | 2009-01-12 23:15:46 +0100 | [diff] [blame] | 403 | trace_workqueue_execution(cwq->thread, work); |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 404 | debug_work_deactivate(work); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 405 | cwq->current_work = work; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 406 | list_del_init(cwq->worklist.next); |
Oleg Nesterov | f293ea9 | 2007-05-09 02:34:10 -0700 | [diff] [blame] | 407 | spin_unlock_irq(&cwq->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | |
David Howells | 365970a | 2006-11-22 14:54:49 +0000 | [diff] [blame] | 409 | BUG_ON(get_wq_data(work) != cwq); |
Oleg Nesterov | 23b2e59 | 2007-05-09 02:34:19 -0700 | [diff] [blame] | 410 | work_clear_pending(work); |
Ingo Molnar | 3295f0e | 2008-08-11 10:30:30 +0200 | [diff] [blame] | 411 | lock_map_acquire(&cwq->wq->lockdep_map); |
| 412 | lock_map_acquire(&lockdep_map); |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 413 | f(work); |
Ingo Molnar | 3295f0e | 2008-08-11 10:30:30 +0200 | [diff] [blame] | 414 | lock_map_release(&lockdep_map); |
| 415 | lock_map_release(&cwq->wq->lockdep_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 416 | |
Peter Zijlstra | d5abe66 | 2006-12-06 20:37:26 -0800 | [diff] [blame] | 417 | if (unlikely(in_atomic() || lockdep_depth(current) > 0)) { |
| 418 | printk(KERN_ERR "BUG: workqueue leaked lock or atomic: " |
| 419 | "%s/0x%08x/%d\n", |
| 420 | current->comm, preempt_count(), |
Pavel Emelyanov | ba25f9d | 2007-10-18 23:40:40 -0700 | [diff] [blame] | 421 | task_pid_nr(current)); |
Peter Zijlstra | d5abe66 | 2006-12-06 20:37:26 -0800 | [diff] [blame] | 422 | printk(KERN_ERR " last function: "); |
| 423 | print_symbol("%s\n", (unsigned long)f); |
| 424 | debug_show_held_locks(current); |
| 425 | dump_stack(); |
| 426 | } |
| 427 | |
Oleg Nesterov | f293ea9 | 2007-05-09 02:34:10 -0700 | [diff] [blame] | 428 | spin_lock_irq(&cwq->lock); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 429 | cwq->current_work = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 430 | } |
Oleg Nesterov | f293ea9 | 2007-05-09 02:34:10 -0700 | [diff] [blame] | 431 | spin_unlock_irq(&cwq->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | } |
| 433 | |
| 434 | static int worker_thread(void *__cwq) |
| 435 | { |
| 436 | struct cpu_workqueue_struct *cwq = __cwq; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 437 | DEFINE_WAIT(wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 438 | |
Rafael J. Wysocki | 8314418 | 2007-07-17 04:03:35 -0700 | [diff] [blame] | 439 | if (cwq->wq->freezeable) |
| 440 | set_freezable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 442 | for (;;) { |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 443 | prepare_to_wait(&cwq->more_work, &wait, TASK_INTERRUPTIBLE); |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 444 | if (!freezing(current) && |
| 445 | !kthread_should_stop() && |
| 446 | list_empty(&cwq->worklist)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 447 | schedule(); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 448 | finish_wait(&cwq->more_work, &wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | |
Oleg Nesterov | 85f4186 | 2007-05-09 02:34:20 -0700 | [diff] [blame] | 450 | try_to_freeze(); |
| 451 | |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 452 | if (kthread_should_stop()) |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 453 | break; |
| 454 | |
| 455 | run_workqueue(cwq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | } |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 457 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | return 0; |
| 459 | } |
| 460 | |
Oleg Nesterov | fc2e4d7 | 2007-05-09 02:33:51 -0700 | [diff] [blame] | 461 | struct wq_barrier { |
| 462 | struct work_struct work; |
| 463 | struct completion done; |
| 464 | }; |
| 465 | |
| 466 | static void wq_barrier_func(struct work_struct *work) |
| 467 | { |
| 468 | struct wq_barrier *barr = container_of(work, struct wq_barrier, work); |
| 469 | complete(&barr->done); |
| 470 | } |
| 471 | |
Oleg Nesterov | 83c2252 | 2007-05-09 02:33:54 -0700 | [diff] [blame] | 472 | static void insert_wq_barrier(struct cpu_workqueue_struct *cwq, |
Oleg Nesterov | 1a4d9b0 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 473 | struct wq_barrier *barr, struct list_head *head) |
Oleg Nesterov | fc2e4d7 | 2007-05-09 02:33:51 -0700 | [diff] [blame] | 474 | { |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 475 | /* |
| 476 | * debugobject calls are safe here even with cwq->lock locked |
| 477 | * as we know for sure that this will not trigger any of the |
| 478 | * checks and call back into the fixup functions where we |
| 479 | * might deadlock. |
| 480 | */ |
| 481 | INIT_WORK_ON_STACK(&barr->work, wq_barrier_func); |
Oleg Nesterov | fc2e4d7 | 2007-05-09 02:33:51 -0700 | [diff] [blame] | 482 | __set_bit(WORK_STRUCT_PENDING, work_data_bits(&barr->work)); |
| 483 | |
| 484 | init_completion(&barr->done); |
Oleg Nesterov | 83c2252 | 2007-05-09 02:33:54 -0700 | [diff] [blame] | 485 | |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 486 | debug_work_activate(&barr->work); |
Oleg Nesterov | 1a4d9b0 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 487 | insert_work(cwq, &barr->work, head); |
Oleg Nesterov | fc2e4d7 | 2007-05-09 02:33:51 -0700 | [diff] [blame] | 488 | } |
| 489 | |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 490 | static int flush_cpu_workqueue(struct cpu_workqueue_struct *cwq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 491 | { |
Lai Jiangshan | 2355b70 | 2009-04-02 16:58:24 -0700 | [diff] [blame] | 492 | int active = 0; |
| 493 | struct wq_barrier barr; |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 494 | |
