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> 301fa44ecaSJames Bottomley #include <linux/hardirq.h> 3146934023SChristoph Lameter #include <linux/mempolicy.h> 32341a5958SRafael J. Wysocki #include <linux/freezer.h> 33d5abe669SPeter Zijlstra #include <linux/kallsyms.h> 34d5abe669SPeter Zijlstra #include <linux/debug_locks.h> 351da177e4SLinus Torvalds 361da177e4SLinus Torvalds /* 37f756d5e2SNathan Lynch * The per-CPU workqueue (if single thread, we always use the first 38f756d5e2SNathan Lynch * possible cpu). 391da177e4SLinus Torvalds * 401da177e4SLinus Torvalds * The sequence counters are for flush_scheduled_work(). It wants to wait 419f5d785eSRolf Eike Beer * until all currently-scheduled works are completed, but it doesn't 421da177e4SLinus Torvalds * want to be livelocked by new, incoming ones. So it waits until 431da177e4SLinus Torvalds * remove_sequence is >= the insert_sequence which pertained when 441da177e4SLinus Torvalds * flush_scheduled_work() was called. 451da177e4SLinus Torvalds */ 461da177e4SLinus Torvalds struct cpu_workqueue_struct { 471da177e4SLinus Torvalds 481da177e4SLinus Torvalds spinlock_t lock; 491da177e4SLinus Torvalds 501da177e4SLinus Torvalds long remove_sequence; /* Least-recently added (next to run) */ 511da177e4SLinus Torvalds long insert_sequence; /* Next to add */ 521da177e4SLinus Torvalds 531da177e4SLinus Torvalds struct list_head worklist; 541da177e4SLinus Torvalds wait_queue_head_t more_work; 551da177e4SLinus Torvalds wait_queue_head_t work_done; 561da177e4SLinus Torvalds 571da177e4SLinus Torvalds struct workqueue_struct *wq; 5836c8b586SIngo Molnar struct task_struct *thread; 591da177e4SLinus Torvalds 601da177e4SLinus Torvalds int run_depth; /* Detect run_workqueue() recursion depth */ 61341a5958SRafael J. Wysocki 62341a5958SRafael J. Wysocki int freezeable; /* Freeze the thread during suspend */ 631da177e4SLinus Torvalds } ____cacheline_aligned; 641da177e4SLinus Torvalds 651da177e4SLinus Torvalds /* 661da177e4SLinus Torvalds * The externally visible workqueue abstraction is an array of 671da177e4SLinus Torvalds * per-CPU workqueues: 681da177e4SLinus Torvalds */ 691da177e4SLinus Torvalds struct workqueue_struct { 7089ada679SChristoph Lameter struct cpu_workqueue_struct *cpu_wq; 711da177e4SLinus Torvalds const char *name; 721da177e4SLinus Torvalds struct list_head list; /* Empty if single thread */ 731da177e4SLinus Torvalds }; 741da177e4SLinus Torvalds 751da177e4SLinus Torvalds /* All the per-cpu workqueues on the system, for hotplug cpu to add/remove 761da177e4SLinus Torvalds threads to each one as cpus come/go. */ 779b41ea72SAndrew Morton static DEFINE_MUTEX(workqueue_mutex); 781da177e4SLinus Torvalds static LIST_HEAD(workqueues); 791da177e4SLinus Torvalds 80f756d5e2SNathan Lynch static int singlethread_cpu; 81f756d5e2SNathan Lynch 821da177e4SLinus Torvalds /* If it's single threaded, it isn't in the list of workqueues. */ 831da177e4SLinus Torvalds static inline int is_single_threaded(struct workqueue_struct *wq) 841da177e4SLinus Torvalds { 851da177e4SLinus Torvalds return list_empty(&wq->list); 861da177e4SLinus Torvalds } 871da177e4SLinus Torvalds 884594bf15SDavid Howells /* 894594bf15SDavid Howells * Set the workqueue on which a work item is to be run 904594bf15SDavid Howells * - Must *only* be called if the pending flag is set 914594bf15SDavid Howells */ 92365970a1SDavid Howells static inline void set_wq_data(struct work_struct *work, void *wq) 93365970a1SDavid Howells { 944594bf15SDavid Howells unsigned long new; 95365970a1SDavid Howells 964594bf15SDavid Howells BUG_ON(!work_pending(work)); 974594bf15SDavid Howells 98365970a1SDavid Howells new = (unsigned long) wq | (1UL << WORK_STRUCT_PENDING); 99a08727baSLinus Torvalds new |= WORK_STRUCT_FLAG_MASK & *work_data_bits(work); 100a08727baSLinus Torvalds atomic_long_set(&work->data, new); 101365970a1SDavid Howells } 102365970a1SDavid Howells 103365970a1SDavid Howells static inline void *get_wq_data(struct work_struct *work) 104365970a1SDavid Howells { 105a08727baSLinus Torvalds return (void *) (atomic_long_read(&work->data) & WORK_STRUCT_WQ_DATA_MASK); 106365970a1SDavid Howells } 107365970a1SDavid Howells 10868380b58SLinus Torvalds static int __run_work(struct cpu_workqueue_struct *cwq, struct work_struct *work) 10968380b58SLinus Torvalds { 11068380b58SLinus Torvalds int ret = 0; 11168380b58SLinus Torvalds unsigned long flags; 11268380b58SLinus Torvalds 11368380b58SLinus Torvalds spin_lock_irqsave(&cwq->lock, flags); 11468380b58SLinus Torvalds /* 11568380b58SLinus