11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * linux/kernel/workqueue.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * Generic mechanism for defining kernel helper threads for running 51da177e4SLinus Torvalds * arbitrary tasks in process context. 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * Started by Ingo Molnar, Copyright (C) 2002 81da177e4SLinus Torvalds * 91da177e4SLinus Torvalds * Derived from the taskqueue/keventd code by: 101da177e4SLinus Torvalds * 111da177e4SLinus Torvalds * David Woodhouse <dwmw2@infradead.org> 121da177e4SLinus Torvalds * Andrew Morton <andrewm@uow.edu.au> 131da177e4SLinus Torvalds * Kai Petzke <wpp@marie.physik.tu-berlin.de> 141da177e4SLinus Torvalds * Theodore Ts'o <tytso@mit.edu> 1589ada679SChristoph Lameter * 1689ada679SChristoph Lameter * Made to use alloc_percpu by Christoph Lameter <clameter@sgi.com>. 171da177e4SLinus Torvalds */ 181da177e4SLinus Torvalds 191da177e4SLinus Torvalds #include <linux/module.h> 201da177e4SLinus Torvalds #include <linux/kernel.h> 211da177e4SLinus Torvalds #include <linux/sched.h> 221da177e4SLinus Torvalds #include <linux/init.h> 231da177e4SLinus Torvalds #include <linux/signal.h> 241da177e4SLinus Torvalds #include <linux/completion.h> 251da177e4SLinus Torvalds #include <linux/workqueue.h> 261da177e4SLinus Torvalds #include <linux/slab.h> 271da177e4SLinus Torvalds #include <linux/cpu.h> 281da177e4SLinus Torvalds #include <linux/notifier.h> 291da177e4SLinus Torvalds #include <linux/kthread.h> 301da177e4SLinus Torvalds 311da177e4SLinus Torvalds /* 321da177e4SLinus Torvalds * The per-CPU workqueue (if single thread, we always use cpu 0's). 331da177e4SLinus Torvalds * 341da177e4SLinus Torvalds * The sequence counters are for flush_scheduled_work(). It wants to wait 351da177e4SLinus Torvalds * until until all currently-scheduled works are completed, but it doesn't 361da177e4SLinus Torvalds * want to be livelocked by new, incoming ones. So it waits until 371da177e4SLinus Torvalds * remove_sequence is >= the insert_sequence which pertained when 381da177e4SLinus Torvalds * flush_scheduled_work() was called. 391da177e4SLinus Torvalds */ 401da177e4SLinus Torvalds struct cpu_workqueue_struct { 411da177e4SLinus Torvalds 421da177e4SLinus Torvalds spinlock_t lock; 431da177e4SLinus Torvalds 441da177e4SLinus Torvalds long remove_sequence; /* Least-recently added (next to run) */ 451da177e4SLinus Torvalds long insert_sequence; /* Next to add */ 461da177e4SLinus Torvalds 471da177e4SLinus Torvalds struct list_head worklist; 481da177e4SLinus Torvalds wait_queue_head_t more_work; 491da177e4SLinus Torvalds wait_queue_head_t work_done; 501da177e4SLinus Torvalds 511da177e4SLinus Torvalds struct workqueue_struct *wq; 521da177e4SLinus Torvalds task_t *thread; 531da177e4SLinus Torvalds 541da177e4SLinus Torvalds int run_depth; /* Detect run_workqueue() recursion depth */ 551da177e4SLinus Torvalds } ____cacheline_aligned; 561da177e4SLinus Torvalds 571da177e4SLinus Torvalds /* 581da177e4SLinus Torvalds * The externally visible workqueue abstraction is an array of 591da177e4SLinus Torvalds * per-CPU workqueues: 601da177e4SLinus Torvalds */ 611da177e4SLinus Torvalds struct workqueue_struct { 6289ada679SChristoph Lameter struct cpu_workqueue_struct *cpu_wq; 631da177e4SLinus Torvalds const char *name; 641da177e4SLinus Torvalds struct list_head list; /* Empty if single thread */ 651da177e4SLinus Torvalds }; 661da177e4SLinus Torvalds 671da177e4SLinus Torvalds /* All the per-cpu workqueues on the system, for hotplug cpu to add/remove 681da177e4SLinus Torvalds threads to each one as cpus come/go. */ 691da177e4SLinus Torvalds static DEFINE_SPINLOCK(workqueue_lock); 701da177e4SLinus