Lai Jiangshan | 2355b70 | 2009-04-02 16:58:24 -0700 | [diff] [blame] | 495 | WARN_ON(cwq->thread == current); |
| 496 | |
| 497 | spin_lock_irq(&cwq->lock); |
| 498 | if (!list_empty(&cwq->worklist) || cwq->current_work != NULL) { |
| 499 | insert_wq_barrier(cwq, &barr, &cwq->worklist); |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 500 | active = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 501 | } |
Lai Jiangshan | 2355b70 | 2009-04-02 16:58:24 -0700 | [diff] [blame] | 502 | spin_unlock_irq(&cwq->lock); |
| 503 | |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 504 | if (active) { |
Lai Jiangshan | 2355b70 | 2009-04-02 16:58:24 -0700 | [diff] [blame] | 505 | wait_for_completion(&barr.done); |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 506 | destroy_work_on_stack(&barr.work); |
| 507 | } |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 508 | |
| 509 | return active; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 510 | } |
| 511 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 512 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 513 | * flush_workqueue - ensure that any scheduled work has run to completion. |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 514 | * @wq: workqueue to flush |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 515 | * |
| 516 | * Forces execution of the workqueue and blocks until its completion. |
| 517 | * This is typically used in driver shutdown handlers. |
| 518 | * |
Oleg Nesterov | fc2e4d7 | 2007-05-09 02:33:51 -0700 | [diff] [blame] | 519 | * We sleep until all works which were queued on entry have been handled, |
| 520 | * but we are not livelocked by new incoming ones. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 521 | * |
| 522 | * This function used to run the workqueues itself. Now we just wait for the |
| 523 | * helper threads to do it. |
| 524 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 525 | void flush_workqueue(struct workqueue_struct *wq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 526 | { |
Rusty Russell | e7577c5 | 2009-01-01 10:12:25 +1030 | [diff] [blame] | 527 | const struct cpumask *cpu_map = wq_cpu_map(wq); |
Oleg Nesterov | cce1a16 | 2007-05-09 02:34:13 -0700 | [diff] [blame] | 528 | int cpu; |
Oleg Nesterov | b1f4ec17 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 529 | |
Oleg Nesterov | f293ea9 | 2007-05-09 02:34:10 -0700 | [diff] [blame] | 530 | might_sleep(); |
Ingo Molnar | 3295f0e | 2008-08-11 10:30:30 +0200 | [diff] [blame] | 531 | lock_map_acquire(&wq->lockdep_map); |
| 532 | lock_map_release(&wq->lockdep_map); |
Rusty Russell | aa85ea5 | 2009-03-30 22:05:15 -0600 | [diff] [blame] | 533 | for_each_cpu(cpu, cpu_map) |
Oleg Nesterov | b1f4ec17 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 534 | flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 535 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 536 | EXPORT_SYMBOL_GPL(flush_workqueue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | |
Oleg Nesterov | db70089 | 2008-07-25 01:47:49 -0700 | [diff] [blame] | 538 | /** |
| 539 | * flush_work - block until a work_struct's callback has terminated |
| 540 | * @work: the work which is to be flushed |
| 541 | * |
Oleg Nesterov | a67da70 | 2008-07-25 01:47:52 -0700 | [diff] [blame] | 542 | * Returns false if @work has already terminated. |
| 543 | * |
Oleg Nesterov | db70089 | 2008-07-25 01:47:49 -0700 | [diff] [blame] | 544 | * It is expected that, prior to calling flush_work(), the caller has |
| 545 | * arranged for the work to not be requeued, otherwise it doesn't make |
| 546 | * sense to use this function. |
| 547 | */ |
| 548 | int flush_work(struct work_struct *work) |
| 549 | { |
| 550 | struct cpu_workqueue_struct *cwq; |
| 551 | struct list_head *prev; |
| 552 | struct wq_barrier barr; |
| 553 | |
| 554 | might_sleep(); |
| 555 | cwq = get_wq_data(work); |
| 556 | if (!cwq) |
| 557 | return 0; |
| 558 | |
Ingo Molnar | 3295f0e | 2008-08-11 10:30:30 +0200 | [diff] [blame] | 559 | lock_map_acquire(&cwq->wq->lockdep_map); |
| 560 | lock_map_release(&cwq->wq->lockdep_map); |
Oleg Nesterov | a67da70 | 2008-07-25 01:47:52 -0700 | [diff] [blame] | 561 | |
Oleg Nesterov | db70089 | 2008-07-25 01:47:49 -0700 | [diff] [blame] | 562 | prev = NULL; |
| 563 | spin_lock_irq(&cwq->lock); |
| 564 | if (!list_empty(&work->entry)) { |
| 565 | /* |
| 566 | * See the comment near try_to_grab_pending()->smp_rmb(). |
| 567 | * If it was re-queued under us we are not going to wait. |
| 568 | */ |
| 569 | smp_rmb(); |
| 570 | if (unlikely(cwq != get_wq_data(work))) |
| 571 | goto out; |
| 572 | prev = &work->entry; |
| 573 | } else { |
| 574 | if (cwq->current_work != work) |
| 575 | goto out; |
| 576 | prev = &cwq->worklist; |
| 577 | } |
| 578 | insert_wq_barrier(cwq, &barr, prev->next); |
| 579 | out: |
| 580 | spin_unlock_irq(&cwq->lock); |
| 581 | if (!prev) |
| 582 | return 0; |
| 583 | |
| 584 | wait_for_completion(&barr.done); |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 585 | destroy_work_on_stack(&barr.work); |
Oleg Nesterov | db70089 | 2008-07-25 01:47:49 -0700 | [diff] [blame] | 586 | return 1; |
| 587 | } |
| 588 | EXPORT_SYMBOL_GPL(flush_work); |
| 589 | |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 590 | /* |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 591 | * Upon a successful return (>= 0), the caller "owns" WORK_STRUCT_PENDING bit, |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 592 | * so this work can't be re-armed in any way. |
| 593 | */ |
| 594 | static int try_to_grab_pending(struct work_struct *work) |
| 595 | { |
| 596 | struct cpu_workqueue_struct *cwq; |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 597 | int ret = -1; |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 598 | |