Torvalds * We need to re-validate the work info after we've gotten 11668380b58SLinus Torvalds * the cpu_workqueue lock. We can run the work now iff: 11768380b58SLinus Torvalds * 11868380b58SLinus Torvalds * - the wq_data still matches the cpu_workqueue_struct 11968380b58SLinus Torvalds * - AND the work is still marked pending 12068380b58SLinus Torvalds * - AND the work is still on a list (which will be this 12168380b58SLinus Torvalds * workqueue_struct list) 12268380b58SLinus Torvalds * 12368380b58SLinus Torvalds * All these conditions are important, because we 12468380b58SLinus Torvalds * need to protect against the work being run right 12568380b58SLinus Torvalds * now on another CPU (all but the last one might be 12668380b58SLinus Torvalds * true if it's currently running and has not been 12768380b58SLinus Torvalds * released yet, for example). 12868380b58SLinus Torvalds */ 12968380b58SLinus Torvalds if (get_wq_data(work) == cwq 13068380b58SLinus Torvalds && work_pending(work) 13168380b58SLinus Torvalds && !list_empty(&work->entry)) { 13268380b58SLinus Torvalds work_func_t f = work->func; 13368380b58SLinus Torvalds list_del_init(&work->entry); 13468380b58SLinus Torvalds spin_unlock_irqrestore(&cwq->lock, flags); 13568380b58SLinus Torvalds 136a08727baSLinus Torvalds if (!test_bit(WORK_STRUCT_NOAUTOREL, work_data_bits(work))) 13768380b58SLinus Torvalds work_release(work); 13868380b58SLinus Torvalds f(work); 13968380b58SLinus Torvalds 14068380b58SLinus Torvalds spin_lock_irqsave(&cwq->lock, flags); 14168380b58SLinus Torvalds cwq->remove_sequence++; 14268380b58SLinus Torvalds wake_up(&cwq->work_done); 14368380b58SLinus Torvalds ret = 1; 14468380b58SLinus Torvalds } 14568380b58SLinus Torvalds spin_unlock_irqrestore(&cwq->lock, flags); 14668380b58SLinus Torvalds return ret; 14768380b58SLinus Torvalds } 14868380b58SLinus Torvalds 14968380b58SLinus Torvalds /** 15068380b58SLinus Torvalds * run_scheduled_work - run scheduled work synchronously 15168380b58SLinus Torvalds * @work: work to run 15268380b58SLinus Torvalds * 15368380b58SLinus Torvalds * This checks if the work was pending, and runs it 15468380b58SLinus Torvalds * synchronously if so. It returns a boolean to indicate 15568380b58SLinus Torvalds * whether it had any scheduled work to run or not. 15668380b58SLinus Torvalds * 15768380b58SLinus Torvalds * NOTE! This _only_ works for normal work_structs. You 15868380b58SLinus Torvalds * CANNOT use this for delayed work, because the wq data 15968380b58SLinus Torvalds * for delayed work will not point properly to the per- 16068380b58SLinus Torvalds * CPU workqueue struct, but will change! 16168380b58SLinus Torvalds */ 16268380b58SLinus Torvalds int fastcall run_scheduled_work(struct work_struct *work) 16368380b58SLinus Torvalds { 16468380b58SLinus Torvalds for (;;) { 16568380b58SLinus Torvalds struct cpu_workqueue_struct *cwq; 16668380b58SLinus Torvalds 16768380b58SLinus Torvalds if (!work_pending(work)) 16868380b58SLinus Torvalds return 0; 16968380b58SLinus Torvalds if (list_empty(&work->entry)) 17068380b58SLinus Torvalds return 0; 17168380b58SLinus Torvalds /* NOTE! This depends intimately on __queue_work! */ 17268380b58SLinus Torvalds cwq = get_wq_data(work); 17368380b58SLinus Torvalds if (!cwq) 17468380b58SLinus Torvalds return 0; 17568380b58SLinus Torvalds if (__run_work(cwq, work)) 17668380b58SLinus Torvalds return 1; 17768380b58SLinus Torvalds } 17868380b58SLinus Torvalds } 17968380b58SLinus Torvalds EXPORT_SYMBOL(run_scheduled_work); 18068380b58SLinus Torvalds 1811da177e4SLinus Torvalds /* Preempt must be disabled. */ 1821da177e4SLinus Torvalds static void __queue_work(struct cpu_workqueue_struct *cwq, 1831da177e4SLinus Torvalds struct work_struct *work) 1841da177e4SLinus Torvalds { 1851da177e4SLinus Torvalds unsigned long flags; 1861da177e4SLinus Torvalds 1871da177e4SLinus Torvalds spin_lock_irqsave(&cwq->lock, flags); 188365970a1SDavid Howells set_wq_data(work, cwq); 1891da177e4SLinus Torvalds list_add_tail(&work->entry, &cwq->worklist); 1901da177e4SLinus Torvalds cwq->insert_sequence++; 1911da177e4SLinus Torvalds wake_up(&cwq->more_work); 1921da177e4SLinus Torvalds spin_unlock_irqrestore(&cwq->lock, flags); 1931da177e4SLinus Torvalds } 1941da177e4SLinus Torvalds 1950fcb78c2SRolf Eike Beer /** 1960fcb78c2SRolf Eike Beer * queue_work - queue work on a workqueue 1970fcb78c2SRolf Eike Beer * @wq: workqueue to use 1980fcb78c2SRolf Eike Beer * @work: work to queue 1990fcb78c2SRolf Eike Beer * 200057647fcSAlan Stern * Returns 0 if @work was already on a queue, non-zero otherwise. 