Torvalds static LIST_HEAD(workqueues); 711da177e4SLinus Torvalds 721da177e4SLinus Torvalds /* If it's single threaded, it isn't in the list of workqueues. */ 731da177e4SLinus Torvalds static inline int is_single_threaded(struct workqueue_struct *wq) 741da177e4SLinus Torvalds { 751da177e4SLinus Torvalds return list_empty(&wq->list); 761da177e4SLinus Torvalds } 771da177e4SLinus Torvalds 781da177e4SLinus Torvalds /* Preempt must be disabled. */ 791da177e4SLinus Torvalds static void __queue_work(struct cpu_workqueue_struct *cwq, 801da177e4SLinus Torvalds struct work_struct *work) 811da177e4SLinus Torvalds { 821da177e4SLinus Torvalds unsigned long flags; 831da177e4SLinus Torvalds 841da177e4SLinus Torvalds spin_lock_irqsave(&cwq->lock, flags); 851da177e4SLinus Torvalds work->wq_data = cwq; 861da177e4SLinus Torvalds list_add_tail(&work->entry, &cwq->worklist); 871da177e4SLinus Torvalds cwq->insert_sequence++; 881da177e4SLinus Torvalds wake_up(&cwq->more_work); 891da177e4SLinus Torvalds spin_unlock_irqrestore(&cwq->lock, flags); 901da177e4SLinus Torvalds } 911da177e4SLinus Torvalds 921da177e4SLinus Torvalds /* 931da177e4SLinus Torvalds * Queue work on a workqueue. Return non-zero if it was successfully 941da177e4SLinus Torvalds * added. 951da177e4SLinus Torvalds * 961da177e4SLinus Torvalds * We queue the work to the CPU it was submitted, but there is no 971da177e4SLinus Torvalds * guarantee that it will be processed by that CPU. 981da177e4SLinus Torvalds */ 991da177e4SLinus Torvalds int fastcall queue_work(struct workqueue_struct *wq, struct work_struct *work) 1001da177e4SLinus Torvalds { 1011da177e4SLinus Torvalds int ret = 0, cpu = get_cpu(); 1021da177e4SLinus Torvalds 1031da177e4SLinus Torvalds if (!test_and_set_bit(0, &work->pending)) { 1041da177e4SLinus Torvalds if (unlikely(is_single_threaded(wq))) 105bce61dd4SBen Collins cpu = any_online_cpu(cpu_online_map); 1061da177e4SLinus Torvalds BUG_ON(!list_empty(&work->entry)); 10789ada679SChristoph Lameter __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work); 1081da177e4SLinus Torvalds ret = 1; 1091da177e4SLinus Torvalds } 1101da177e4SLinus Torvalds put_cpu(); 1111da177e4SLinus Torvalds return ret; 1121da177e4SLinus Torvalds } 1131da177e4SLinus Torvalds 1141da177e4SLinus Torvalds static void delayed_work_timer_fn(unsigned long __data) 1151da177e4SLinus Torvalds { 1161da177e4SLinus Torvalds struct work_struct *work = (struct work_struct *)__data; 1171da177e4SLinus Torvalds struct workqueue_struct *wq = work->wq_data; 1181da177e4SLinus Torvalds int cpu = smp_processor_id(); 1191da177e4SLinus Torvalds 1201da177e4SLinus Torvalds if (unlikely(is_single_threaded(wq))) 121bce61dd4SBen Collins cpu = any_online_cpu(cpu_online_map); 1221da177e4SLinus Torvalds 12389ada679SChristoph Lameter __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work); 1241da177e4SLinus Torvalds } 1251da177e4SLinus Torvalds 1261da177e4SLinus Torvalds int fastcall queue_delayed_work(struct workqueue_struct *wq, 1271da177e4SLinus Torvalds struct work_struct *work, unsigned long delay) 1281da177e4SLinus Torvalds { 1291da177e4SLinus Torvalds int ret = 0; 1301da177e4SLinus Torvalds struct timer_list *timer = &work->timer; 1311da177e4SLinus Torvalds 1321da177e4SLinus Torvalds if (!test_and_set_bit(0, &work->pending)) { 1331da177e4SLinus Torvalds BUG_ON(timer_pending(timer)); 1341da177e4SLinus Torvalds BUG_ON(!list_empty(&work->entry)); 1351da177e4SLinus Torvalds 1361da177e4SLinus Torvalds /* This stores wq for the moment, for the timer_fn */ 1371da177e4SLinus Torvalds work->wq_data = wq; 1381da177e4SLinus Torvalds timer->expires = jiffies + delay; 1391da177e4SLinus Torvalds timer->data = (unsigned long)work; 1401da177e4SLinus