| 599 | if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 600 | return 0; |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 601 | |
| 602 | /* |
| 603 | * The queueing is in progress, or it is already queued. Try to |
| 604 | * steal it from ->worklist without clearing WORK_STRUCT_PENDING. |
| 605 | */ |
| 606 | |
| 607 | cwq = get_wq_data(work); |
| 608 | if (!cwq) |
| 609 | return ret; |
| 610 | |
| 611 | spin_lock_irq(&cwq->lock); |
| 612 | if (!list_empty(&work->entry)) { |
| 613 | /* |
| 614 | * This work is queued, but perhaps we locked the wrong cwq. |
| 615 | * In that case we must see the new value after rmb(), see |
| 616 | * insert_work()->wmb(). |
| 617 | */ |
| 618 | smp_rmb(); |
| 619 | if (cwq == get_wq_data(work)) { |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 620 | debug_work_deactivate(work); |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 621 | list_del_init(&work->entry); |
| 622 | ret = 1; |
| 623 | } |
| 624 | } |
| 625 | spin_unlock_irq(&cwq->lock); |
| 626 | |
| 627 | return ret; |
| 628 | } |
| 629 | |
| 630 | static void wait_on_cpu_work(struct cpu_workqueue_struct *cwq, |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 631 | struct work_struct *work) |
| 632 | { |
| 633 | struct wq_barrier barr; |
| 634 | int running = 0; |
| 635 | |
| 636 | spin_lock_irq(&cwq->lock); |
| 637 | if (unlikely(cwq->current_work == work)) { |
Oleg Nesterov | 1a4d9b0 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 638 | insert_wq_barrier(cwq, &barr, cwq->worklist.next); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 639 | running = 1; |
| 640 | } |
| 641 | spin_unlock_irq(&cwq->lock); |
| 642 | |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 643 | if (unlikely(running)) { |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 644 | wait_for_completion(&barr.done); |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 645 | destroy_work_on_stack(&barr.work); |
| 646 | } |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 647 | } |
| 648 | |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 649 | static void wait_on_work(struct work_struct *work) |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 650 | { |
| 651 | struct cpu_workqueue_struct *cwq; |
Oleg Nesterov | 28e53bd | 2007-05-09 02:34:22 -0700 | [diff] [blame] | 652 | struct workqueue_struct *wq; |
Rusty Russell | e7577c5 | 2009-01-01 10:12:25 +1030 | [diff] [blame] | 653 | const struct cpumask *cpu_map; |
Oleg Nesterov | b1f4ec17 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 654 | int cpu; |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 655 | |
Oleg Nesterov | f293ea9 | 2007-05-09 02:34:10 -0700 | [diff] [blame] | 656 | might_sleep(); |
| 657 | |
Ingo Molnar | 3295f0e | 2008-08-11 10:30:30 +0200 | [diff] [blame] | 658 | lock_map_acquire(&work->lockdep_map); |
| 659 | lock_map_release(&work->lockdep_map); |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 660 | |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 661 | cwq = get_wq_data(work); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 662 | if (!cwq) |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 663 | return; |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 664 | |
Oleg Nesterov | 28e53bd | 2007-05-09 02:34:22 -0700 | [diff] [blame] | 665 | wq = cwq->wq; |
| 666 | cpu_map = wq_cpu_map(wq); |
| 667 | |
Rusty Russell | aa85ea5 | 2009-03-30 22:05:15 -0600 | [diff] [blame] | 668 | for_each_cpu(cpu, cpu_map) |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 669 | wait_on_cpu_work(per_cpu_ptr(wq->cpu_wq, cpu), work); |
| 670 | } |
| 671 | |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 672 | static int __cancel_work_timer(struct work_struct *work, |
| 673 | struct timer_list* timer) |
| 674 | { |
| 675 | int ret; |
| 676 | |
| 677 | do { |
| 678 | ret = (timer && likely(del_timer(timer))); |
| 679 | if (!ret) |
| 680 | ret = try_to_grab_pending(work); |
| 681 | wait_on_work(work); |
| 682 | } while (unlikely(ret < 0)); |
| 683 | |
Oleg Nesterov | 4d707b9 | 2010-04-23 17:40:40 +0200 | [diff] [blame] | 684 | clear_wq_data(work); |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 685 | return ret; |
| 686 | } |
| 687 | |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 688 | /** |
| 689 | * cancel_work_sync - block until a work_struct's callback has terminated |
| 690 | * @work: the work which is to be flushed |
| 691 | * |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 692 | * Returns true if @work was pending. |
| 693 | * |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 694 | * cancel_work_sync() will cancel the work if it is queued. If the work's |
| 695 | * callback appears to be running, cancel_work_sync() will block until it |
| 696 | * has completed. |
| 697 | * |
| 698 | * It is possible to use this function if the work re-queues itself. It can |
| 699 | * cancel the work even if it migrates to another workqueue, however in that |
| 700 | * case it only guarantees that work->func() has completed on the last queued |
| 701 | * workqueue. |
| 702 | * |
| 703 | * cancel_work_sync(&delayed_work->work) should be used only if ->timer is not |
| 704 | * pending, otherwise it goes into a busy-wait loop until the timer expires. |
| 705 | * |
| 706 | * The caller must ensure that workqueue_struct on which this work was last |
| 707 | * queued can't be destroyed before this function returns. |
| 708 | */ |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 709 | int cancel_work_sync(struct work_struct *work) |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 710 | { |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 711 | return __cancel_work_timer(work, NULL); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 712 | } |
