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> |
| 12 | * Andrew Morton <andrewm@uow.edu.au> |
| 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 | /* |
Nathan Lynch | f756d5e | 2006-01-08 01:05:12 -0800 | [diff] [blame] | 38 | * The per-CPU workqueue (if single thread, we always use the first |
| 39 | * possible cpu). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | */ |
| 41 | struct cpu_workqueue_struct { |
| 42 | |
| 43 | spinlock_t lock; |
| 44 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | struct list_head worklist; |
| 46 | wait_queue_head_t more_work; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 47 | struct work_struct *current_work; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | |
| 49 | struct workqueue_struct *wq; |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 50 | struct task_struct *thread; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | |
| 52 | int run_depth; /* Detect run_workqueue() recursion depth */ |
| 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 */ |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 65 | #ifdef CONFIG_LOCKDEP |
| 66 | struct lockdep_map lockdep_map; |
| 67 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | }; |
| 69 | |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 70 | /* Serializes the accesses to the list of workqueues. */ |
| 71 | static DEFINE_SPINLOCK(workqueue_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | static LIST_HEAD(workqueues); |
| 73 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 74 | static int singlethread_cpu __read_mostly; |
Oleg Nesterov | b1f4ec1 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 75 | static cpumask_t cpu_singlethread_map __read_mostly; |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 76 | /* |
| 77 | * _cpu_down() first removes CPU from cpu_online_map, then CPU_DEAD |
| 78 | * flushes cwq->worklist. This means that flush_workqueue/wait_on_work |
| 79 | * which comes in between can't use for_each_online_cpu(). We could |
| 80 | * use cpu_possible_map, the cpumask below is more a documentation |
| 81 | * than optimization. |
| 82 | */ |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 83 | static cpumask_t cpu_populated_map __read_mostly; |
Nathan Lynch | f756d5e | 2006-01-08 01:05:12 -0800 | [diff] [blame] | 84 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | /* If it's single threaded, it isn't in the list of workqueues. */ |
| 86 | static inline int is_single_threaded(struct workqueue_struct *wq) |
| 87 | { |
Oleg Nesterov | cce1a16 | 2007-05-09 02:34:13 -0700 | [diff] [blame] | 88 | return wq->singlethread; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | } |
| 90 | |
Oleg Nesterov | b1f4ec1 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 91 | static const cpumask_t *wq_cpu_map(struct workqueue_struct *wq) |
| 92 | { |
| 93 | return is_single_threaded(wq) |
| 94 | ? &cpu_singlethread_map : &cpu_populated_map; |
| 95 | } |
| 96 | |
Oleg Nesterov | a848e3b | 2007-05-09 02:34:17 -0700 | [diff] [blame] | 97 | static |
| 98 | struct cpu_workqueue_struct *wq_per_cpu(struct workqueue_struct *wq, int cpu) |
| 99 | { |
| 100 | if (unlikely(is_single_threaded(wq))) |
| 101 | cpu = singlethread_cpu; |
| 102 | return per_cpu_ptr(wq->cpu_wq, cpu); |
| 103 | } |
| 104 | |
David Howells | 4594bf1 | 2006-12-07 11:33:26 +0000 | [diff] [blame] | 105 | /* |
| 106 | * Set the workqueue on which a work item is to be run |
| 107 | * - Must *only* be called if the pending flag is set |
| 108 | */ |
Oleg Nesterov | ed7c0fe | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 109 | static inline void set_wq_data(struct work_struct *work, |
| 110 | struct cpu_workqueue_struct *cwq) |
David Howells | 365970a | 2006-11-22 14:54:49 +0000 | [diff] [blame] | 111 | { |
David Howells | 4594bf1 | 2006-12-07 11:33:26 +0000 | [diff] [blame] | 112 | unsigned long new; |
David Howells | 365970a | 2006-11-22 14:54:49 +0000 | [diff] [blame] | 113 | |
David Howells | 4594bf1 | 2006-12-07 11:33:26 +0000 | [diff] [blame] | 114 | BUG_ON(!work_pending(work)); |
| 115 | |
Oleg Nesterov | ed7c0fe | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 116 | new = (unsigned long) cwq | (1UL << WORK_STRUCT_PENDING); |
Linus Torvalds | a08727b | 2006-12-16 09:53:50 -0800 | [diff] [blame] | 117 | new |= WORK_STRUCT_FLAG_MASK & *work_data_bits(work); |
| 118 | atomic_long_set(&work->data, new); |
David Howells | 365970a | 2006-11-22 14:54:49 +0000 | [diff] [blame] | 119 | } |
| 120 | |
Oleg Nesterov | ed7c0fe | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 121 | static inline |
| 122 | struct cpu_workqueue_struct *get_wq_data(struct work_struct *work) |
David Howells | 365970a | 2006-11-22 14:54:49 +0000 | [diff] [blame] | 123 | { |
Linus Torvalds | a08727b | 2006-12-16 09:53:50 -0800 | [diff] [blame] | 124 | return (void *) (atomic_long_read(&work->data) & WORK_STRUCT_WQ_DATA_MASK); |
David Howells | 365970a | 2006-11-22 14:54:49 +0000 | [diff] [blame] | 125 | } |
| 126 | |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 127 | static void insert_work(struct cpu_workqueue_struct *cwq, |
Oleg Nesterov | 1a4d9b0 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 128 | struct work_struct *work, struct list_head *head) |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 129 | { |
| 130 | set_wq_data(work, cwq); |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 131 | /* |
| 132 | * Ensure that we get the right work->data if we see the |
| 133 | * result of list_add() below, see try_to_grab_pending(). |
| 134 | */ |
| 135 | smp_wmb(); |
Oleg Nesterov | 1a4d9b0 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 136 | list_add_tail(&work->entry, head); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 137 | wake_up(&cwq->more_work); |
| 138 | } |
| 139 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | static void __queue_work(struct cpu_workqueue_struct *cwq, |
| 141 | struct work_struct *work) |
| 142 | { |
| 143 | unsigned long flags; |
| 144 | |
| 145 | spin_lock_irqsave(&cwq->lock, flags); |
Oleg Nesterov | 1a4d9b0 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 146 | insert_work(cwq, work, &cwq->worklist); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | spin_unlock_irqrestore(&cwq->lock, flags); |
| 148 | } |
| 149 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 150 | /** |
| 151 | * queue_work - queue work on a workqueue |
| 152 | * @wq: workqueue to use |
| 153 | * @work: work to queue |
| 154 | * |