Torvalds timer->function = delayed_work_timer_fn; 1411da177e4SLinus Torvalds add_timer(timer); 1421da177e4SLinus Torvalds ret = 1; 1431da177e4SLinus Torvalds } 1441da177e4SLinus Torvalds return ret; 1451da177e4SLinus Torvalds } 1461da177e4SLinus Torvalds 1471da177e4SLinus Torvalds static inline void run_workqueue(struct cpu_workqueue_struct *cwq) 1481da177e4SLinus Torvalds { 1491da177e4SLinus Torvalds unsigned long flags; 1501da177e4SLinus Torvalds 1511da177e4SLinus Torvalds /* 1521da177e4SLinus Torvalds * Keep taking off work from the queue until 1531da177e4SLinus Torvalds * done. 1541da177e4SLinus Torvalds */ 1551da177e4SLinus Torvalds spin_lock_irqsave(&cwq->lock, flags); 1561da177e4SLinus Torvalds cwq->run_depth++; 1571da177e4SLinus Torvalds if (cwq->run_depth > 3) { 1581da177e4SLinus Torvalds /* morton gets to eat his hat */ 1591da177e4SLinus Torvalds printk("%s: recursion depth exceeded: %d\n", 1601da177e4SLinus Torvalds __FUNCTION__, cwq->run_depth); 1611da177e4SLinus Torvalds dump_stack(); 1621da177e4SLinus Torvalds } 1631da177e4SLinus Torvalds while (!list_empty(&cwq->worklist)) { 1641da177e4SLinus Torvalds struct work_struct *work = list_entry(cwq->worklist.next, 1651da177e4SLinus Torvalds struct work_struct, entry); 1661da177e4SLinus Torvalds void (*f) (void *) = work->func; 1671da177e4SLinus Torvalds void *data = work->data; 1681da177e4SLinus Torvalds 1691da177e4SLinus Torvalds list_del_init(cwq->worklist.next); 1701da177e4SLinus Torvalds spin_unlock_irqrestore(&cwq->lock, flags); 1711da177e4SLinus Torvalds 1721da177e4SLinus Torvalds BUG_ON(work->wq_data != cwq); 1731da177e4SLinus Torvalds clear_bit(0, &work->pending); 1741da177e4SLinus Torvalds f(data); 1751da177e4SLinus Torvalds 1761da177e4SLinus Torvalds spin_lock_irqsave(&cwq->lock, flags); 1771da177e4SLinus Torvalds cwq->remove_sequence++; 1781da177e4SLinus Torvalds wake_up(&cwq->work_done); 1791da177e4SLinus Torvalds } 1801da177e4SLinus Torvalds cwq->run_depth--; 1811da177e4SLinus Torvalds spin_unlock_irqrestore(&cwq->lock, flags); 1821da177e4SLinus Torvalds } 1831da177e4SLinus Torvalds 1841da177e4SLinus Torvalds static int worker_thread(void *__cwq) 1851da177e4SLinus Torvalds { 1861da177e4SLinus Torvalds struct cpu_workqueue_struct *cwq = __cwq; 1871da177e4SLinus Torvalds DECLARE_WAITQUEUE(wait, current); 1881da177e4SLinus Torvalds struct k_sigaction sa; 1891da177e4SLinus Torvalds sigset_t blocked; 1901da177e4SLinus Torvalds 1911da177e4SLinus Torvalds current->flags |= PF_NOFREEZE; 1921da177e4SLinus Torvalds 1931da177e4SLinus Torvalds set_user_nice(current, -5); 1941da177e4SLinus Torvalds 1951da177e4SLinus Torvalds /* Block and flush all signals */ 1961da177e4SLinus Torvalds sigfillset(&blocked); 1971da177e4SLinus Torvalds sigprocmask(SIG_BLOCK, &blocked, NULL); 1981da177e4SLinus Torvalds flush_signals(current); 1991da177e4SLinus Torvalds 2001da177e4SLinus Torvalds /* SIG_IGN makes children autoreap: see do_notify_parent(). */ 2011da177e4SLinus Torvalds sa.sa.sa_handler = SIG_IGN; 2021da177e4SLinus Torvalds sa.sa.sa_flags = 0; 2031da177e4SLinus Torvalds siginitset(&sa.sa.sa_mask, sigmask(SIGCHLD)); 2041da177e4SLinus Torvalds do_sigaction(SIGCHLD, &sa, (struct k_sigaction *)0); 2051da177e4SLinus Torvalds 2061da177e4SLinus Torvalds set_current_state(TASK_INTERRUPTIBLE); 2071da177e4SLinus Torvalds while (!kthread_should_stop()) { 2081da177e4SLinus Torvalds add_wait_queue(&cwq->more_work, &wait); 2091da177e4SLinus Torvalds if (list_empty(&cwq->worklist)) 2101da177e4SLinus Torvalds schedule(); 2111da177e4SLinus Torvalds else 2121da177e4SLinus Torvalds __set_current_state(TASK_RUNNING); 2131da177e4SLinus Torvalds remove_wait_queue(&cwq->more_work, &wait); 