Oleg Nesterov | 28e53bd | 2007-05-09 02:34:22 -0700 | [diff] [blame] | 713 | EXPORT_SYMBOL_GPL(cancel_work_sync); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 714 | |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 715 | /** |
Oleg Nesterov | f5a421a | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 716 | * cancel_delayed_work_sync - reliably kill off a delayed work. |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 717 | * @dwork: the delayed work struct |
| 718 | * |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 719 | * Returns true if @dwork was pending. |
| 720 | * |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 721 | * It is possible to use this function if @dwork rearms itself via queue_work() |
| 722 | * or queue_delayed_work(). See also the comment for cancel_work_sync(). |
| 723 | */ |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 724 | int cancel_delayed_work_sync(struct delayed_work *dwork) |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 725 | { |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 726 | return __cancel_work_timer(&dwork->work, &dwork->timer); |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 727 | } |
Oleg Nesterov | f5a421a | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 728 | EXPORT_SYMBOL(cancel_delayed_work_sync); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 729 | |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 730 | static struct workqueue_struct *keventd_wq __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 731 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 732 | /** |
| 733 | * schedule_work - put work task in global workqueue |
| 734 | * @work: job to be done |
| 735 | * |
Bart Van Assche | 5b0f437d | 2009-07-30 19:00:53 +0200 | [diff] [blame] | 736 | * Returns zero if @work was already on the kernel-global workqueue and |
| 737 | * non-zero otherwise. |
| 738 | * |
| 739 | * This puts a job in the kernel-global workqueue if it was not already |
| 740 | * queued and leaves it in the same position on the kernel-global |
| 741 | * workqueue otherwise. |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 742 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 743 | int schedule_work(struct work_struct *work) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 744 | { |
| 745 | return queue_work(keventd_wq, work); |
| 746 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 747 | EXPORT_SYMBOL(schedule_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 748 | |
Zhang Rui | c1a220e | 2008-07-23 21:28:39 -0700 | [diff] [blame] | 749 | /* |
| 750 | * schedule_work_on - put work task on a specific cpu |
| 751 | * @cpu: cpu to put the work task on |
| 752 | * @work: job to be done |
| 753 | * |
| 754 | * This puts a job on a specific cpu |
| 755 | */ |
| 756 | int schedule_work_on(int cpu, struct work_struct *work) |
| 757 | { |
| 758 | return queue_work_on(cpu, keventd_wq, work); |
| 759 | } |
| 760 | EXPORT_SYMBOL(schedule_work_on); |
| 761 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 762 | /** |
| 763 | * schedule_delayed_work - put work task in global workqueue after delay |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 764 | * @dwork: job to be done |
| 765 | * @delay: number of jiffies to wait or 0 for immediate execution |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 766 | * |
| 767 | * After waiting for a given time this puts a job in the kernel-global |
| 768 | * workqueue. |
| 769 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 770 | int schedule_delayed_work(struct delayed_work *dwork, |
Ingo Molnar | 82f67cd | 2007-02-16 01:28:13 -0800 | [diff] [blame] | 771 | unsigned long delay) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 772 | { |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 773 | return queue_delayed_work(keventd_wq, dwork, delay); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 774 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 775 | EXPORT_SYMBOL(schedule_delayed_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 776 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 777 | /** |
Linus Torvalds | 8c53e46 | 2009-10-14 09:16:42 -0700 | [diff] [blame] | 778 | * flush_delayed_work - block until a dwork_struct's callback has terminated |
| 779 | * @dwork: the delayed work which is to be flushed |
| 780 | * |
| 781 | * Any timeout is cancelled, and any pending work is run immediately. |
| 782 | */ |
| 783 | void flush_delayed_work(struct delayed_work *dwork) |
| 784 | { |
| 785 | if (del_timer_sync(&dwork->timer)) { |
| 786 | struct cpu_workqueue_struct *cwq; |
Oleg Nesterov | 47dd5be | 2010-04-30 07:23:51 +0200 | [diff] [blame] | 787 | cwq = wq_per_cpu(get_wq_data(&dwork->work)->wq, get_cpu()); |
Linus Torvalds | 8c53e46 | 2009-10-14 09:16:42 -0700 | [diff] [blame] | 788 | __queue_work(cwq, &dwork->work); |
| 789 | put_cpu(); |
| 790 | } |
| 791 | flush_work(&dwork->work); |
| 792 | } |
| 793 | EXPORT_SYMBOL(flush_delayed_work); |
| 794 | |
| 795 | /** |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 796 | * schedule_delayed_work_on - queue work in global workqueue on CPU after delay |
| 797 | * @cpu: cpu to use |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 798 | * @dwork: job to be done |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 799 | * @delay: number of jiffies to wait |
| 800 | * |
| 801 | * After waiting for a given time this puts a job in the kernel-global |
| 802 | * workqueue on the specified CPU. |
| 803 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 804 | int schedule_delayed_work_on(int cpu, |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 805 | struct delayed_work *dwork, unsigned long delay) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 806 | { |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 807 | return queue_delayed_work_on(cpu, keventd_wq, dwork, delay); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 809 | EXPORT_SYMBOL(schedule_delayed_work_on); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 810 | |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 811 | /** |