Alan Stern | 057647f | 2006-10-28 10:38:58 -0700 | [diff] [blame] | 155 | * Returns 0 if @work was already on a queue, non-zero otherwise. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | * |
Oleg Nesterov | 00dfcaf | 2008-04-29 01:00:27 -0700 | [diff] [blame] | 157 | * We queue the work to the CPU on which it was submitted, but if the CPU dies |
| 158 | * it can be processed by another CPU. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 159 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 160 | int queue_work(struct workqueue_struct *wq, struct work_struct *work) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | { |
Oleg Nesterov | a848e3b | 2007-05-09 02:34:17 -0700 | [diff] [blame] | 162 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | |
Linus Torvalds | a08727b | 2006-12-16 09:53:50 -0800 | [diff] [blame] | 164 | if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | BUG_ON(!list_empty(&work->entry)); |
Oleg Nesterov | a848e3b | 2007-05-09 02:34:17 -0700 | [diff] [blame] | 166 | __queue_work(wq_per_cpu(wq, get_cpu()), work); |
| 167 | put_cpu(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | ret = 1; |
| 169 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | return ret; |
| 171 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 172 | EXPORT_SYMBOL_GPL(queue_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | |
Zhang Rui | c1a220e | 2008-07-23 21:28:39 -0700 | [diff] [blame] | 174 | /** |
| 175 | * queue_work_on - queue work on specific cpu |
| 176 | * @cpu: CPU number to execute work on |
| 177 | * @wq: workqueue to use |
| 178 | * @work: work to queue |
| 179 | * |
| 180 | * Returns 0 if @work was already on a queue, non-zero otherwise. |
| 181 | * |
| 182 | * We queue the work to a specific CPU, the caller must ensure it |
| 183 | * can't go away. |
| 184 | */ |
| 185 | int |
| 186 | queue_work_on(int cpu, struct workqueue_struct *wq, struct work_struct *work) |
| 187 | { |
| 188 | int ret = 0; |
| 189 | |
| 190 | if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) { |
| 191 | BUG_ON(!list_empty(&work->entry)); |
| 192 | __queue_work(wq_per_cpu(wq, cpu), work); |
| 193 | ret = 1; |
| 194 | } |
| 195 | return ret; |
| 196 | } |
| 197 | EXPORT_SYMBOL_GPL(queue_work_on); |
| 198 | |
Li Zefan | 6d141c3 | 2008-02-08 04:21:09 -0800 | [diff] [blame] | 199 | static void delayed_work_timer_fn(unsigned long __data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | { |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 201 | struct delayed_work *dwork = (struct delayed_work *)__data; |
Oleg Nesterov | ed7c0fe | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 202 | struct cpu_workqueue_struct *cwq = get_wq_data(&dwork->work); |
| 203 | struct workqueue_struct *wq = cwq->wq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | |
Oleg Nesterov | a848e3b | 2007-05-09 02:34:17 -0700 | [diff] [blame] | 205 | __queue_work(wq_per_cpu(wq, smp_processor_id()), &dwork->work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 206 | } |
| 207 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 208 | /** |
| 209 | * queue_delayed_work - queue work on a workqueue after delay |
| 210 | * @wq: workqueue to use |
Randy Dunlap | af9997e | 2006-12-22 01:06:52 -0800 | [diff] [blame] | 211 | * @dwork: delayable work to queue |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 212 | * @delay: number of jiffies to wait before queueing |
| 213 | * |
Alan Stern | 057647f | 2006-10-28 10:38:58 -0700 | [diff] [blame] | 214 | * 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] | 215 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 216 | int queue_delayed_work(struct workqueue_struct *wq, |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 217 | struct delayed_work *dwork, unsigned long delay) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 218 | { |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 219 | if (delay == 0) |
Oleg Nesterov | 63bc036 | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 220 | return queue_work(wq, &dwork->work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | |
Oleg Nesterov | 63bc036 | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 222 | return queue_delayed_work_on(-1, wq, dwork, delay); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 224 | EXPORT_SYMBOL_GPL(queue_delayed_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 226 | /** |
| 227 | * queue_delayed_work_on - queue work on specific CPU after delay |
| 228 | * @cpu: CPU number to execute work on |
| 229 | * @wq: workqueue to use |
Randy Dunlap | af9997e | 2006-12-22 01:06:52 -0800 | [diff] [blame] | 230 | * @dwork: work to queue |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 231 | * @delay: number of jiffies to wait before queueing |
| 232 | * |
Alan Stern | 057647f | 2006-10-28 10:38:58 -0700 | [diff] [blame] | 233 | * 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] | 234 | */ |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 235 | int queue_delayed_work_on(int cpu, struct workqueue_struct *wq, |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 236 | struct delayed_work *dwork, unsigned long delay) |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 237 | { |
| 238 | int ret = 0; |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 239 | struct timer_list *timer = &dwork->timer; |
| 240 | struct work_struct *work = &dwork->work; |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 241 | |
Linus Torvalds | a08727b | 2006-12-16 09:53:50 -0800 | [diff] [blame] | 242 | if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) { |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 243 | BUG_ON(timer_pending(timer)); |
| 244 | BUG_ON(!list_empty(&work->entry)); |
| 245 | |
Andrew Liu | 8a3e77c | 2008-05-01 04:35:14 -0700 | [diff] [blame] | 246 | timer_stats_timer_set_start_info(&dwork->timer); |
| 247 | |
Oleg Nesterov | ed7c0fe | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 248 | /* This stores cwq for the moment, for the timer_fn */ |
Oleg Nesterov | a848e3b | 2007-05-09 02:34:17 -0700 | [diff] [blame] | 249 | set_wq_data(work, wq_per_cpu(wq, raw_smp_processor_id())); |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 250 | timer->expires = jiffies + delay; |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 251 | timer->data = (unsigned long)dwork; |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 252 | timer->function = delayed_work_timer_fn; |
Oleg Nesterov | 63bc036 | 2007-05-09 02:34:16 -0700 | [diff] [blame] | 253 | |
| 254 | if (unlikely(cpu >= 0)) |
| 255 | add_timer_on(timer, cpu); |
| 256 | else |
| 257 | add_timer(timer); |