2141da177e4SLinus Torvalds 2151da177e4SLinus Torvalds if (!list_empty(&cwq->worklist)) 2161da177e4SLinus Torvalds run_workqueue(cwq); 2171da177e4SLinus Torvalds set_current_state(TASK_INTERRUPTIBLE); 2181da177e4SLinus Torvalds } 2191da177e4SLinus Torvalds __set_current_state(TASK_RUNNING); 2201da177e4SLinus Torvalds return 0; 2211da177e4SLinus Torvalds } 2221da177e4SLinus Torvalds 2231da177e4SLinus Torvalds static void flush_cpu_workqueue(struct cpu_workqueue_struct *cwq) 2241da177e4SLinus Torvalds { 2251da177e4SLinus Torvalds if (cwq->thread == current) { 2261da177e4SLinus Torvalds /* 2271da177e4SLinus Torvalds * Probably keventd trying to flush its own queue. So simply run 2281da177e4SLinus Torvalds * it by hand rather than deadlocking. 2291da177e4SLinus Torvalds */ 2301da177e4SLinus Torvalds run_workqueue(cwq); 2311da177e4SLinus Torvalds } else { 2321da177e4SLinus Torvalds DEFINE_WAIT(wait); 2331da177e4SLinus Torvalds long sequence_needed; 2341da177e4SLinus Torvalds 2351da177e4SLinus Torvalds spin_lock_irq(&cwq->lock); 2361da177e4SLinus Torvalds sequence_needed = cwq->insert_sequence; 2371da177e4SLinus Torvalds 2381da177e4SLinus Torvalds while (sequence_needed - cwq->remove_sequence > 0) { 2391da177e4SLinus Torvalds prepare_to_wait(&cwq->work_done, &wait, 2401da177e4SLinus Torvalds TASK_UNINTERRUPTIBLE); 2411da177e4SLinus Torvalds spin_unlock_irq(&cwq->lock); 2421da177e4SLinus Torvalds schedule(); 2431da177e4SLinus Torvalds spin_lock_irq(&cwq->lock); 2441da177e4SLinus Torvalds } 2451da177e4SLinus Torvalds finish_wait(&cwq->work_done, &wait); 2461da177e4SLinus Torvalds spin_unlock_irq(&cwq->lock); 2471da177e4SLinus Torvalds } 2481da177e4SLinus Torvalds } 2491da177e4SLinus Torvalds 2501da177e4SLinus Torvalds /* 2511da177e4SLinus Torvalds * flush_workqueue - ensure that any scheduled work has run to completion. 2521da177e4SLinus Torvalds * 2531da177e4SLinus Torvalds * Forces execution of the workqueue and blocks until its completion. 2541da177e4SLinus Torvalds * This is typically used in driver shutdown handlers. 2551da177e4SLinus Torvalds * 2561da177e4SLinus Torvalds * This function will sample each workqueue's current insert_sequence number and 2571da177e4SLinus Torvalds * will sleep until the head sequence is greater than or equal to that. This 2581da177e4SLinus Torvalds * means that we sleep until all works which were queued on entry have been 2591da177e4SLinus Torvalds * handled, but we are not livelocked by new incoming ones. 2601da177e4SLinus Torvalds * 2611da177e4SLinus Torvalds * This function used to run the workqueues itself. Now we just wait for the 2621da177e4SLinus Torvalds * helper threads to do it. 2631da177e4SLinus Torvalds */ 2641da177e4SLinus Torvalds void fastcall flush_workqueue(struct workqueue_struct *wq) 2651da177e4SLinus Torvalds { 2661da177e4SLinus Torvalds might_sleep(); 2671da177e4SLinus Torvalds 2681da177e4SLinus Torvalds if (is_single_threaded(wq)) { 269bce61dd4SBen Collins /* Always use first cpu's area. */ 270bce61dd4SBen Collins flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, any_online_cpu(cpu_online_map))); 2711da177e4SLinus Torvalds } else { 2721da177e4SLinus Torvalds int cpu; 2731da177e4SLinus Torvalds 2741da177e4SLinus Torvalds lock_cpu_hotplug(); 2751da177e4SLinus Torvalds for_each_online_cpu(cpu) 27689ada679SChristoph Lameter flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu)); 2771da177e4SLinus Torvalds unlock_cpu_hotplug(); 2781da177e4SLinus Torvalds } 2791da177e4SLinus Torvalds } 2801da177e4SLinus Torvalds 2811da177e4SLinus Torvalds static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq, 2821da177e4SLinus Torvalds int cpu) 2831da177e4SLinus Torvalds { 28489ada679SChristoph