2011da177e4SLinus Torvalds * 2021da177e4SLinus Torvalds * We queue the work to the CPU it was submitted, but there is no 2031da177e4SLinus Torvalds * guarantee that it will be processed by that CPU. 2041da177e4SLinus Torvalds */ 2051da177e4SLinus Torvalds int fastcall queue_work(struct workqueue_struct *wq, struct work_struct *work) 2061da177e4SLinus Torvalds { 2071da177e4SLinus Torvalds int ret = 0, cpu = get_cpu(); 2081da177e4SLinus Torvalds 209a08727baSLinus Torvalds if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) { 2101da177e4SLinus Torvalds if (unlikely(is_single_threaded(wq))) 211f756d5e2SNathan Lynch cpu = singlethread_cpu; 2121da177e4SLinus Torvalds BUG_ON(!list_empty(&work->entry)); 21389ada679SChristoph Lameter __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work); 2141da177e4SLinus Torvalds ret = 1; 2151da177e4SLinus Torvalds } 2161da177e4SLinus Torvalds put_cpu(); 2171da177e4SLinus Torvalds return ret; 2181da177e4SLinus Torvalds } 219ae90dd5dSDave Jones EXPORT_SYMBOL_GPL(queue_work); 2201da177e4SLinus Torvalds 2211da177e4SLinus Torvalds static void delayed_work_timer_fn(unsigned long __data) 2221da177e4SLinus Torvalds { 22352bad64dSDavid Howells struct delayed_work *dwork = (struct delayed_work *)__data; 224365970a1SDavid Howells struct workqueue_struct *wq = get_wq_data(&dwork->work); 2251da177e4SLinus Torvalds int cpu = smp_processor_id(); 2261da177e4SLinus Torvalds 2271da177e4SLinus Torvalds if (unlikely(is_single_threaded(wq))) 228f756d5e2SNathan Lynch cpu = singlethread_cpu; 2291da177e4SLinus Torvalds 23052bad64dSDavid Howells __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), &dwork->work); 2311da177e4SLinus Torvalds } 2321da177e4SLinus Torvalds 2330fcb78c2SRolf Eike Beer /** 2340fcb78c2SRolf Eike Beer * queue_delayed_work - queue work on a workqueue after delay 2350fcb78c2SRolf Eike Beer * @wq: workqueue to use 236af9997e4SRandy Dunlap * @dwork: delayable work to queue 2370fcb78c2SRolf Eike Beer * @delay: number of jiffies to wait before queueing 2380fcb78c2SRolf Eike Beer * 239057647fcSAlan Stern * Returns 0 if @work was already on a queue, non-zero otherwise. 2400fcb78c2SRolf Eike Beer */ 2411da177e4SLinus Torvalds int fastcall queue_delayed_work(struct workqueue_struct *wq, 24252bad64dSDavid Howells struct delayed_work *dwork, unsigned long delay) 2431da177e4SLinus Torvalds { 2441da177e4SLinus Torvalds int ret = 0; 24552bad64dSDavid Howells struct timer_list *timer = &dwork->timer; 24652bad64dSDavid Howells struct work_struct *work = &dwork->work; 24752bad64dSDavid Howells 24852bad64dSDavid Howells if (delay == 0) 24952bad64dSDavid Howells return queue_work(wq, work); 2501da177e4SLinus Torvalds 251a08727baSLinus Torvalds if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) { 2521da177e4SLinus Torvalds BUG_ON(timer_pending(timer)); 2531da177e4SLinus Torvalds BUG_ON(!list_empty(&work->entry)); 2541da177e4SLinus Torvalds 2551da177e4SLinus Torvalds /* This stores wq for the moment, for the timer_fn */ 256365970a1SDavid Howells set_wq_data(work, wq); 2571da177e4SLinus Torvalds timer->expires = jiffies + delay; 25852bad64dSDavid Howells timer->data = (unsigned long)dwork; 2591da177e4SLinus Torvalds timer->function = delayed_work_timer_fn; 2601da177e4SLinus Torvalds add_timer(timer); 2611da177e4SLinus Torvalds ret = 1; 2621da177e4SLinus Torvalds } 2631da177e4SLinus Torvalds return ret; 2641da177e4SLinus Torvalds } 265ae90dd5dSDave Jones EXPORT_SYMBOL_GPL(queue_delayed_work); 2661da177e4SLinus Torvalds 2670fcb78c2SRolf Eike Beer /** 2680fcb78c2SRolf Eike Beer * queue_delayed_work_on - queue work on specific CPU after delay 2690fcb78c2SRolf Eike Beer * @cpu: CPU number to execute work on 2700fcb78c2SRolf Eike Beer * @wq: workqueue to use 271af9997e4SRandy Dunlap * @dwork: work to queue 2720fcb78c2SRolf Eike Beer * @delay: number of jiffies to wait before queueing 2730fcb78c2SRolf Eike Beer * 274057647fcSAlan Stern * Returns 0 if @work was already on a queue, non-zero otherwise. 