Venkatesh Pallipadi | 7a6bc1c | 2006-06-28 13:50:33 -0700 | [diff] [blame] | 258 | ret = 1; |
| 259 | } |
| 260 | return ret; |
| 261 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 262 | EXPORT_SYMBOL_GPL(queue_delayed_work_on); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 263 | |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 264 | static void run_workqueue(struct cpu_workqueue_struct *cwq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | { |
Oleg Nesterov | f293ea9 | 2007-05-09 02:34:10 -0700 | [diff] [blame] | 266 | spin_lock_irq(&cwq->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | cwq->run_depth++; |
| 268 | if (cwq->run_depth > 3) { |
| 269 | /* morton gets to eat his hat */ |
| 270 | printk("%s: recursion depth exceeded: %d\n", |
Harvey Harrison | af1f16d | 2008-04-30 00:55:08 -0700 | [diff] [blame] | 271 | __func__, cwq->run_depth); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | dump_stack(); |
| 273 | } |
| 274 | while (!list_empty(&cwq->worklist)) { |
| 275 | struct work_struct *work = list_entry(cwq->worklist.next, |
| 276 | struct work_struct, entry); |
David Howells | 6bb49e5 | 2006-11-22 14:54:45 +0000 | [diff] [blame] | 277 | work_func_t f = work->func; |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 278 | #ifdef CONFIG_LOCKDEP |
| 279 | /* |
| 280 | * It is permissible to free the struct work_struct |
| 281 | * from inside the function that is called from it, |
| 282 | * this we need to take into account for lockdep too. |
| 283 | * To avoid bogus "held lock freed" warnings as well |
| 284 | * as problems when looking into work->lockdep_map, |
| 285 | * make a copy and use that here. |
| 286 | */ |
| 287 | struct lockdep_map lockdep_map = work->lockdep_map; |
| 288 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 289 | |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 290 | cwq->current_work = work; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | list_del_init(cwq->worklist.next); |
Oleg Nesterov | f293ea9 | 2007-05-09 02:34:10 -0700 | [diff] [blame] | 292 | spin_unlock_irq(&cwq->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 293 | |
David Howells | 365970a | 2006-11-22 14:54:49 +0000 | [diff] [blame] | 294 | BUG_ON(get_wq_data(work) != cwq); |
Oleg Nesterov | 23b2e59 | 2007-05-09 02:34:19 -0700 | [diff] [blame] | 295 | work_clear_pending(work); |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 296 | lock_acquire(&cwq->wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_); |
| 297 | lock_acquire(&lockdep_map, 0, 0, 0, 2, _THIS_IP_); |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 298 | f(work); |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 299 | lock_release(&lockdep_map, 1, _THIS_IP_); |
| 300 | lock_release(&cwq->wq->lockdep_map, 1, _THIS_IP_); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | |
Peter Zijlstra | d5abe66 | 2006-12-06 20:37:26 -0800 | [diff] [blame] | 302 | if (unlikely(in_atomic() || lockdep_depth(current) > 0)) { |
| 303 | printk(KERN_ERR "BUG: workqueue leaked lock or atomic: " |
| 304 | "%s/0x%08x/%d\n", |
| 305 | current->comm, preempt_count(), |
Pavel Emelyanov | ba25f9d | 2007-10-18 23:40:40 -0700 | [diff] [blame] | 306 | task_pid_nr(current)); |
Peter Zijlstra | d5abe66 | 2006-12-06 20:37:26 -0800 | [diff] [blame] | 307 | printk(KERN_ERR " last function: "); |
| 308 | print_symbol("%s\n", (unsigned long)f); |
| 309 | debug_show_held_locks(current); |
| 310 | dump_stack(); |
| 311 | } |
| 312 | |
Oleg Nesterov | f293ea9 | 2007-05-09 02:34:10 -0700 | [diff] [blame] | 313 | spin_lock_irq(&cwq->lock); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 314 | cwq->current_work = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | } |
| 316 | cwq->run_depth--; |
Oleg Nesterov | f293ea9 | 2007-05-09 02:34:10 -0700 | [diff] [blame] | 317 | spin_unlock_irq(&cwq->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | } |
| 319 | |
| 320 | static int worker_thread(void *__cwq) |
| 321 | { |
| 322 | struct cpu_workqueue_struct *cwq = __cwq; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 323 | DEFINE_WAIT(wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 324 | |
Rafael J. Wysocki | 8314418 | 2007-07-17 04:03:35 -0700 | [diff] [blame] | 325 | if (cwq->wq->freezeable) |
| 326 | set_freezable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 327 | |
| 328 | set_user_nice(current, -5); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 330 | for (;;) { |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 331 | prepare_to_wait(&cwq->more_work, &wait, TASK_INTERRUPTIBLE); |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 332 | if (!freezing(current) && |
| 333 | !kthread_should_stop() && |
| 334 | list_empty(&cwq->worklist)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | schedule(); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 336 | finish_wait(&cwq->more_work, &wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | |
Oleg Nesterov | 85f4186 | 2007-05-09 02:34:20 -0700 | [diff] [blame] | 338 | try_to_freeze(); |
| 339 | |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 340 | if (kthread_should_stop()) |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 341 | break; |
| 342 | |
| 343 | run_workqueue(cwq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 344 | } |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 345 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 346 | return 0; |
| 347 | } |
| 348 | |
Oleg Nesterov | fc2e4d7 | 2007-05-09 02:33:51 -0700 | [diff] [blame] | 349 | struct wq_barrier { |
| 350 | struct work_struct work; |
| 351 | struct completion done; |
| 352 | }; |
| 353 | |
| 354 | static void wq_barrier_func(struct work_struct *work) |
| 355 | { |
| 356 | struct wq_barrier *barr = container_of(work, struct wq_barrier, work); |
| 357 | complete(&barr->done); |
| 358 | } |
| 359 | |
Oleg Nesterov | 83c2252 | 2007-05-09 02:33:54 -0700 | [diff] [blame] | 360 | static void insert_wq_barrier(struct cpu_workqueue_struct *cwq, |
Oleg Nesterov | 1a4d9b0 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 361 | struct wq_barrier *barr, struct list_head *head) |
Oleg Nesterov | fc2e4d7 | 2007-05-09 02:33:51 -0700 | [diff] [blame] | 362 | { |
| 363 | INIT_WORK(&barr->work, wq_barrier_func); |
| 364 | __set_bit(WORK_STRUCT_PENDING, work_data_bits(&barr->work)); |
| 365 | |
| 366 | init_completion(&barr->done); |
Oleg Nesterov | 83c2252 | 2007-05-09 02:33:54 -0700 | [diff] [blame] | 367 | |
Oleg Nesterov | 1a4d9b0 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 368 | insert_work(cwq, &barr->work, head); |