Lameter struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); 2851da177e4SLinus Torvalds struct task_struct *p; 2861da177e4SLinus Torvalds 2871da177e4SLinus Torvalds spin_lock_init(&cwq->lock); 2881da177e4SLinus Torvalds cwq->wq = wq; 2891da177e4SLinus Torvalds cwq->thread = NULL; 2901da177e4SLinus Torvalds cwq->insert_sequence = 0; 2911da177e4SLinus Torvalds cwq->remove_sequence = 0; 2921da177e4SLinus Torvalds INIT_LIST_HEAD(&cwq->worklist); 2931da177e4SLinus Torvalds init_waitqueue_head(&cwq->more_work); 2941da177e4SLinus Torvalds init_waitqueue_head(&cwq->work_done); 2951da177e4SLinus Torvalds 2961da177e4SLinus Torvalds if (is_single_threaded(wq)) 2971da177e4SLinus Torvalds p = kthread_create(worker_thread, cwq, "%s", wq->name); 2981da177e4SLinus Torvalds else 2991da177e4SLinus Torvalds p = kthread_create(worker_thread, cwq, "%s/%d", wq->name, cpu); 3001da177e4SLinus Torvalds if (IS_ERR(p)) 3011da177e4SLinus Torvalds return NULL; 3021da177e4SLinus Torvalds cwq->thread = p; 3031da177e4SLinus Torvalds return p; 3041da177e4SLinus Torvalds } 3051da177e4SLinus Torvalds 3061da177e4SLinus Torvalds struct workqueue_struct *__create_workqueue(const char *name, 3071da177e4SLinus Torvalds int singlethread) 3081da177e4SLinus Torvalds { 3091da177e4SLinus Torvalds int cpu, destroy = 0; 3101da177e4SLinus Torvalds struct workqueue_struct *wq; 3111da177e4SLinus Torvalds struct task_struct *p; 3121da177e4SLinus Torvalds 313dd392710SPekka J Enberg wq = kzalloc(sizeof(*wq), GFP_KERNEL); 3141da177e4SLinus Torvalds if (!wq) 3151da177e4SLinus Torvalds return NULL; 3161da177e4SLinus Torvalds 31789ada679SChristoph Lameter wq->cpu_wq = alloc_percpu(struct cpu_workqueue_struct); 3181da177e4SLinus Torvalds wq->name = name; 3191da177e4SLinus Torvalds /* We don't need the distraction of CPUs appearing and vanishing. */ 3201da177e4SLinus Torvalds lock_cpu_hotplug(); 3211da177e4SLinus Torvalds if (singlethread) { 3221da177e4SLinus Torvalds INIT_LIST_HEAD(&wq->list); 323bce61dd4SBen Collins p = create_workqueue_thread(wq, any_online_cpu(cpu_online_map)); 3241da177e4SLinus Torvalds if (!p) 3251da177e4SLinus Torvalds destroy = 1; 3261da177e4SLinus Torvalds else 3271da177e4SLinus Torvalds wake_up_process(p); 3281da177e4SLinus Torvalds } else { 3291da177e4SLinus Torvalds spin_lock(&workqueue_lock); 3301da177e4SLinus Torvalds list_add(&wq->list, &workqueues); 3311da177e4SLinus Torvalds spin_unlock(&workqueue_lock); 3321da177e4SLinus Torvalds for_each_online_cpu(cpu) { 3331da177e4SLinus Torvalds p = create_workqueue_thread(wq, cpu); 3341da177e4SLinus Torvalds if (p) { 3351da177e4SLinus Torvalds kthread_bind(p, cpu); 3361da177e4SLinus Torvalds wake_up_process(p); 3371da177e4SLinus Torvalds } else 3381da177e4SLinus Torvalds destroy = 1; 3391da177e4SLinus Torvalds } 3401da177e4SLinus Torvalds } 3411da177e4SLinus Torvalds unlock_cpu_hotplug(); 3421da177e4SLinus Torvalds 3431da177e4SLinus Torvalds /* 3441da177e4SLinus Torvalds * Was there any error during startup? If yes then clean up: 3451da177e4SLinus Torvalds */ 3461da177e4SLinus Torvalds if (destroy) { 3471da177e4SLinus Torvalds destroy_workqueue(wq); 3481da177e4SLinus Torvalds wq = NULL; 3491da177e4SLinus Torvalds } 3501da177e4SLinus Torvalds return wq; 3511da177e4SLinus Torvalds } 3521da177e4SLinus Torvalds 3531da177e4SLinus Torvalds static void cleanup_workqueue_thread(struct workqueue_struct *wq, int cpu) 3541da177e4SLinus Torvalds { 3551da177e4SLinus Torvalds struct cpu_workqueue_struct *cwq; 3561da177e4SLinus Torvalds unsigned long flags; 3571da177e4SLinus Torvalds struct task_struct *p; 3581da177e4SLinus Torvalds 35989ada679SChristoph Lameter cwq = per_cpu_ptr(wq->cpu_wq, cpu); 3601da177e4SLinus Torvalds