2750fcb78c2SRolf Eike Beer */ 2767a6bc1cdSVenkatesh Pallipadi int queue_delayed_work_on(int cpu, struct workqueue_struct *wq, 27752bad64dSDavid Howells struct delayed_work *dwork, unsigned long delay) 2787a6bc1cdSVenkatesh Pallipadi { 2797a6bc1cdSVenkatesh Pallipadi int ret = 0; 28052bad64dSDavid Howells struct timer_list *timer = &dwork->timer; 28152bad64dSDavid Howells struct work_struct *work = &dwork->work; 2827a6bc1cdSVenkatesh Pallipadi 283a08727baSLinus Torvalds if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) { 2847a6bc1cdSVenkatesh Pallipadi BUG_ON(timer_pending(timer)); 2857a6bc1cdSVenkatesh Pallipadi BUG_ON(!list_empty(&work->entry)); 2867a6bc1cdSVenkatesh Pallipadi 2877a6bc1cdSVenkatesh Pallipadi /* This stores wq for the moment, for the timer_fn */ 288365970a1SDavid Howells set_wq_data(work, wq); 2897a6bc1cdSVenkatesh Pallipadi timer->expires = jiffies + delay; 29052bad64dSDavid Howells timer->data = (unsigned long)dwork; 2917a6bc1cdSVenkatesh Pallipadi timer->function = delayed_work_timer_fn; 2927a6bc1cdSVenkatesh Pallipadi add_timer_on(timer, cpu); 2937a6bc1cdSVenkatesh Pallipadi ret = 1; 2947a6bc1cdSVenkatesh Pallipadi } 2957a6bc1cdSVenkatesh Pallipadi return ret; 2967a6bc1cdSVenkatesh Pallipadi } 297ae90dd5dSDave Jones EXPORT_SYMBOL_GPL(queue_delayed_work_on); 2981da177e4SLinus Torvalds 299858119e1SArjan van de Ven static void run_workqueue(struct cpu_workqueue_struct *cwq) 3001da177e4SLinus Torvalds { 3011da177e4SLinus Torvalds unsigned long flags; 3021da177e4SLinus Torvalds 3031da177e4SLinus Torvalds /* 3041da177e4SLinus Torvalds * Keep taking off work from the queue until 3051da177e4SLinus Torvalds * done. 3061da177e4SLinus Torvalds */ 3071da177e4SLinus Torvalds spin_lock_irqsave(&cwq->lock, flags); 3081da177e4SLinus Torvalds cwq->run_depth++; 3091da177e4SLinus Torvalds if (cwq->run_depth > 3) { 3101da177e4SLinus Torvalds /* morton gets to eat his hat */ 3111da177e4SLinus Torvalds printk("%s: recursion depth exceeded: %d\n", 3121da177e4SLinus Torvalds __FUNCTION__, cwq->run_depth); 3131da177e4SLinus Torvalds dump_stack(); 3141da177e4SLinus Torvalds } 3151da177e4SLinus Torvalds while (!list_empty(&cwq->worklist)) { 3161da177e4SLinus Torvalds struct work_struct *work = list_entry(cwq->worklist.next, 3171da177e4SLinus Torvalds struct work_struct, entry); 3186bb49e59SDavid Howells work_func_t f = work->func; 3191da177e4SLinus Torvalds 3201da177e4SLinus Torvalds list_del_init(cwq->worklist.next); 3211da177e4SLinus Torvalds spin_unlock_irqrestore(&cwq->lock, flags); 3221da177e4SLinus Torvalds 323365970a1SDavid Howells BUG_ON(get_wq_data(work) != cwq); 324a08727baSLinus Torvalds if (!test_bit(WORK_STRUCT_NOAUTOREL, work_data_bits(work))) 32565f27f38SDavid Howells work_release(work); 32665f27f38SDavid Howells f(work); 3271da177e4SLinus Torvalds 328d5abe669SPeter Zijlstra if (unlikely(in_atomic() || lockdep_depth(current) > 0)) { 329d5abe669SPeter Zijlstra printk(KERN_ERR "BUG: workqueue leaked lock or atomic: " 330d5abe669SPeter Zijlstra "%s/0x%08x/%d\n", 331d5abe669SPeter Zijlstra current->comm, preempt_count(), 332d5abe669SPeter Zijlstra current->pid); 333d5abe669SPeter Zijlstra printk(KERN_ERR " last function: "); 334d5abe669SPeter Zijlstra print_symbol("%s\n", (unsigned long)f); 335d5abe669SPeter Zijlstra debug_show_held_locks(current); 336d5abe669SPeter Zijlstra dump_stack(); 337d5abe669SPeter Zijlstra } 338d5abe669SPeter Zijlstra 3391da177e4SLinus Torvalds spin_lock_irqsave(&cwq->lock, flags); 3401da177e4SLinus Torvalds cwq->remove_sequence++; 3411da177e4SLinus Torvalds wake_up(&cwq->work_done); 3421da177e4SLinus Torvalds } 3431da177e4SLinus Torvalds cwq->run_depth--; 3441da177e4SLinus Torvalds spin_unlock_irqrestore(&cwq->lock, flags); 3451da177e4SLinus Torvalds } 3461da177e4SLinus Torvalds 3471da177e4SLinus Torvalds static int worker_thread(void *__cwq) 3481da177e4SLinus Torvalds { 3491da177e4SLinus Torvalds struct cpu_workqueue_struct *cwq = __cwq; 3501da177e4SLinus Torvalds DECLARE_WAITQUEUE(wait, current); 3511da177e4SLinus Torvalds struct k_sigaction sa; 3521da177e4SLinus Torvalds sigset_t blocked; 3531da177e4SLinus Torvalds 354341a5958SRafael J. Wysocki if (!cwq->freezeable) 3551da177e4SLinus Torvalds current->flags |= PF_NOFREEZE; 3561da177e4SLinus Torvalds 3571da177e4SLinus Torvalds set_user_nice(current, -5); 3581da177e4SLinus Torvalds 3591da177e4SLinus Torvalds /* Block and flush all signals */ 3601da177e4SLinus Torvalds sigfillset(&blocked); 3611da177e4SLinus Torvalds sigprocmask(SIG_BLOCK, &blocked, NULL); 3621da177e4SLinus Torvalds flush_signals(current); 3631da177e4SLinus Torvalds 36446934023SChristoph Lameter /* 36546934023SChristoph Lameter * We inherited MPOL_INTERLEAVE from the booting kernel. 36646934023SChristoph Lameter * Set MPOL_DEFAULT to insure node local allocations. 