| 812 | * schedule_on_each_cpu - call a function on each online CPU from keventd |
| 813 | * @func: the function to call |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 814 | * |
| 815 | * Returns zero on success. |
| 816 | * Returns -ve errno on failure. |
| 817 | * |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 818 | * schedule_on_each_cpu() is very slow. |
| 819 | */ |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 820 | int schedule_on_each_cpu(work_func_t func) |
Christoph Lameter | 15316ba | 2006-01-08 01:00:43 -0800 | [diff] [blame] | 821 | { |
| 822 | int cpu; |
Andi Kleen | 65a6446 | 2009-10-14 06:22:47 +0200 | [diff] [blame] | 823 | int orig = -1; |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 824 | struct work_struct *works; |
Christoph Lameter | 15316ba | 2006-01-08 01:00:43 -0800 | [diff] [blame] | 825 | |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 826 | works = alloc_percpu(struct work_struct); |
| 827 | if (!works) |
Christoph Lameter | 15316ba | 2006-01-08 01:00:43 -0800 | [diff] [blame] | 828 | return -ENOMEM; |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 829 | |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 830 | get_online_cpus(); |
Tejun Heo | 9398180 | 2009-11-17 14:06:20 -0800 | [diff] [blame] | 831 | |
| 832 | /* |
| 833 | * When running in keventd don't schedule a work item on |
| 834 | * itself. Can just call directly because the work queue is |
| 835 | * already bound. This also is faster. |
| 836 | */ |
| 837 | if (current_is_keventd()) |
| 838 | orig = raw_smp_processor_id(); |
| 839 | |
Christoph Lameter | 15316ba | 2006-01-08 01:00:43 -0800 | [diff] [blame] | 840 | for_each_online_cpu(cpu) { |
Ingo Molnar | 9bfb183 | 2006-12-18 20:05:09 +0100 | [diff] [blame] | 841 | struct work_struct *work = per_cpu_ptr(works, cpu); |
| 842 | |
| 843 | INIT_WORK(work, func); |
Andi Kleen | 65a6446 | 2009-10-14 06:22:47 +0200 | [diff] [blame] | 844 | if (cpu != orig) |
Tejun Heo | 9398180 | 2009-11-17 14:06:20 -0800 | [diff] [blame] | 845 | schedule_work_on(cpu, work); |
Andi Kleen | 65a6446 | 2009-10-14 06:22:47 +0200 | [diff] [blame] | 846 | } |
Tejun Heo | 9398180 | 2009-11-17 14:06:20 -0800 | [diff] [blame] | 847 | if (orig >= 0) |
| 848 | func(per_cpu_ptr(works, orig)); |
| 849 | |
| 850 | for_each_online_cpu(cpu) |
| 851 | flush_work(per_cpu_ptr(works, cpu)); |
| 852 | |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 853 | put_online_cpus(); |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 854 | free_percpu(works); |
Christoph Lameter | 15316ba | 2006-01-08 01:00:43 -0800 | [diff] [blame] | 855 | return 0; |
| 856 | } |
| 857 | |
Alan Stern | eef6a7d | 2010-02-12 17:39:21 +0900 | [diff] [blame] | 858 | /** |
| 859 | * flush_scheduled_work - ensure that any scheduled work has run to completion. |
| 860 | * |
| 861 | * Forces execution of the kernel-global workqueue and blocks until its |
| 862 | * completion. |
| 863 | * |
| 864 | * Think twice before calling this function! It's very easy to get into |
| 865 | * trouble if you don't take great care. Either of the following situations |
| 866 | * will lead to deadlock: |
| 867 | * |
| 868 | * One of the work items currently on the workqueue needs to acquire |
| 869 | * a lock held by your code or its caller. |
| 870 | * |
| 871 | * Your code is running in the context of a work routine. |
| 872 | * |
| 873 | * They will be detected by lockdep when they occur, but the first might not |
| 874 | * occur very often. It depends on what work items are on the workqueue and |
| 875 | * what locks they need, which you have no control over. |
| 876 | * |
| 877 | * In most situations flushing the entire workqueue is overkill; you merely |
| 878 | * need to know that a particular work item isn't queued and isn't running. |
| 879 | * In such cases you should use cancel_delayed_work_sync() or |
| 880 | * cancel_work_sync() instead. |
| 881 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 882 | void flush_scheduled_work(void) |
| 883 | { |
| 884 | flush_workqueue(keventd_wq); |
| 885 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 886 | EXPORT_SYMBOL(flush_scheduled_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 887 | |
| 888 | /** |
James Bottomley | 1fa44ec | 2006-02-23 12:43:43 -0600 | [diff] [blame] | 889 | * execute_in_process_context - reliably execute the routine with user context |
| 890 | * @fn: the function to execute |
James Bottomley | 1fa44ec | 2006-02-23 12:43:43 -0600 | [diff] [blame] | 891 | * @ew: guaranteed storage for the execute work structure (must |
| 892 | * be available when the work executes) |
| 893 | * |
| 894 | * Executes the function immediately if process context is available, |
| 895 | * otherwise schedules the function for delayed execution. |
| 896 | * |
| 897 | * Returns: 0 - function was executed |
| 898 | * 1 - function was scheduled for execution |
| 899 | */ |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 900 | 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] | 901 | { |
| 902 | if (!in_interrupt()) { |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 903 | fn(&ew->work); |
James Bottomley | 1fa44ec | 2006-02-23 12:43:43 -0600 | [diff] [blame] | 904 | return 0; |
| 905 | } |
| 906 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 907 | INIT_WORK(&ew->work, fn); |
James Bottomley | 1fa44ec | 2006-02-23 12:43:43 -0600 | [diff] [blame] | 908 | schedule_work(&ew->work); |
| 909 | |
| 910 | return 1; |
| 911 | } |
| 912 | EXPORT_SYMBOL_GPL(execute_in_process_context); |