spin_lock_irqsave(&cwq->lock, flags); 3611da177e4SLinus Torvalds p = cwq->thread; 3621da177e4SLinus Torvalds cwq->thread = NULL; 3631da177e4SLinus Torvalds spin_unlock_irqrestore(&cwq->lock, flags); 3641da177e4SLinus Torvalds if (p) 3651da177e4SLinus Torvalds kthread_stop(p); 3661da177e4SLinus Torvalds } 3671da177e4SLinus Torvalds 3681da177e4SLinus Torvalds void destroy_workqueue(struct workqueue_struct *wq) 3691da177e4SLinus Torvalds { 3701da177e4SLinus Torvalds int cpu; 3711da177e4SLinus Torvalds 3721da177e4SLinus Torvalds flush_workqueue(wq); 3731da177e4SLinus Torvalds 3741da177e4SLinus Torvalds /* We don't need the distraction of CPUs appearing and vanishing. */ 3751da177e4SLinus Torvalds lock_cpu_hotplug(); 3761da177e4SLinus Torvalds if (is_single_threaded(wq)) 377bce61dd4SBen Collins cleanup_workqueue_thread(wq, any_online_cpu(cpu_online_map)); 3781da177e4SLinus Torvalds else { 3791da177e4SLinus Torvalds for_each_online_cpu(cpu) 3801da177e4SLinus Torvalds cleanup_workqueue_thread(wq, cpu); 3811da177e4SLinus Torvalds spin_lock(&workqueue_lock); 3821da177e4SLinus Torvalds list_del(&wq->list); 3831da177e4SLinus Torvalds spin_unlock(&workqueue_lock); 3841da177e4SLinus Torvalds } 3851da177e4SLinus Torvalds unlock_cpu_hotplug(); 38689ada679SChristoph Lameter free_percpu(wq->cpu_wq); 3871da177e4SLinus Torvalds kfree(wq); 3881da177e4SLinus Torvalds } 3891da177e4SLinus Torvalds 3901da177e4SLinus Torvalds static struct workqueue_struct *keventd_wq; 3911da177e4SLinus Torvalds 3921da177e4SLinus Torvalds int fastcall schedule_work(struct work_struct *work) 3931da177e4SLinus Torvalds { 3941da177e4SLinus Torvalds return queue_work(keventd_wq, work); 3951da177e4SLinus Torvalds } 3961da177e4SLinus Torvalds 3971da177e4SLinus Torvalds int fastcall schedule_delayed_work(struct work_struct *work, unsigned long delay) 3981da177e4SLinus Torvalds { 3991da177e4SLinus Torvalds return queue_delayed_work(keventd_wq, work, delay); 4001da177e4SLinus Torvalds } 4011da177e4SLinus Torvalds 4021da177e4SLinus Torvalds int schedule_delayed_work_on(int cpu, 4031da177e4SLinus Torvalds struct work_struct *work, unsigned long delay) 4041da177e4SLinus Torvalds { 4051da177e4SLinus Torvalds int ret = 0; 4061da177e4SLinus Torvalds struct timer_list *timer = &work->timer; 4071da177e4SLinus Torvalds 4081da177e4SLinus Torvalds if (!test_and_set_bit(0, &work->pending)) { 4091da177e4SLinus Torvalds BUG_ON(timer_pending(timer)); 4101da177e4SLinus Torvalds BUG_ON(!list_empty(&work->entry)); 4111da177e4SLinus Torvalds /* This stores keventd_wq for the moment, for the timer_fn */ 4121da177e4SLinus Torvalds work->wq_data = keventd_wq; 4131da177e4SLinus Torvalds timer->expires = jiffies + delay; 4141da177e4SLinus Torvalds timer->data = (unsigned long)work; 4151da177e4SLinus Torvalds timer->function = delayed_work_timer_fn; 4161da177e4SLinus Torvalds add_timer_on(timer, cpu); 4171da177e4SLinus Torvalds ret = 1; 4181da177e4SLinus Torvalds } 4191da177e4SLinus Torvalds return ret; 4201da177e4SLinus Torvalds } 4211da177e4SLinus Torvalds 42215316ba8SChristoph Lameter int schedule_on_each_cpu(void (*func) (void *info), void *info) 42315316ba8SChristoph Lameter { 42415316ba8SChristoph Lameter int cpu; 42515316ba8SChristoph Lameter struct work_struct *work; 42615316ba8SChristoph Lameter 42715316ba8SChristoph Lameter work = kmalloc(NR_CPUS * sizeof(struct work_struct), GFP_KERNEL); 42815316ba8SChristoph Lameter 42915316ba8SChristoph Lameter if (!work) 43015316ba8SChristoph Lameter return -ENOMEM; 43115316ba8SChristoph Lameter for_each_online_cpu(cpu) { 43215316ba8SChristoph Lameter INIT_WORK(work + cpu, func, info); 43315316ba8SChristoph Lameter __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu), 