36746934023SChristoph Lameter */ 36846934023SChristoph Lameter numa_default_policy(); 36946934023SChristoph Lameter 3701da177e4SLinus Torvalds /* SIG_IGN makes children autoreap: see do_notify_parent(). */ 3711da177e4SLinus Torvalds sa.sa.sa_handler = SIG_IGN; 3721da177e4SLinus Torvalds sa.sa.sa_flags = 0; 3731da177e4SLinus Torvalds siginitset(&sa.sa.sa_mask, sigmask(SIGCHLD)); 3741da177e4SLinus Torvalds do_sigaction(SIGCHLD, &sa, (struct k_sigaction *)0); 3751da177e4SLinus Torvalds 3761da177e4SLinus Torvalds set_current_state(TASK_INTERRUPTIBLE); 3771da177e4SLinus Torvalds while (!kthread_should_stop()) { 378341a5958SRafael J. Wysocki if (cwq->freezeable) 379341a5958SRafael J. Wysocki try_to_freeze(); 380341a5958SRafael J. Wysocki 3811da177e4SLinus Torvalds add_wait_queue(&cwq->more_work, &wait); 3821da177e4SLinus Torvalds if (list_empty(&cwq->worklist)) 3831da177e4SLinus Torvalds schedule(); 3841da177e4SLinus Torvalds else 3851da177e4SLinus Torvalds __set_current_state(TASK_RUNNING); 3861da177e4SLinus Torvalds remove_wait_queue(&cwq->more_work, &wait); 3871da177e4SLinus Torvalds 3881da177e4SLinus Torvalds if (!list_empty(&cwq->worklist)) 3891da177e4SLinus Torvalds run_workqueue(cwq); 3901da177e4SLinus Torvalds set_current_state(TASK_INTERRUPTIBLE); 3911da177e4SLinus Torvalds } 3921da177e4SLinus Torvalds __set_current_state(TASK_RUNNING); 3931da177e4SLinus Torvalds return 0; 3941da177e4SLinus Torvalds } 3951da177e4SLinus Torvalds 3961da177e4SLinus Torvalds static void flush_cpu_workqueue(struct cpu_workqueue_struct *cwq) 3971da177e4SLinus Torvalds { 3981da177e4SLinus Torvalds if (cwq->thread == current) { 3991da177e4SLinus Torvalds /* 4001da177e4SLinus Torvalds * Probably keventd trying to flush its own queue. So simply run 4011da177e4SLinus Torvalds * it by hand rather than deadlocking. 4021da177e4SLinus Torvalds */ 4031da177e4SLinus Torvalds run_workqueue(cwq); 4041da177e4SLinus Torvalds } else { 4051da177e4SLinus Torvalds DEFINE_WAIT(wait); 4061da177e4SLinus Torvalds long sequence_needed; 4071da177e4SLinus Torvalds 4081da177e4SLinus Torvalds spin_lock_irq(&cwq->lock); 4091da177e4SLinus Torvalds sequence_needed = cwq->insert_sequence; 4101da177e4SLinus Torvalds 4111da177e4SLinus Torvalds while (sequence_needed - cwq->remove_sequence > 0) { 4121da177e4SLinus Torvalds prepare_to_wait(&cwq->work_done, &wait, 4131da177e4SLinus Torvalds TASK_UNINTERRUPTIBLE); 4141da177e4SLinus Torvalds spin_unlock_irq(&cwq->lock); 4151da177e4SLinus Torvalds schedule(); 4161da177e4SLinus Torvalds spin_lock_irq(&cwq->lock); 4171da177e4SLinus Torvalds } 4181da177e4SLinus Torvalds finish_wait(&cwq->work_done, &wait); 4191da177e4SLinus Torvalds spin_unlock_irq(&cwq->lock); 4201da177e4SLinus Torvalds } 4211da177e4SLinus Torvalds } 4221da177e4SLinus Torvalds 4230fcb78c2SRolf Eike Beer /** 4241da177e4SLinus Torvalds * flush_workqueue - ensure that any scheduled work has run to completion. 4250fcb78c2SRolf Eike Beer * @wq: workqueue to flush 4261da177e4SLinus Torvalds * 4271da177e4SLinus Torvalds * Forces execution of the workqueue and blocks until its completion. 4281da177e4SLinus Torvalds * This is typically used in driver shutdown handlers. 4291da177e4SLinus Torvalds * 4301da177e4SLinus Torvalds * This function will sample each workqueue's current insert_sequence number and 4311da177e4SLinus Torvalds * will sleep until the head sequence is greater than or equal to that. This 4321da177e4SLinus Torvalds * means that we sleep until all works which were queued on entry have been 4331da177e4SLinus Torvalds * handled, but we are not livelocked by new incoming ones. 4341da177e4SLinus Torvalds * 4351da177e4SLinus Torvalds * This function used to run the workqueues itself. Now we just wait for the 4361da177e4SLinus Torvalds * helper threads to do it. 4371da177e4SLinus Torvalds */ 4381da177e4SLinus Torvalds void fastcall flush_workqueue(struct workqueue_struct *wq) 4391da177e4SLinus Torvalds { 4401da177e4SLinus Torvalds might_sleep(); 4411da177e4SLinus Torvalds 4421da177e4SLinus Torvalds if (is_single_threaded(wq)) { 443bce61dd4SBen Collins /* Always use first cpu's area. */ 444f756d5e2SNathan Lynch flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, singlethread_cpu)); 4451da177e4SLinus Torvalds } else { 4461da177e4SLinus Torvalds int cpu; 4471da177e4SLinus Torvalds 4489b41ea72SAndrew Morton mutex_lock(&workqueue_mutex); 4491da177e4SLinus Torvalds for_each_online_cpu(cpu) 45089ada679SChristoph Lameter flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu)); 4519b41ea72SAndrew Morton mutex_unlock(&workqueue_mutex); 4521da177e4SLinus Torvalds } 4531da177e4SLinus Torvalds } 454ae90dd5dSDave Jones EXPORT_SYMBOL_GPL(flush_workqueue); 4551da177e4SLinus Torvalds 4561da177e4SLinus Torvalds static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq, 