| 913 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 914 | int keventd_up(void) |
| 915 | { |
| 916 | return keventd_wq != NULL; |
| 917 | } |
| 918 | |
| 919 | int current_is_keventd(void) |
| 920 | { |
| 921 | struct cpu_workqueue_struct *cwq; |
Hugh Dickins | d243769 | 2007-08-27 16:06:19 +0100 | [diff] [blame] | 922 | int cpu = raw_smp_processor_id(); /* preempt-safe: keventd is per-cpu */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 923 | int ret = 0; |
| 924 | |
| 925 | BUG_ON(!keventd_wq); |
| 926 | |
Christoph Lameter | 89ada67 | 2005-10-30 15:01:59 -0800 | [diff] [blame] | 927 | cwq = per_cpu_ptr(keventd_wq->cpu_wq, cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 928 | if (current == cwq->thread) |
| 929 | ret = 1; |
| 930 | |
| 931 | return ret; |
| 932 | |
| 933 | } |
| 934 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 935 | static struct cpu_workqueue_struct * |
| 936 | init_cpu_workqueue(struct workqueue_struct *wq, int cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 937 | { |
Christoph Lameter | 89ada67 | 2005-10-30 15:01:59 -0800 | [diff] [blame] | 938 | struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 939 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 940 | cwq->wq = wq; |
| 941 | spin_lock_init(&cwq->lock); |
| 942 | INIT_LIST_HEAD(&cwq->worklist); |
| 943 | init_waitqueue_head(&cwq->more_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 944 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 945 | return cwq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 946 | } |
| 947 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 948 | static int create_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 949 | { |
Heiko Carstens | 0d557dc | 2008-10-13 23:50:09 +0200 | [diff] [blame] | 950 | struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 }; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 951 | struct workqueue_struct *wq = cwq->wq; |
David Howells | 6cc88bc | 2008-11-14 10:39:21 +1100 | [diff] [blame] | 952 | const char *fmt = is_wq_single_threaded(wq) ? "%s" : "%s/%d"; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 953 | struct task_struct *p; |
| 954 | |
| 955 | p = kthread_create(worker_thread, cwq, fmt, wq->name, cpu); |
| 956 | /* |
| 957 | * Nobody can add the work_struct to this cwq, |
| 958 | * if (caller is __create_workqueue) |
| 959 | * nobody should see this wq |
| 960 | * else // caller is CPU_UP_PREPARE |
| 961 | * cpu is not on cpu_online_map |
| 962 | * so we can abort safely. |
| 963 | */ |
| 964 | if (IS_ERR(p)) |
| 965 | return PTR_ERR(p); |
Heiko Carstens | 0d557dc | 2008-10-13 23:50:09 +0200 | [diff] [blame] | 966 | if (cwq->wq->rt) |
| 967 | sched_setscheduler_nocheck(p, SCHED_FIFO, ¶m); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 968 | cwq->thread = p; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 969 | |
Frederic Weisbecker | e1d8aa9 | 2009-01-12 23:15:46 +0100 | [diff] [blame] | 970 | trace_workqueue_creation(cwq->thread, cpu); |
| 971 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 972 | return 0; |
| 973 | } |
| 974 | |
Oleg Nesterov | 06ba38a | 2007-05-09 02:34:15 -0700 | [diff] [blame] | 975 | static void start_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu) |
| 976 | { |
| 977 | struct task_struct *p = cwq->thread; |
| 978 | |
| 979 | if (p != NULL) { |
| 980 | if (cpu >= 0) |
| 981 | kthread_bind(p, cpu); |
| 982 | wake_up_process(p); |
| 983 | } |
| 984 | } |
| 985 | |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 986 | struct workqueue_struct *__create_workqueue_key(const char *name, |
| 987 | int singlethread, |
| 988 | int freezeable, |
Heiko Carstens | 0d557dc | 2008-10-13 23:50:09 +0200 | [diff] [blame] | 989 | int rt, |
Johannes Berg | eb13ba8 | 2008-01-16 09:51:58 +0100 | [diff] [blame] | 990 | struct lock_class_key *key, |
| 991 | const char *lock_name) |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 992 | { |
| 993 | struct workqueue_struct *wq; |
| 994 | struct cpu_workqueue_struct *cwq; |
| 995 | int err = 0, cpu; |
| 996 | |
| 997 | wq = kzalloc(sizeof(*wq), GFP_KERNEL); |
| 998 | if (!wq) |
| 999 | return NULL; |
| 1000 | |
| 1001 | wq->cpu_wq = alloc_percpu(struct cpu_workqueue_struct); |
| 1002 | if (!wq->cpu_wq) { |
| 1003 | kfree(wq); |
| 1004 | return NULL; |
| 1005 | } |
| 1006 | |
| 1007 | wq->name = name; |
Johannes Berg | eb13ba8 | 2008-01-16 09:51:58 +0100 | [diff] [blame] | 1008 | lockdep_init_map(&wq->lockdep_map, lock_name, key, 0); |
Oleg Nesterov | cce1a16 | 2007-05-09 02:34:13 -0700 | [diff] [blame] | 1009 | wq->singlethread = singlethread; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1010 | wq->freezeable = freezeable; |
Heiko Carstens | 0d557dc | 2008-10-13 23:50:09 +0200 | [diff] [blame] | 1011 | wq->rt = rt; |
Oleg Nesterov | cce1a16 | 2007-05-09 02:34:13 -0700 | [diff] [blame] | 1012 | INIT_LIST_HEAD(&wq->list); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1013 | |
| 1014 | if (singlethread) { |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1015 | cwq = init_cpu_workqueue(wq, singlethread_cpu); |
| 1016 | err = create_workqueue_thread(cwq, singlethread_cpu); |
Oleg Nesterov | 06ba38a | 2007-05-09 02:34:15 -0700 | [diff] [blame] | 1017 | start_workqueue_thread(cwq, -1); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1018 | } else { |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 1019 | cpu_maps_update_begin(); |
Oleg Nesterov | 6af8bf3 | 2008-07-29 22:33:49 -0700 | [diff] [blame] | 1020 | /* |
| 1021 | * We must place this wq on list even if the code below fails. |
| 1022 | * cpu_down(cpu) can remove cpu from cpu_populated_map before |
| 1023 | * destroy_workqueue() takes the lock, in that case we leak |
| 1024 | * cwq[cpu]->thread. |