Oleg Nesterov | fc2e4d7 | 2007-05-09 02:33:51 -0700 | [diff] [blame] | 369 | } |
| 370 | |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 371 | static int flush_cpu_workqueue(struct cpu_workqueue_struct *cwq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | { |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 373 | int active; |
| 374 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | if (cwq->thread == current) { |
| 376 | /* |
| 377 | * Probably keventd trying to flush its own queue. So simply run |
| 378 | * it by hand rather than deadlocking. |
| 379 | */ |
| 380 | run_workqueue(cwq); |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 381 | active = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 382 | } else { |
Oleg Nesterov | fc2e4d7 | 2007-05-09 02:33:51 -0700 | [diff] [blame] | 383 | struct wq_barrier barr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 384 | |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 385 | active = 0; |
Oleg Nesterov | 83c2252 | 2007-05-09 02:33:54 -0700 | [diff] [blame] | 386 | spin_lock_irq(&cwq->lock); |
| 387 | if (!list_empty(&cwq->worklist) || cwq->current_work != NULL) { |
Oleg Nesterov | 1a4d9b0 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 388 | insert_wq_barrier(cwq, &barr, &cwq->worklist); |
Oleg Nesterov | 83c2252 | 2007-05-09 02:33:54 -0700 | [diff] [blame] | 389 | active = 1; |
| 390 | } |
| 391 | spin_unlock_irq(&cwq->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | |
Oleg Nesterov | d721304 | 2007-05-09 02:34:07 -0700 | [diff] [blame] | 393 | if (active) |
Oleg Nesterov | 83c2252 | 2007-05-09 02:33:54 -0700 | [diff] [blame] | 394 | wait_for_completion(&barr.done); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 395 | } |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 396 | |
| 397 | return active; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 398 | } |
| 399 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 400 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 401 | * flush_workqueue - ensure that any scheduled work has run to completion. |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 402 | * @wq: workqueue to flush |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 403 | * |
| 404 | * Forces execution of the workqueue and blocks until its completion. |
| 405 | * This is typically used in driver shutdown handlers. |
| 406 | * |
Oleg Nesterov | fc2e4d7 | 2007-05-09 02:33:51 -0700 | [diff] [blame] | 407 | * We sleep until all works which were queued on entry have been handled, |
| 408 | * but we are not livelocked by new incoming ones. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | * |
| 410 | * This function used to run the workqueues itself. Now we just wait for the |
| 411 | * helper threads to do it. |
| 412 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 413 | void flush_workqueue(struct workqueue_struct *wq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 414 | { |
Oleg Nesterov | b1f4ec1 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 415 | const cpumask_t *cpu_map = wq_cpu_map(wq); |
Oleg Nesterov | cce1a16 | 2007-05-09 02:34:13 -0700 | [diff] [blame] | 416 | int cpu; |
Oleg Nesterov | b1f4ec1 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 417 | |
Oleg Nesterov | f293ea9 | 2007-05-09 02:34:10 -0700 | [diff] [blame] | 418 | might_sleep(); |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 419 | lock_acquire(&wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_); |
| 420 | lock_release(&wq->lockdep_map, 1, _THIS_IP_); |
Mike Travis | 363ab6f | 2008-05-12 21:21:13 +0200 | [diff] [blame] | 421 | for_each_cpu_mask_nr(cpu, *cpu_map) |
Oleg Nesterov | b1f4ec1 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 422 | flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 424 | EXPORT_SYMBOL_GPL(flush_workqueue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 425 | |
Oleg Nesterov | db70089 | 2008-07-25 01:47:49 -0700 | [diff] [blame] | 426 | /** |
| 427 | * flush_work - block until a work_struct's callback has terminated |
| 428 | * @work: the work which is to be flushed |
| 429 | * |
Oleg Nesterov | a67da70 | 2008-07-25 01:47:52 -0700 | [diff] [blame^] | 430 | * Returns false if @work has already terminated. |
| 431 | * |
Oleg Nesterov | db70089 | 2008-07-25 01:47:49 -0700 | [diff] [blame] | 432 | * It is expected that, prior to calling flush_work(), the caller has |
| 433 | * arranged for the work to not be requeued, otherwise it doesn't make |
| 434 | * sense to use this function. |
| 435 | */ |
| 436 | int flush_work(struct work_struct *work) |
| 437 | { |
| 438 | struct cpu_workqueue_struct *cwq; |
| 439 | struct list_head *prev; |
| 440 | struct wq_barrier barr; |
| 441 | |
| 442 | might_sleep(); |
| 443 | cwq = get_wq_data(work); |
| 444 | if (!cwq) |
| 445 | return 0; |
| 446 | |
Oleg Nesterov | a67da70 | 2008-07-25 01:47:52 -0700 | [diff] [blame^] | 447 | lock_acquire(&cwq->wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_); |
| 448 | lock_release(&cwq->wq->lockdep_map, 1, _THIS_IP_); |
| 449 | |
Oleg Nesterov | db70089 | 2008-07-25 01:47:49 -0700 | [diff] [blame] | 450 | prev = NULL; |
| 451 | spin_lock_irq(&cwq->lock); |
| 452 | if (!list_empty(&work->entry)) { |
| 453 | /* |
| 454 | * See the comment near try_to_grab_pending()->smp_rmb(). |
| 455 | * If it was re-queued under us we are not going to wait. |
| 456 | */ |
| 457 | smp_rmb(); |
| 458 | if (unlikely(cwq != get_wq_data(work))) |
| 459 | goto out; |
| 460 | prev = &work->entry; |
| 461 | } else { |
| 462 | if (cwq->current_work != work) |
| 463 | goto out; |
| 464 | prev = &cwq->worklist; |
| 465 | } |
| 466 | insert_wq_barrier(cwq, &barr, prev->next); |
| 467 | out: |
| 468 | spin_unlock_irq(&cwq->lock); |
| 469 | if (!prev) |
| 470 | return 0; |
| 471 | |
| 472 | wait_for_completion(&barr.done); |
| 473 | return 1; |
| 474 | } |
| 475 | EXPORT_SYMBOL_GPL(flush_work); |
| 476 | |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 477 | /* |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 478 | * Upon a successful return (>= 0), the caller "owns" WORK_STRUCT_PENDING bit, |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 479 | * so this work can't be re-armed in any way. |
| 480 | */ |
| 481 | static int try_to_grab_pending(struct work_struct *work) |
| 482 | { |
| 483 | struct cpu_workqueue_struct *cwq; |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 484 | int ret = -1; |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 485 | |