457341a5958SRafael J. Wysocki int cpu, int freezeable) 4581da177e4SLinus Torvalds { 45989ada679SChristoph Lameter struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); 4601da177e4SLinus Torvalds struct task_struct *p; 4611da177e4SLinus Torvalds 4621da177e4SLinus Torvalds spin_lock_init(&cwq->lock); 4631da177e4SLinus Torvalds cwq->wq = wq; 4641da177e4SLinus Torvalds cwq->thread = NULL; 4651da177e4SLinus Torvalds cwq->insert_sequence = 0; 4661da177e4SLinus Torvalds cwq->remove_sequence = 0; 467341a5958SRafael J. Wysocki cwq->freezeable = freezeable; 4681da177e4SLinus Torvalds INIT_LIST_HEAD(&cwq->worklist); 4691da177e4SLinus Torvalds init_waitqueue_head(&cwq->more_work); 4701da177e4SLinus Torvalds init_waitqueue_head(&cwq->work_done); 4711da177e4SLinus Torvalds 4721da177e4SLinus Torvalds if (is_single_threaded(wq)) 4731da177e4SLinus Torvalds p = kthread_create(worker_thread, cwq, "%s", wq->name); 4741da177e4SLinus Torvalds else 4751da177e4SLinus Torvalds p = kthread_create(worker_thread, cwq, "%s/%d", wq->name, cpu); 4761da177e4SLinus Torvalds if (IS_ERR(p)) 4771da177e4SLinus Torvalds return NULL; 4781da177e4SLinus Torvalds cwq->thread = p; 4791da177e4SLinus Torvalds return p; 4801da177e4SLinus Torvalds } 4811da177e4SLinus Torvalds 4821da177e4SLinus Torvalds struct workqueue_struct *__create_workqueue(const char *name, 483341a5958SRafael J. Wysocki int singlethread, int freezeable) 4841da177e4SLinus Torvalds { 4851da177e4SLinus Torvalds int cpu, destroy = 0; 4861da177e4SLinus Torvalds struct workqueue_struct *wq; 4871da177e4SLinus Torvalds struct task_struct *p; 4881da177e4SLinus Torvalds 489dd392710SPekka J Enberg wq = kzalloc(sizeof(*wq), GFP_KERNEL); 4901da177e4SLinus Torvalds if (!wq) 4911da177e4SLinus Torvalds return NULL; 4921da177e4SLinus Torvalds 49389ada679SChristoph Lameter wq->cpu_wq = alloc_percpu(struct cpu_workqueue_struct); 494676121fcSBen Collins if (!wq->cpu_wq) { 495676121fcSBen Collins kfree(wq); 496676121fcSBen Collins return NULL; 497676121fcSBen Collins } 498676121fcSBen Collins 4991da177e4SLinus Torvalds wq->name = name; 5009b41ea72SAndrew Morton mutex_lock(&workqueue_mutex); 5011da177e4SLinus Torvalds if (singlethread) { 5021da177e4SLinus Torvalds INIT_LIST_HEAD(&wq->list); 503341a5958SRafael J. Wysocki p = create_workqueue_thread(wq, singlethread_cpu, freezeable); 5041da177e4SLinus Torvalds if (!p) 5051da177e4SLinus Torvalds destroy = 1; 5061da177e4SLinus Torvalds else 5071da177e4SLinus Torvalds wake_up_process(p); 5081da177e4SLinus Torvalds } else { 5091da177e4SLinus Torvalds list_add(&wq->list, &workqueues); 5101da177e4SLinus Torvalds for_each_online_cpu(cpu) { 511341a5958SRafael J. Wysocki p = create_workqueue_thread(wq, cpu, freezeable); 5121da177e4SLinus Torvalds if (p) { 5131da177e4SLinus Torvalds kthread_bind(p, cpu); 5141da177e4SLinus Torvalds wake_up_process(p); 5151da177e4SLinus Torvalds } else 5161da177e4SLinus Torvalds destroy = 1; 5171da177e4SLinus Torvalds } 5181da177e4SLinus Torvalds } 5199b41ea72SAndrew Morton mutex_unlock(&workqueue_mutex); 5201da177e4SLinus Torvalds 5211da177e4SLinus Torvalds /* 5221da177e4SLinus Torvalds * Was there any error during startup? If yes then clean up: 5231da177e4SLinus Torvalds */ 5241da177e4SLinus Torvalds if (destroy) { 5251da177e4SLinus Torvalds destroy_workqueue(wq); 5261da177e4SLinus Torvalds wq = NULL; 5271da177e4SLinus Torvalds } 5281da177e4SLinus Torvalds return wq; 5291da177e4SLinus Torvalds } 530ae90dd5dSDave Jones EXPORT_SYMBOL_GPL(__create_workqueue); 5311da177e4SLinus Torvalds 5321da177e4SLinus Torvalds static void cleanup_workqueue_thread(struct workqueue_struct *wq, int cpu) 5331da177e4SLinus Torvalds { 5341da177e4SLinus Torvalds struct cpu_workqueue_struct *cwq; 5351da177e4SLinus Torvalds unsigned long flags; 5361da177e4SLinus Torvalds struct task_struct *p; 5371da177e4SLinus Torvalds 53889ada679SChristoph Lameter cwq = per_cpu_ptr(wq->cpu_wq, cpu); 5391da177e4SLinus Torvalds spin_lock_irqsave(&cwq->lock, flags); 5401da177e4SLinus Torvalds p = cwq->thread; 5411da177e4SLinus Torvalds cwq->thread = NULL; 5421da177e4SLinus Torvalds spin_unlock_irqrestore(&cwq->lock, flags); 5431da177e4SLinus Torvalds if (p) 5441da177e4SLinus Torvalds kthread_stop(p); 5451da177e4SLinus Torvalds } 5461da177e4SLinus Torvalds 5470fcb78c2SRolf Eike Beer /** 5480fcb78c2SRolf Eike Beer * destroy_workqueue - safely terminate a workqueue 5490fcb78c2SRolf Eike Beer * @wq: target workqueue 5500fcb78c2SRolf Eike Beer * 5510fcb78c2SRolf Eike Beer * Safely destroy a workqueue. All work currently pending will be done first. 