| 1025 | */ |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 1026 | spin_lock(&workqueue_lock); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1027 | list_add(&wq->list, &workqueues); |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 1028 | spin_unlock(&workqueue_lock); |
Oleg Nesterov | 6af8bf3 | 2008-07-29 22:33:49 -0700 | [diff] [blame] | 1029 | /* |
| 1030 | * We must initialize cwqs for each possible cpu even if we |
| 1031 | * are going to call destroy_workqueue() finally. Otherwise |
| 1032 | * cpu_up() can hit the uninitialized cwq once we drop the |
| 1033 | * lock. |
| 1034 | */ |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1035 | for_each_possible_cpu(cpu) { |
| 1036 | cwq = init_cpu_workqueue(wq, cpu); |
| 1037 | if (err || !cpu_online(cpu)) |
| 1038 | continue; |
| 1039 | err = create_workqueue_thread(cwq, cpu); |
Oleg Nesterov | 06ba38a | 2007-05-09 02:34:15 -0700 | [diff] [blame] | 1040 | start_workqueue_thread(cwq, cpu); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1041 | } |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 1042 | cpu_maps_update_done(); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1043 | } |
| 1044 | |
| 1045 | if (err) { |
| 1046 | destroy_workqueue(wq); |
| 1047 | wq = NULL; |
| 1048 | } |
| 1049 | return wq; |
| 1050 | } |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 1051 | EXPORT_SYMBOL_GPL(__create_workqueue_key); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1052 | |
Oleg Nesterov | 1e35eaa2 | 2008-04-29 01:00:28 -0700 | [diff] [blame] | 1053 | static void cleanup_workqueue_thread(struct cpu_workqueue_struct *cwq) |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1054 | { |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 1055 | /* |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 1056 | * Our caller is either destroy_workqueue() or CPU_POST_DEAD, |
| 1057 | * cpu_add_remove_lock protects cwq->thread. |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 1058 | */ |
| 1059 | if (cwq->thread == NULL) |
| 1060 | return; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1061 | |
Ingo Molnar | 3295f0e | 2008-08-11 10:30:30 +0200 | [diff] [blame] | 1062 | lock_map_acquire(&cwq->wq->lockdep_map); |
| 1063 | lock_map_release(&cwq->wq->lockdep_map); |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 1064 | |
Oleg Nesterov | 13c2216 | 2007-07-17 04:03:55 -0700 | [diff] [blame] | 1065 | flush_cpu_workqueue(cwq); |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 1066 | /* |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 1067 | * 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] | 1068 | * a concurrent flush_workqueue() can insert a barrier after us. |
| 1069 | * However, in that case run_workqueue() won't return and check |
| 1070 | * kthread_should_stop() until it flushes all work_struct's. |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 1071 | * When ->worklist becomes empty it is safe to exit because no |
| 1072 | * more work_structs can be queued on this cwq: flush_workqueue |
| 1073 | * checks list_empty(), and a "normal" queue_work() can't use |
| 1074 | * a dead CPU. |
| 1075 | */ |
Frederic Weisbecker | e1d8aa9 | 2009-01-12 23:15:46 +0100 | [diff] [blame] | 1076 | trace_workqueue_destruction(cwq->thread); |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 1077 | kthread_stop(cwq->thread); |
| 1078 | cwq->thread = NULL; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1079 | } |
| 1080 | |
| 1081 | /** |
| 1082 | * destroy_workqueue - safely terminate a workqueue |
| 1083 | * @wq: target workqueue |
| 1084 | * |
| 1085 | * Safely destroy a workqueue. All work currently pending will be done first. |
| 1086 | */ |
| 1087 | void destroy_workqueue(struct workqueue_struct *wq) |
| 1088 | { |
Rusty Russell | e7577c5 | 2009-01-01 10:12:25 +1030 | [diff] [blame] | 1089 | const struct cpumask *cpu_map = wq_cpu_map(wq); |
Oleg Nesterov | b1f4ec17 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 1090 | int cpu; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1091 | |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 1092 | cpu_maps_update_begin(); |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 1093 | spin_lock(&workqueue_lock); |
Oleg Nesterov | b1f4ec17 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 1094 | list_del(&wq->list); |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 1095 | spin_unlock(&workqueue_lock); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1096 | |
Rusty Russell | aa85ea5 | 2009-03-30 22:05:15 -0600 | [diff] [blame] | 1097 | for_each_cpu(cpu, cpu_map) |
Oleg Nesterov | 1e35eaa2 | 2008-04-29 01:00:28 -0700 | [diff] [blame] | 1098 | cleanup_workqueue_thread(per_cpu_ptr(wq->cpu_wq, cpu)); |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 1099 | cpu_maps_update_done(); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1100 | |
| 1101 | free_percpu(wq->cpu_wq); |
| 1102 | kfree(wq); |
| 1103 | } |
| 1104 | EXPORT_SYMBOL_GPL(destroy_workqueue); |
| 1105 | |
| 1106 | static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, |
| 1107 | unsigned long action, |
| 1108 | void *hcpu) |
| 1109 | { |
| 1110 | unsigned int cpu = (unsigned long)hcpu; |
| 1111 | struct cpu_workqueue_struct *cwq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1112 | struct workqueue_struct *wq; |
Akinobu Mita | 80b5184 | 2010-05-26 14:43:32 -0700 | [diff] [blame] | 1113 | int err = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1114 | |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 1115 | action &= ~CPU_TASKS_FROZEN; |
| 1116 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1117 | switch (action) { |
| 1118 | case CPU_UP_PREPARE: |
Rusty Russell | e7577c5 | 2009-01-01 10:12:25 +1030 | [diff] [blame] | 1119 | cpumask_set_cpu(cpu, cpu_populated_map); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1120 | } |