43415316ba8SChristoph Lameter work + cpu); 43515316ba8SChristoph Lameter } 43615316ba8SChristoph Lameter flush_workqueue(keventd_wq); 43715316ba8SChristoph Lameter kfree(work); 43815316ba8SChristoph Lameter return 0; 43915316ba8SChristoph Lameter } 44015316ba8SChristoph Lameter 4411da177e4SLinus Torvalds void flush_scheduled_work(void) 4421da177e4SLinus Torvalds { 4431da177e4SLinus Torvalds flush_workqueue(keventd_wq); 4441da177e4SLinus Torvalds } 4451da177e4SLinus Torvalds 4461da177e4SLinus Torvalds /** 4471da177e4SLinus Torvalds * cancel_rearming_delayed_workqueue - reliably kill off a delayed 4481da177e4SLinus Torvalds * work whose handler rearms the delayed work. 4491da177e4SLinus Torvalds * @wq: the controlling workqueue structure 4501da177e4SLinus Torvalds * @work: the delayed work struct 4511da177e4SLinus Torvalds */ 45281ddef77SJames Bottomley void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq, 4531da177e4SLinus Torvalds struct work_struct *work) 4541da177e4SLinus Torvalds { 4551da177e4SLinus Torvalds while (!cancel_delayed_work(work)) 4561da177e4SLinus Torvalds flush_workqueue(wq); 4571da177e4SLinus Torvalds } 45881ddef77SJames Bottomley EXPORT_SYMBOL(cancel_rearming_delayed_workqueue); 4591da177e4SLinus Torvalds 4601da177e4SLinus Torvalds /** 4611da177e4SLinus Torvalds * cancel_rearming_delayed_work - reliably kill off a delayed keventd 4621da177e4SLinus Torvalds * work whose handler rearms the delayed work. 4631da177e4SLinus Torvalds * @work: the delayed work struct 4641da177e4SLinus Torvalds */ 4651da177e4SLinus Torvalds void cancel_rearming_delayed_work(struct work_struct *work) 4661da177e4SLinus Torvalds { 4671da177e4SLinus Torvalds cancel_rearming_delayed_workqueue(keventd_wq, work); 4681da177e4SLinus Torvalds } 4691da177e4SLinus Torvalds EXPORT_SYMBOL(cancel_rearming_delayed_work); 4701da177e4SLinus Torvalds 4711da177e4SLinus Torvalds int keventd_up(void) 4721da177e4SLinus Torvalds { 4731da177e4SLinus Torvalds return keventd_wq != NULL; 4741da177e4SLinus Torvalds } 4751da177e4SLinus Torvalds 4761da177e4SLinus Torvalds int current_is_keventd(void) 4771da177e4SLinus Torvalds { 4781da177e4SLinus Torvalds struct cpu_workqueue_struct *cwq; 4791da177e4SLinus Torvalds int cpu = smp_processor_id(); /* preempt-safe: keventd is per-cpu */ 4801da177e4SLinus Torvalds int ret = 0; 4811da177e4SLinus Torvalds 4821da177e4SLinus Torvalds BUG_ON(!keventd_wq); 4831da177e4SLinus Torvalds 48489ada679SChristoph Lameter cwq = per_cpu_ptr(keventd_wq->cpu_wq, cpu); 4851da177e4SLinus Torvalds if (current == cwq->thread) 4861da177e4SLinus Torvalds ret = 1; 4871da177e4SLinus Torvalds 4881da177e4SLinus Torvalds return ret; 4891da177e4SLinus Torvalds 4901da177e4SLinus Torvalds } 4911da177e4SLinus Torvalds 4921da177e4SLinus Torvalds #ifdef CONFIG_HOTPLUG_CPU 4931da177e4SLinus Torvalds /* Take the work from this (downed) CPU. */ 4941da177e4SLinus Torvalds static void take_over_work(struct workqueue_struct *wq, unsigned int cpu) 4951da177e4SLinus Torvalds { 49689ada679SChristoph Lameter struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); 4971da177e4SLinus Torvalds LIST_HEAD(list); 4981da177e4SLinus Torvalds struct work_struct *work; 4991da177e4SLinus Torvalds 5001da177e4SLinus Torvalds spin_lock_irq(&cwq->lock); 5011da177e4SLinus Torvalds list_splice_init(&cwq->worklist, &list); 5021da177e4SLinus Torvalds 5031da177e4SLinus Torvalds while (!list_empty(&list)) { 5041da177e4SLinus Torvalds printk("Taking work for %s\n", wq->name); 5051da177e4SLinus Torvalds work = list_entry(list.next,struct work_struct,entry); 5061da177e4SLinus Torvalds list_del(&work->entry); 50789ada679SChristoph Lameter __queue_work(per_cpu_ptr(wq->cpu_wq, smp_processor_id()), work); 