5520fcb78c2SRolf Eike Beer */ 5531da177e4SLinus Torvalds void destroy_workqueue(struct workqueue_struct *wq) 5541da177e4SLinus Torvalds { 5551da177e4SLinus Torvalds int cpu; 5561da177e4SLinus Torvalds 5571da177e4SLinus Torvalds flush_workqueue(wq); 5581da177e4SLinus Torvalds 5591da177e4SLinus Torvalds /* We don't need the distraction of CPUs appearing and vanishing. */ 5609b41ea72SAndrew Morton mutex_lock(&workqueue_mutex); 5611da177e4SLinus Torvalds if (is_single_threaded(wq)) 562f756d5e2SNathan Lynch cleanup_workqueue_thread(wq, singlethread_cpu); 5631da177e4SLinus Torvalds else { 5641da177e4SLinus Torvalds for_each_online_cpu(cpu) 5651da177e4SLinus Torvalds cleanup_workqueue_thread(wq, cpu); 5661da177e4SLinus Torvalds list_del(&wq->list); 5671da177e4SLinus Torvalds } 5689b41ea72SAndrew Morton mutex_unlock(&workqueue_mutex); 56989ada679SChristoph Lameter free_percpu(wq->cpu_wq); 5701da177e4SLinus Torvalds kfree(wq); 5711da177e4SLinus Torvalds } 572ae90dd5dSDave Jones EXPORT_SYMBOL_GPL(destroy_workqueue); 5731da177e4SLinus Torvalds 5741da177e4SLinus Torvalds static struct workqueue_struct *keventd_wq; 5751da177e4SLinus Torvalds 5760fcb78c2SRolf Eike Beer /** 5770fcb78c2SRolf Eike Beer * schedule_work - put work task in global workqueue 5780fcb78c2SRolf Eike Beer * @work: job to be done 5790fcb78c2SRolf Eike Beer * 5800fcb78c2SRolf Eike Beer * This puts a job in the kernel-global workqueue. 5810fcb78c2SRolf Eike Beer */ 5821da177e4SLinus Torvalds int fastcall schedule_work(struct work_struct *work) 5831da177e4SLinus Torvalds { 5841da177e4SLinus Torvalds return queue_work(keventd_wq, work); 5851da177e4SLinus Torvalds } 586ae90dd5dSDave Jones EXPORT_SYMBOL(schedule_work); 5871da177e4SLinus Torvalds 5880fcb78c2SRolf Eike Beer /** 5890fcb78c2SRolf Eike Beer * schedule_delayed_work - put work task in global workqueue after delay 59052bad64dSDavid Howells * @dwork: job to be done 59152bad64dSDavid Howells * @delay: number of jiffies to wait or 0 for immediate execution 5920fcb78c2SRolf Eike Beer * 5930fcb78c2SRolf Eike Beer * After waiting for a given time this puts a job in the kernel-global 5940fcb78c2SRolf Eike Beer * workqueue. 5950fcb78c2SRolf Eike Beer */ 59652bad64dSDavid Howells int fastcall schedule_delayed_work(struct delayed_work *dwork, unsigned long delay) 5971da177e4SLinus Torvalds { 59852bad64dSDavid Howells return queue_delayed_work(keventd_wq, dwork, delay); 5991da177e4SLinus Torvalds } 600ae90dd5dSDave Jones EXPORT_SYMBOL(schedule_delayed_work); 6011da177e4SLinus Torvalds 6020fcb78c2SRolf Eike Beer /** 6030fcb78c2SRolf Eike Beer * schedule_delayed_work_on - queue work in global workqueue on CPU after delay 6040fcb78c2SRolf Eike Beer * @cpu: cpu to use 60552bad64dSDavid Howells * @dwork: job to be done 6060fcb78c2SRolf Eike Beer * @delay: number of jiffies to wait 6070fcb78c2SRolf Eike Beer * 6080fcb78c2SRolf Eike Beer * After waiting for a given time this puts a job in the kernel-global 6090fcb78c2SRolf Eike Beer * workqueue on the specified CPU. 6100fcb78c2SRolf Eike Beer */ 6111da177e4SLinus Torvalds int schedule_delayed_work_on(int cpu, 61252bad64dSDavid Howells struct delayed_work *dwork, unsigned long delay) 6131da177e4SLinus Torvalds { 61452bad64dSDavid Howells return queue_delayed_work_on(cpu, keventd_wq, dwork, delay); 6151da177e4SLinus Torvalds } 616ae90dd5dSDave Jones EXPORT_SYMBOL(schedule_delayed_work_on); 6171da177e4SLinus Torvalds 618b6136773SAndrew Morton /** 619b6136773SAndrew Morton * schedule_on_each_cpu - call a function on each online CPU from keventd 620b6136773SAndrew Morton * @func: the function to call 621b6136773SAndrew Morton * 622b6136773SAndrew Morton * Returns zero on success. 623b6136773SAndrew Morton * Returns -ve errno on failure. 624b6136773SAndrew Morton * 625b6136773SAndrew Morton * Appears to be racy against CPU hotplug. 