| 486 | if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 487 | return 0; |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 488 | |
| 489 | /* |
| 490 | * The queueing is in progress, or it is already queued. Try to |
| 491 | * steal it from ->worklist without clearing WORK_STRUCT_PENDING. |
| 492 | */ |
| 493 | |
| 494 | cwq = get_wq_data(work); |
| 495 | if (!cwq) |
| 496 | return ret; |
| 497 | |
| 498 | spin_lock_irq(&cwq->lock); |
| 499 | if (!list_empty(&work->entry)) { |
| 500 | /* |
| 501 | * This work is queued, but perhaps we locked the wrong cwq. |
| 502 | * In that case we must see the new value after rmb(), see |
| 503 | * insert_work()->wmb(). |
| 504 | */ |
| 505 | smp_rmb(); |
| 506 | if (cwq == get_wq_data(work)) { |
| 507 | list_del_init(&work->entry); |
| 508 | ret = 1; |
| 509 | } |
| 510 | } |
| 511 | spin_unlock_irq(&cwq->lock); |
| 512 | |
| 513 | return ret; |
| 514 | } |
| 515 | |
| 516 | static void wait_on_cpu_work(struct cpu_workqueue_struct *cwq, |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 517 | struct work_struct *work) |
| 518 | { |
| 519 | struct wq_barrier barr; |
| 520 | int running = 0; |
| 521 | |
| 522 | spin_lock_irq(&cwq->lock); |
| 523 | if (unlikely(cwq->current_work == work)) { |
Oleg Nesterov | 1a4d9b0 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 524 | insert_wq_barrier(cwq, &barr, cwq->worklist.next); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 525 | running = 1; |
| 526 | } |
| 527 | spin_unlock_irq(&cwq->lock); |
| 528 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 529 | if (unlikely(running)) |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 530 | wait_for_completion(&barr.done); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 531 | } |
| 532 | |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 533 | static void wait_on_work(struct work_struct *work) |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 534 | { |
| 535 | struct cpu_workqueue_struct *cwq; |
Oleg Nesterov | 28e53bd | 2007-05-09 02:34:22 -0700 | [diff] [blame] | 536 | struct workqueue_struct *wq; |
| 537 | const cpumask_t *cpu_map; |
Oleg Nesterov | b1f4ec1 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 538 | int cpu; |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 539 | |
Oleg Nesterov | f293ea9 | 2007-05-09 02:34:10 -0700 | [diff] [blame] | 540 | might_sleep(); |
| 541 | |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 542 | lock_acquire(&work->lockdep_map, 0, 0, 0, 2, _THIS_IP_); |
| 543 | lock_release(&work->lockdep_map, 1, _THIS_IP_); |
| 544 | |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 545 | cwq = get_wq_data(work); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 546 | if (!cwq) |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 547 | return; |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 548 | |
Oleg Nesterov | 28e53bd | 2007-05-09 02:34:22 -0700 | [diff] [blame] | 549 | wq = cwq->wq; |
| 550 | cpu_map = wq_cpu_map(wq); |
| 551 | |
Mike Travis | 363ab6f | 2008-05-12 21:21:13 +0200 | [diff] [blame] | 552 | for_each_cpu_mask_nr(cpu, *cpu_map) |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 553 | wait_on_cpu_work(per_cpu_ptr(wq->cpu_wq, cpu), work); |
| 554 | } |
| 555 | |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 556 | static int __cancel_work_timer(struct work_struct *work, |
| 557 | struct timer_list* timer) |
| 558 | { |
| 559 | int ret; |
| 560 | |
| 561 | do { |
| 562 | ret = (timer && likely(del_timer(timer))); |
| 563 | if (!ret) |
| 564 | ret = try_to_grab_pending(work); |
| 565 | wait_on_work(work); |
| 566 | } while (unlikely(ret < 0)); |
| 567 | |
| 568 | work_clear_pending(work); |
| 569 | return ret; |
| 570 | } |
| 571 | |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 572 | /** |
| 573 | * cancel_work_sync - block until a work_struct's callback has terminated |
| 574 | * @work: the work which is to be flushed |
| 575 | * |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 576 | * Returns true if @work was pending. |
| 577 | * |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 578 | * cancel_work_sync() will cancel the work if it is queued. If the work's |
| 579 | * callback appears to be running, cancel_work_sync() will block until it |
| 580 | * has completed. |
| 581 | * |
| 582 | * It is possible to use this function if the work re-queues itself. It can |
| 583 | * cancel the work even if it migrates to another workqueue, however in that |
| 584 | * case it only guarantees that work->func() has completed on the last queued |
| 585 | * workqueue. |
| 586 | * |
| 587 | * cancel_work_sync(&delayed_work->work) should be used only if ->timer is not |
| 588 | * pending, otherwise it goes into a busy-wait loop until the timer expires. |
| 589 | * |
| 590 | * The caller must ensure that workqueue_struct on which this work was last |
| 591 | * queued can't be destroyed before this function returns. |
| 592 | */ |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 593 | int cancel_work_sync(struct work_struct *work) |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 594 | { |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 595 | return __cancel_work_timer(work, NULL); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 596 | } |
Oleg Nesterov | 28e53bd | 2007-05-09 02:34:22 -0700 | [diff] [blame] | 597 | EXPORT_SYMBOL_GPL(cancel_work_sync); |
Oleg Nesterov | b89deed | 2007-05-09 02:33:52 -0700 | [diff] [blame] | 598 | |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 599 | /** |
Oleg Nesterov | f5a421a | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 600 | * cancel_delayed_work_sync - reliably kill off a delayed work. |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 601 | * @dwork: the delayed work struct |
| 602 | * |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 603 | * Returns true if @dwork was pending. |
| 604 | * |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 605 | * It is possible to use this function if @dwork rearms itself via queue_work() |
| 606 | * or queue_delayed_work(). See also the comment for cancel_work_sync(). |
| 607 | */ |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 608 | int cancel_delayed_work_sync(struct delayed_work *dwork) |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 609 | { |
Oleg Nesterov | 1f1f642 | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 610 | return __cancel_work_timer(&dwork->work, &dwork->timer); |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 611 | } |
Oleg Nesterov | f5a421a | 2007-07-15 23:41:44 -0700 | [diff] [blame] | 612 | EXPORT_SYMBOL(cancel_delayed_work_sync); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 613 | |