Oleg Nesterov | 8448502 | 2008-07-25 01:47:54 -0700 | [diff] [blame] | 1121 | undo: |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1122 | list_for_each_entry(wq, &workqueues, list) { |
| 1123 | cwq = per_cpu_ptr(wq->cpu_wq, cpu); |
Christoph Lameter | 89ada67 | 2005-10-30 15:01:59 -0800 | [diff] [blame] | 1124 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1125 | switch (action) { |
| 1126 | case CPU_UP_PREPARE: |
Akinobu Mita | 80b5184 | 2010-05-26 14:43:32 -0700 | [diff] [blame] | 1127 | err = create_workqueue_thread(cwq, cpu); |
| 1128 | if (!err) |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1129 | break; |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 1130 | printk(KERN_ERR "workqueue [%s] for %i failed\n", |
| 1131 | wq->name, cpu); |
Oleg Nesterov | 8448502 | 2008-07-25 01:47:54 -0700 | [diff] [blame] | 1132 | action = CPU_UP_CANCELED; |
Akinobu Mita | 80b5184 | 2010-05-26 14:43:32 -0700 | [diff] [blame] | 1133 | err = -ENOMEM; |
Oleg Nesterov | 8448502 | 2008-07-25 01:47:54 -0700 | [diff] [blame] | 1134 | goto undo; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1135 | |
| 1136 | case CPU_ONLINE: |
Oleg Nesterov | 06ba38a | 2007-05-09 02:34:15 -0700 | [diff] [blame] | 1137 | start_workqueue_thread(cwq, cpu); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1138 | break; |
| 1139 | |
| 1140 | case CPU_UP_CANCELED: |
Oleg Nesterov | 06ba38a | 2007-05-09 02:34:15 -0700 | [diff] [blame] | 1141 | start_workqueue_thread(cwq, -1); |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 1142 | case CPU_POST_DEAD: |
Oleg Nesterov | 1e35eaa2 | 2008-04-29 01:00:28 -0700 | [diff] [blame] | 1143 | cleanup_workqueue_thread(cwq); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 1144 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1145 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1146 | } |
| 1147 | |
Oleg Nesterov | 00dfcaf | 2008-04-29 01:00:27 -0700 | [diff] [blame] | 1148 | switch (action) { |
| 1149 | case CPU_UP_CANCELED: |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 1150 | case CPU_POST_DEAD: |
Rusty Russell | e7577c5 | 2009-01-01 10:12:25 +1030 | [diff] [blame] | 1151 | cpumask_clear_cpu(cpu, cpu_populated_map); |
Oleg Nesterov | 00dfcaf | 2008-04-29 01:00:27 -0700 | [diff] [blame] | 1152 | } |
| 1153 | |
Akinobu Mita | 80b5184 | 2010-05-26 14:43:32 -0700 | [diff] [blame] | 1154 | return notifier_from_errno(err); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1155 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1156 | |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1157 | #ifdef CONFIG_SMP |
Rusty Russell | 8ccad40 | 2009-01-16 15:31:15 -0800 | [diff] [blame] | 1158 | |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1159 | struct work_for_cpu { |
Andrew Morton | 6b44003e | 2009-04-09 09:50:37 -0600 | [diff] [blame] | 1160 | struct completion completion; |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1161 | long (*fn)(void *); |
| 1162 | void *arg; |
| 1163 | long ret; |
| 1164 | }; |
| 1165 | |
Andrew Morton | 6b44003e | 2009-04-09 09:50:37 -0600 | [diff] [blame] | 1166 | static int do_work_for_cpu(void *_wfc) |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1167 | { |
Andrew Morton | 6b44003e | 2009-04-09 09:50:37 -0600 | [diff] [blame] | 1168 | struct work_for_cpu *wfc = _wfc; |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1169 | wfc->ret = wfc->fn(wfc->arg); |
Andrew Morton | 6b44003e | 2009-04-09 09:50:37 -0600 | [diff] [blame] | 1170 | complete(&wfc->completion); |
| 1171 | return 0; |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1172 | } |
| 1173 | |
| 1174 | /** |
| 1175 | * work_on_cpu - run a function in user context on a particular cpu |
| 1176 | * @cpu: the cpu to run on |
| 1177 | * @fn: the function to run |
| 1178 | * @arg: the function arg |
| 1179 | * |
Rusty Russell | 31ad908 | 2009-01-16 15:31:15 -0800 | [diff] [blame] | 1180 | * This will return the value @fn returns. |
| 1181 | * 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] | 1182 | * 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] | 1183 | */ |
| 1184 | long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg) |
| 1185 | { |
Andrew Morton | 6b44003e | 2009-04-09 09:50:37 -0600 | [diff] [blame] | 1186 | struct task_struct *sub_thread; |
| 1187 | struct work_for_cpu wfc = { |
| 1188 | .completion = COMPLETION_INITIALIZER_ONSTACK(wfc.completion), |
| 1189 | .fn = fn, |
| 1190 | .arg = arg, |
| 1191 | }; |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1192 | |
Andrew Morton | 6b44003e | 2009-04-09 09:50:37 -0600 | [diff] [blame] | 1193 | sub_thread = kthread_create(do_work_for_cpu, &wfc, "work_for_cpu"); |
| 1194 | if (IS_ERR(sub_thread)) |
| 1195 | return PTR_ERR(sub_thread); |
| 1196 | kthread_bind(sub_thread, cpu); |
| 1197 | wake_up_process(sub_thread); |
| 1198 | wait_for_completion(&wfc.completion); |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1199 | return wfc.ret; |
| 1200 | } |
| 1201 | EXPORT_SYMBOL_GPL(work_on_cpu); |
| 1202 | #endif /* CONFIG_SMP */ |
| 1203 | |
Oleg Nesterov | c12920d | 2007-05-09 02:34:14 -0700 | [diff] [blame] | 1204 | void __init init_workqueues(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1205 | { |
Rusty Russell | e7577c5 | 2009-01-01 10:12:25 +1030 | [diff] [blame] | 1206 | alloc_cpumask_var(&cpu_populated_map, GFP_KERNEL); |
| 1207 | |
| 1208 | cpumask_copy(cpu_populated_map, cpu_online_mask); |
| 1209 | singlethread_cpu = cpumask_first(cpu_possible_mask); |
| 1210 | cpu_singlethread_map = cpumask_of(singlethread_cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1211 | hotcpu_notifier(workqueue_cpu_callback, 0); |
| 1212 | keventd_wq = create_workqueue("events"); |
| 1213 | BUG_ON(!keventd_wq); |
| 1214 | } |