5081da177e4SLinus Torvalds } 5091da177e4SLinus Torvalds spin_unlock_irq(&cwq->lock); 5101da177e4SLinus Torvalds } 5111da177e4SLinus Torvalds 5121da177e4SLinus Torvalds /* We're holding the cpucontrol mutex here */ 5131da177e4SLinus Torvalds static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, 5141da177e4SLinus Torvalds unsigned long action, 5151da177e4SLinus Torvalds void *hcpu) 5161da177e4SLinus Torvalds { 5171da177e4SLinus Torvalds unsigned int hotcpu = (unsigned long)hcpu; 5181da177e4SLinus Torvalds struct workqueue_struct *wq; 5191da177e4SLinus Torvalds 5201da177e4SLinus Torvalds switch (action) { 5211da177e4SLinus Torvalds case CPU_UP_PREPARE: 5221da177e4SLinus Torvalds /* Create a new workqueue thread for it. */ 5231da177e4SLinus Torvalds list_for_each_entry(wq, &workqueues, list) { 524230649daSMika Kukkonen if (!create_workqueue_thread(wq, hotcpu)) { 5251da177e4SLinus Torvalds printk("workqueue for %i failed\n", hotcpu); 5261da177e4SLinus Torvalds return NOTIFY_BAD; 5271da177e4SLinus Torvalds } 5281da177e4SLinus Torvalds } 5291da177e4SLinus Torvalds break; 5301da177e4SLinus Torvalds 5311da177e4SLinus Torvalds case CPU_ONLINE: 5321da177e4SLinus Torvalds /* Kick off worker threads. */ 5331da177e4SLinus Torvalds list_for_each_entry(wq, &workqueues, list) { 53489ada679SChristoph Lameter struct cpu_workqueue_struct *cwq; 53589ada679SChristoph Lameter 53689ada679SChristoph Lameter cwq = per_cpu_ptr(wq->cpu_wq, hotcpu); 53789ada679SChristoph Lameter kthread_bind(cwq->thread, hotcpu); 53889ada679SChristoph Lameter wake_up_process(cwq->thread); 5391da177e4SLinus Torvalds } 5401da177e4SLinus Torvalds break; 5411da177e4SLinus Torvalds 5421da177e4SLinus Torvalds case CPU_UP_CANCELED: 5431da177e4SLinus Torvalds list_for_each_entry(wq, &workqueues, list) { 5441da177e4SLinus Torvalds /* Unbind so it can run. */ 54589ada679SChristoph Lameter kthread_bind(per_cpu_ptr(wq->cpu_wq, hotcpu)->thread, 546a4c4af7cSHeiko Carstens any_online_cpu(cpu_online_map)); 5471da177e4SLinus Torvalds cleanup_workqueue_thread(wq, hotcpu); 5481da177e4SLinus Torvalds } 5491da177e4SLinus Torvalds break; 5501da177e4SLinus Torvalds 5511da177e4SLinus Torvalds case CPU_DEAD: 5521da177e4SLinus Torvalds list_for_each_entry(wq, &workqueues, list) 5531da177e4SLinus Torvalds cleanup_workqueue_thread(wq, hotcpu); 5541da177e4SLinus Torvalds list_for_each_entry(wq, &workqueues, list) 5551da177e4SLinus Torvalds take_over_work(wq, hotcpu); 5561da177e4SLinus Torvalds break; 5571da177e4SLinus Torvalds } 5581da177e4SLinus Torvalds 5591da177e4SLinus Torvalds return NOTIFY_OK; 5601da177e4SLinus Torvalds } 5611da177e4SLinus Torvalds #endif 5621da177e4SLinus Torvalds 5631da177e4SLinus Torvalds void init_workqueues(void) 5641da177e4SLinus Torvalds { 5651da177e4SLinus Torvalds hotcpu_notifier(workqueue_cpu_callback, 0); 5661da177e4SLinus Torvalds keventd_wq = create_workqueue("events"); 5671da177e4SLinus Torvalds BUG_ON(!keventd_wq); 5681da177e4SLinus Torvalds } 5691da177e4SLinus Torvalds 5701da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(__create_workqueue); 5711da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(queue_work); 5721da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(queue_delayed_work); 5731da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(flush_workqueue); 5741da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(destroy_workqueue); 5751da177e4SLinus Torvalds 5761da177e4SLinus Torvalds EXPORT_SYMBOL(schedule_work); 5771da177e4SLinus Torvalds EXPORT_SYMBOL(schedule_delayed_work); 5781da177e4SLinus Torvalds EXPORT_SYMBOL(schedule_delayed_work_on); 5791da177e4SLinus Torvalds EXPORT_SYMBOL(flush_scheduled_work); 580