Oleg Nesterov | 6e84d64 | 2007-05-09 02:34:46 -0700 | [diff] [blame] | 614 | static struct workqueue_struct *keventd_wq __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 615 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 616 | /** |
| 617 | * schedule_work - put work task in global workqueue |
| 618 | * @work: job to be done |
| 619 | * |
| 620 | * This puts a job in the kernel-global workqueue. |
| 621 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 622 | int schedule_work(struct work_struct *work) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 623 | { |
| 624 | return queue_work(keventd_wq, work); |
| 625 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 626 | EXPORT_SYMBOL(schedule_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | |
Zhang Rui | c1a220e | 2008-07-23 21:28:39 -0700 | [diff] [blame] | 628 | /* |
| 629 | * schedule_work_on - put work task on a specific cpu |
| 630 | * @cpu: cpu to put the work task on |
| 631 | * @work: job to be done |
| 632 | * |
| 633 | * This puts a job on a specific cpu |
| 634 | */ |
| 635 | int schedule_work_on(int cpu, struct work_struct *work) |
| 636 | { |
| 637 | return queue_work_on(cpu, keventd_wq, work); |
| 638 | } |
| 639 | EXPORT_SYMBOL(schedule_work_on); |
| 640 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 641 | /** |
| 642 | * schedule_delayed_work - put work task in global workqueue after delay |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 643 | * @dwork: job to be done |
| 644 | * @delay: number of jiffies to wait or 0 for immediate execution |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 645 | * |
| 646 | * After waiting for a given time this puts a job in the kernel-global |
| 647 | * workqueue. |
| 648 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 649 | int schedule_delayed_work(struct delayed_work *dwork, |
Ingo Molnar | 82f67cd | 2007-02-16 01:28:13 -0800 | [diff] [blame] | 650 | unsigned long delay) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 651 | { |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 652 | return queue_delayed_work(keventd_wq, dwork, delay); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 653 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 654 | EXPORT_SYMBOL(schedule_delayed_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 655 | |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 656 | /** |
| 657 | * schedule_delayed_work_on - queue work in global workqueue on CPU after delay |
| 658 | * @cpu: cpu to use |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 659 | * @dwork: job to be done |
Rolf Eike Beer | 0fcb78c | 2006-07-30 03:03:42 -0700 | [diff] [blame] | 660 | * @delay: number of jiffies to wait |
| 661 | * |
| 662 | * After waiting for a given time this puts a job in the kernel-global |
| 663 | * workqueue on the specified CPU. |
| 664 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 665 | int schedule_delayed_work_on(int cpu, |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 666 | struct delayed_work *dwork, unsigned long delay) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 667 | { |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 668 | return queue_delayed_work_on(cpu, keventd_wq, dwork, delay); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 670 | EXPORT_SYMBOL(schedule_delayed_work_on); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 671 | |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 672 | /** |
| 673 | * schedule_on_each_cpu - call a function on each online CPU from keventd |
| 674 | * @func: the function to call |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 675 | * |
| 676 | * Returns zero on success. |
| 677 | * Returns -ve errno on failure. |
| 678 | * |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 679 | * schedule_on_each_cpu() is very slow. |
| 680 | */ |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 681 | int schedule_on_each_cpu(work_func_t func) |
Christoph Lameter | 15316ba | 2006-01-08 01:00:43 -0800 | [diff] [blame] | 682 | { |
| 683 | int cpu; |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 684 | struct work_struct *works; |
Christoph Lameter | 15316ba | 2006-01-08 01:00:43 -0800 | [diff] [blame] | 685 | |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 686 | works = alloc_percpu(struct work_struct); |
| 687 | if (!works) |
Christoph Lameter | 15316ba | 2006-01-08 01:00:43 -0800 | [diff] [blame] | 688 | return -ENOMEM; |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 689 | |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 690 | get_online_cpus(); |
Christoph Lameter | 15316ba | 2006-01-08 01:00:43 -0800 | [diff] [blame] | 691 | for_each_online_cpu(cpu) { |
Ingo Molnar | 9bfb183 | 2006-12-18 20:05:09 +0100 | [diff] [blame] | 692 | struct work_struct *work = per_cpu_ptr(works, cpu); |
| 693 | |
| 694 | INIT_WORK(work, func); |
| 695 | set_bit(WORK_STRUCT_PENDING, work_data_bits(work)); |
| 696 | __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu), work); |
Christoph Lameter | 15316ba | 2006-01-08 01:00:43 -0800 | [diff] [blame] | 697 | } |
Oleg Nesterov | 8616a89 | 2008-07-25 01:47:49 -0700 | [diff] [blame] | 698 | for_each_online_cpu(cpu) |
| 699 | flush_work(per_cpu_ptr(works, cpu)); |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 700 | put_online_cpus(); |
Andrew Morton | b613677 | 2006-06-25 05:47:49 -0700 | [diff] [blame] | 701 | free_percpu(works); |
Christoph Lameter | 15316ba | 2006-01-08 01:00:43 -0800 | [diff] [blame] | 702 | return 0; |
| 703 | } |
| 704 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 705 | void flush_scheduled_work(void) |
| 706 | { |
| 707 | flush_workqueue(keventd_wq); |
| 708 | } |
Dave Jones | ae90dd5 | 2006-06-30 01:40:45 -0400 | [diff] [blame] | 709 | EXPORT_SYMBOL(flush_scheduled_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 710 | |
| 711 | /** |
James Bottomley | 1fa44ec | 2006-02-23 12:43:43 -0600 | [diff] [blame] | 712 | * execute_in_process_context - reliably execute the routine with user context |
| 713 | * @fn: the function to execute |
James Bottomley | 1fa44ec | 2006-02-23 12:43:43 -0600 | [diff] [blame] | 714 | * @ew: guaranteed storage for the execute work structure (must |
| 715 | * be available when the work executes) |
| 716 | * |
| 717 | * Executes the function immediately if process context is available, |
| 718 | * otherwise schedules the function for delayed execution. |
| 719 | * |
| 720 | * Returns: 0 - function was executed |
| 721 | * 1 - function was scheduled for execution |
| 722 | */ |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 723 | 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] | 724 | { |
| 725 | if (!in_interrupt()) { |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 726 | fn(&ew->work); |
James Bottomley | 1fa44ec | 2006-02-23 12:43:43 -0600 | [diff] [blame] | 727 | return 0; |
| 728 | } |
| 729 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 730 | INIT_WORK(&ew->work, fn); |
James Bottomley | 1fa44ec | 2006-02-23 12:43:43 -0600 | [diff] [blame] | 731 | schedule_work(&ew->work); |
| 732 | |
| 733 | return 1; |
| 734 | } |
| 735 | EXPORT_SYMBOL_GPL(execute_in_process_context); |
| 736 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 737 | int keventd_up(void) |
| 738 | { |
| 739 | return keventd_wq != NULL; |
| 740 | } |
| 741 | |
| 742 | int current_is_keventd(void) |
| 743 | { |
| 744 | struct cpu_workqueue_struct *cwq; |
Hugh Dickins | d243769 | 2007-08-27 16:06:19 +0100 | [diff] [blame] | 745 | int cpu = raw_smp_processor_id(); /* preempt-safe: keventd is per-cpu */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 746 | int ret = 0; |
| 747 | |
| 748 | BUG_ON(!keventd_wq); |
| 749 | |
Christoph Lameter | 89ada67 | 2005-10-30 15:01:59 -0800 | [diff] [blame] | 750 | cwq = per_cpu_ptr(keventd_wq->cpu_wq, cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 751 | if (current == cwq->thread) |
| 752 | ret = 1; |
| 753 | |
| 754 | return ret; |
| 755 | |
| 756 | } |
| 757 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 758 | static struct cpu_workqueue_struct * |
| 759 | init_cpu_workqueue(struct workqueue_struct *wq, int cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 760 | { |
Christoph Lameter | 89ada67 | 2005-10-30 15:01:59 -0800 | [diff] [blame] | 761 | struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 762 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 763 | cwq->wq = wq; |
| 764 | spin_lock_init(&cwq->lock); |
| 765 | INIT_LIST_HEAD(&cwq->worklist); |
| 766 | init_waitqueue_head(&cwq->more_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 767 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 768 | return cwq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 769 | } |
| 770 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 771 | static int create_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 772 | { |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 773 | struct workqueue_struct *wq = cwq->wq; |
| 774 | const char *fmt = is_single_threaded(wq) ? "%s" : "%s/%d"; |
| 775 | struct task_struct *p; |
| 776 | |
| 777 | p = kthread_create(worker_thread, cwq, fmt, wq->name, cpu); |
| 778 | /* |
| 779 | * Nobody can add the work_struct to this cwq, |
| 780 | * if (caller is __create_workqueue) |
| 781 | * nobody should see this wq |
| 782 | * else // caller is CPU_UP_PREPARE |
| 783 | * cpu is not on cpu_online_map |
| 784 | * so we can abort safely. |
| 785 | */ |
| 786 | if (IS_ERR(p)) |
| 787 | return PTR_ERR(p); |
| 788 | |
| 789 | cwq->thread = p; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 790 | |
| 791 | return 0; |
| 792 | } |
| 793 | |
Oleg Nesterov | 06ba38a | 2007-05-09 02:34:15 -0700 | [diff] [blame] | 794 | static void start_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu) |
| 795 | { |
| 796 | struct task_struct *p = cwq->thread; |
| 797 | |
| 798 | if (p != NULL) { |
| 799 | if (cpu >= 0) |
| 800 | kthread_bind(p, cpu); |
| 801 | wake_up_process(p); |
| 802 | } |
| 803 | } |
| 804 | |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 805 | struct workqueue_struct *__create_workqueue_key(const char *name, |
| 806 | int singlethread, |
| 807 | int freezeable, |
Johannes Berg | eb13ba8 | 2008-01-16 09:51:58 +0100 | [diff] [blame] | 808 | struct lock_class_key *key, |
| 809 | const char *lock_name) |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 810 | { |
| 811 | struct workqueue_struct *wq; |
| 812 | struct cpu_workqueue_struct *cwq; |
| 813 | int err = 0, cpu; |
| 814 | |
| 815 | wq = kzalloc(sizeof(*wq), GFP_KERNEL); |
| 816 | if (!wq) |
| 817 | return NULL; |
| 818 | |
| 819 | wq->cpu_wq = alloc_percpu(struct cpu_workqueue_struct); |
| 820 | if (!wq->cpu_wq) { |
| 821 | kfree(wq); |
| 822 | return NULL; |
| 823 | } |
| 824 | |
| 825 | wq->name = name; |
Johannes Berg | eb13ba8 | 2008-01-16 09:51:58 +0100 | [diff] [blame] | 826 | lockdep_init_map(&wq->lockdep_map, lock_name, key, 0); |
Oleg Nesterov | cce1a16 | 2007-05-09 02:34:13 -0700 | [diff] [blame] | 827 | wq->singlethread = singlethread; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 828 | wq->freezeable = freezeable; |
Oleg Nesterov | cce1a16 | 2007-05-09 02:34:13 -0700 | [diff] [blame] | 829 | INIT_LIST_HEAD(&wq->list); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 830 | |
| 831 | if (singlethread) { |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 832 | cwq = init_cpu_workqueue(wq, singlethread_cpu); |
| 833 | err = create_workqueue_thread(cwq, singlethread_cpu); |
Oleg Nesterov | 06ba38a | 2007-05-09 02:34:15 -0700 | [diff] [blame] | 834 | start_workqueue_thread(cwq, -1); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 835 | } else { |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 836 | cpu_maps_update_begin(); |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 837 | spin_lock(&workqueue_lock); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 838 | list_add(&wq->list, &workqueues); |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 839 | spin_unlock(&workqueue_lock); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 840 | |
| 841 | for_each_possible_cpu(cpu) { |
| 842 | cwq = init_cpu_workqueue(wq, cpu); |
| 843 | if (err || !cpu_online(cpu)) |
| 844 | continue; |
| 845 | err = create_workqueue_thread(cwq, cpu); |
Oleg Nesterov | 06ba38a | 2007-05-09 02:34:15 -0700 | [diff] [blame] | 846 | start_workqueue_thread(cwq, cpu); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 847 | } |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 848 | cpu_maps_update_done(); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 849 | } |
| 850 | |
| 851 | if (err) { |
| 852 | destroy_workqueue(wq); |
| 853 | wq = NULL; |
| 854 | } |
| 855 | return wq; |
| 856 | } |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 857 | EXPORT_SYMBOL_GPL(__create_workqueue_key); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 858 | |
Oleg Nesterov | 1e35eaa | 2008-04-29 01:00:28 -0700 | [diff] [blame] | 859 | static void cleanup_workqueue_thread(struct cpu_workqueue_struct *cwq) |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 860 | { |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 861 | /* |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 862 | * Our caller is either destroy_workqueue() or CPU_POST_DEAD, |
| 863 | * cpu_add_remove_lock protects cwq->thread. |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 864 | */ |
| 865 | if (cwq->thread == NULL) |
| 866 | return; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 867 | |
Johannes Berg | 4e6045f | 2007-10-18 23:39:55 -0700 | [diff] [blame] | 868 | lock_acquire(&cwq->wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_); |
| 869 | lock_release(&cwq->wq->lockdep_map, 1, _THIS_IP_); |
| 870 | |
Oleg Nesterov | 13c2216 | 2007-07-17 04:03:55 -0700 | [diff] [blame] | 871 | flush_cpu_workqueue(cwq); |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 872 | /* |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 873 | * 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] | 874 | * a concurrent flush_workqueue() can insert a barrier after us. |
| 875 | * However, in that case run_workqueue() won't return and check |
| 876 | * kthread_should_stop() until it flushes all work_struct's. |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 877 | * When ->worklist becomes empty it is safe to exit because no |
| 878 | * more work_structs can be queued on this cwq: flush_workqueue |
| 879 | * checks list_empty(), and a "normal" queue_work() can't use |
| 880 | * a dead CPU. |
| 881 | */ |
Oleg Nesterov | 1444196 | 2007-05-23 13:57:57 -0700 | [diff] [blame] | 882 | kthread_stop(cwq->thread); |
| 883 | cwq->thread = NULL; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 884 | } |
| 885 | |
| 886 | /** |
| 887 | * destroy_workqueue - safely terminate a workqueue |
| 888 | * @wq: target workqueue |
| 889 | * |
| 890 | * Safely destroy a workqueue. All work currently pending will be done first. |
| 891 | */ |
| 892 | void destroy_workqueue(struct workqueue_struct *wq) |
| 893 | { |
Oleg Nesterov | b1f4ec1 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 894 | const cpumask_t *cpu_map = wq_cpu_map(wq); |
Oleg Nesterov | b1f4ec1 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 895 | int cpu; |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 896 | |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 897 | cpu_maps_update_begin(); |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 898 | spin_lock(&workqueue_lock); |
Oleg Nesterov | b1f4ec1 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 899 | list_del(&wq->list); |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 900 | spin_unlock(&workqueue_lock); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 901 | |
Mike Travis | 363ab6f | 2008-05-12 21:21:13 +0200 | [diff] [blame] | 902 | for_each_cpu_mask_nr(cpu, *cpu_map) |
Oleg Nesterov | 1e35eaa | 2008-04-29 01:00:28 -0700 | [diff] [blame] | 903 | cleanup_workqueue_thread(per_cpu_ptr(wq->cpu_wq, cpu)); |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 904 | cpu_maps_update_done(); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 905 | |
| 906 | free_percpu(wq->cpu_wq); |
| 907 | kfree(wq); |
| 908 | } |
| 909 | EXPORT_SYMBOL_GPL(destroy_workqueue); |
| 910 | |
| 911 | static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, |
| 912 | unsigned long action, |
| 913 | void *hcpu) |
| 914 | { |
| 915 | unsigned int cpu = (unsigned long)hcpu; |
| 916 | struct cpu_workqueue_struct *cwq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 917 | struct workqueue_struct *wq; |
| 918 | |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 919 | action &= ~CPU_TASKS_FROZEN; |
| 920 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 921 | switch (action) { |
| 922 | case CPU_UP_PREPARE: |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 923 | cpu_set(cpu, cpu_populated_map); |
| 924 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 925 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 926 | list_for_each_entry(wq, &workqueues, list) { |
| 927 | cwq = per_cpu_ptr(wq->cpu_wq, cpu); |
Christoph Lameter | 89ada67 | 2005-10-30 15:01:59 -0800 | [diff] [blame] | 928 | |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 929 | switch (action) { |
| 930 | case CPU_UP_PREPARE: |
| 931 | if (!create_workqueue_thread(cwq, cpu)) |
| 932 | break; |
Gautham R Shenoy | 95402b3 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 933 | printk(KERN_ERR "workqueue [%s] for %i failed\n", |
| 934 | wq->name, cpu); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 935 | return NOTIFY_BAD; |
| 936 | |
| 937 | case CPU_ONLINE: |
Oleg Nesterov | 06ba38a | 2007-05-09 02:34:15 -0700 | [diff] [blame] | 938 | start_workqueue_thread(cwq, cpu); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 939 | break; |
| 940 | |
| 941 | case CPU_UP_CANCELED: |
Oleg Nesterov | 06ba38a | 2007-05-09 02:34:15 -0700 | [diff] [blame] | 942 | start_workqueue_thread(cwq, -1); |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 943 | case CPU_POST_DEAD: |
Oleg Nesterov | 1e35eaa | 2008-04-29 01:00:28 -0700 | [diff] [blame] | 944 | cleanup_workqueue_thread(cwq); |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 945 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 946 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 947 | } |
| 948 | |
Oleg Nesterov | 00dfcaf | 2008-04-29 01:00:27 -0700 | [diff] [blame] | 949 | switch (action) { |
| 950 | case CPU_UP_CANCELED: |
Oleg Nesterov | 3da1c84 | 2008-07-25 01:47:50 -0700 | [diff] [blame] | 951 | case CPU_POST_DEAD: |
Oleg Nesterov | 00dfcaf | 2008-04-29 01:00:27 -0700 | [diff] [blame] | 952 | cpu_clear(cpu, cpu_populated_map); |
| 953 | } |
| 954 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 955 | return NOTIFY_OK; |
| 956 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 957 | |
Oleg Nesterov | c12920d | 2007-05-09 02:34:14 -0700 | [diff] [blame] | 958 | void __init init_workqueues(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 959 | { |
Oleg Nesterov | 3af24433 | 2007-05-09 02:34:09 -0700 | [diff] [blame] | 960 | cpu_populated_map = cpu_online_map; |
Nathan Lynch | f756d5e | 2006-01-08 01:05:12 -0800 | [diff] [blame] | 961 | singlethread_cpu = first_cpu(cpu_possible_map); |
Oleg Nesterov | b1f4ec1 | 2007-05-09 02:34:12 -0700 | [diff] [blame] | 962 | cpu_singlethread_map = cpumask_of_cpu(singlethread_cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 963 | hotcpu_notifier(workqueue_cpu_callback, 0); |
| 964 | keventd_wq = create_workqueue("events"); |
| 965 | BUG_ON(!keventd_wq); |
| 966 | } |