626b6136773SAndrew Morton * 627b6136773SAndrew Morton * schedule_on_each_cpu() is very slow. 628b6136773SAndrew Morton */ 62965f27f38SDavid Howells int schedule_on_each_cpu(work_func_t func) 63015316ba8SChristoph Lameter { 63115316ba8SChristoph Lameter int cpu; 632b6136773SAndrew Morton struct work_struct *works; 63315316ba8SChristoph Lameter 634b6136773SAndrew Morton works = alloc_percpu(struct work_struct); 635b6136773SAndrew Morton if (!works) 63615316ba8SChristoph Lameter return -ENOMEM; 637b6136773SAndrew Morton 6389b41ea72SAndrew Morton mutex_lock(&workqueue_mutex); 63915316ba8SChristoph Lameter for_each_online_cpu(cpu) { 6409bfb1839SIngo Molnar struct work_struct *work = per_cpu_ptr(works, cpu); 6419bfb1839SIngo Molnar 6429bfb1839SIngo Molnar INIT_WORK(work, func); 6439bfb1839SIngo Molnar set_bit(WORK_STRUCT_PENDING, work_data_bits(work)); 6449bfb1839SIngo Molnar __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu), work); 64515316ba8SChristoph Lameter } 6469b41ea72SAndrew Morton mutex_unlock(&workqueue_mutex); 64715316ba8SChristoph Lameter flush_workqueue(keventd_wq); 648b6136773SAndrew Morton free_percpu(works); 64915316ba8SChristoph Lameter return 0; 65015316ba8SChristoph Lameter } 65115316ba8SChristoph Lameter 6521da177e4SLinus Torvalds void flush_scheduled_work(void) 6531da177e4SLinus Torvalds { 6541da177e4SLinus Torvalds flush_workqueue(keventd_wq); 6551da177e4SLinus Torvalds } 656ae90dd5dSDave Jones EXPORT_SYMBOL(flush_scheduled_work); 6571da177e4SLinus Torvalds 6581da177e4SLinus Torvalds /** 6591da177e4SLinus Torvalds * cancel_rearming_delayed_workqueue - reliably kill off a delayed 6601da177e4SLinus Torvalds * work whose handler rearms the delayed work. 6611da177e4SLinus Torvalds * @wq: the controlling workqueue structure 66252bad64dSDavid Howells * @dwork: the delayed work struct 6631da177e4SLinus Torvalds */ 66481ddef77SJames Bottomley void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq, 66552bad64dSDavid Howells struct delayed_work *dwork) 6661da177e4SLinus Torvalds { 66752bad64dSDavid Howells while (!cancel_delayed_work(dwork)) 6681da177e4SLinus Torvalds flush_workqueue(wq); 6691da177e4SLinus Torvalds } 67081ddef77SJames Bottomley EXPORT_SYMBOL(cancel_rearming_delayed_workqueue); 6711da177e4SLinus Torvalds 6721da177e4SLinus Torvalds /** 6731da177e4SLinus Torvalds * cancel_rearming_delayed_work - reliably kill off a delayed keventd 6741da177e4SLinus Torvalds * work whose handler rearms the delayed work. 67552bad64dSDavid Howells * @dwork: the delayed work struct 6761da177e4SLinus Torvalds */ 67752bad64dSDavid Howells void cancel_rearming_delayed_work(struct delayed_work *dwork) 6781da177e4SLinus Torvalds { 67952bad64dSDavid Howells cancel_rearming_delayed_workqueue(keventd_wq, dwork); 6801da177e4SLinus Torvalds } 6811da177e4SLinus Torvalds EXPORT_SYMBOL(cancel_rearming_delayed_work); 6821da177e4SLinus Torvalds 6831fa44ecaSJames Bottomley /** 6841fa44ecaSJames Bottomley * execute_in_process_context - reliably execute the routine with user context 6851fa44ecaSJames Bottomley * @fn: the function to execute 6861fa44ecaSJames Bottomley * @ew: guaranteed storage for the execute work structure (must 6871fa44ecaSJames Bottomley * be available when the work executes) 6881fa44ecaSJames Bottomley * 6891fa44ecaSJames Bottomley * Executes the function immediately if process context is available, 6901fa44ecaSJames Bottomley * otherwise schedules the function for delayed execution. 6911fa44ecaSJames Bottomley * 6921fa44ecaSJames Bottomley * Returns: 0 - function was executed 6931fa44ecaSJames Bottomley * 1 - function was scheduled for execution 6941fa44ecaSJames Bottomley */ 69565f27f38SDavid Howells int execute_in_process_context(work_func_t fn, struct execute_work *ew) 6961fa44ecaSJames Bottomley { 6971fa44ecaSJames Bottomley if (!in_interrupt()) { 69865f27f38SDavid Howells fn(&ew->work); 6991fa44ecaSJames Bottomley return 0; 7001fa44ecaSJames Bottomley } 7011fa44ecaSJames Bottomley 70265f27f38SDavid Howells INIT_WORK(&ew->work, fn); 7031fa44ecaSJames Bottomley schedule_work(&ew->work); 7041fa44ecaSJames Bottomley 7051fa44ecaSJames Bottomley return 1; 7061fa44ecaSJames Bottomley } 7071fa44ecaSJames Bottomley EXPORT_SYMBOL_GPL(execute_in_process_context); 7081fa44ecaSJames Bottomley 7091da177e4SLinus Torvalds int keventd_up(void) 7101da177e4SLinus Torvalds { 7111da177e4SLinus Torvalds return keventd_wq != NULL; 7121da177e4SLinus Torvalds } 7131da177e4SLinus Torvalds 7141da177e4SLinus Torvalds int current_is_keventd(void) 7151da177e4SLinus Torvalds { 7161da177e4SLinus Torvalds struct cpu_workqueue_struct *cwq; 7171da177e4SLinus Torvalds int cpu = smp_processor_id(); /* preempt-safe: keventd is per-cpu */ 7181da177e4SLinus Torvalds int ret = 0; 7191da177e4SLinus Torvalds 7201da177e4SLinus Torvalds BUG_ON(!keventd_wq); 7211da177e4SLinus Torvalds 72289ada679SChristoph Lameter cwq = per_cpu_ptr(keventd_wq->cpu_wq, cpu); 7231da177e4SLinus Torvalds if (current == cwq->thread) 7241da177e4SLinus Torvalds ret = 1; 7251da177e4SLinus Torvalds 7261da177e4SLinus Torvalds return ret; 7271da177e4SLinus Torvalds 7281da177e4SLinus Torvalds } 7291da177e4SLinus Torvalds 7301da177e4SLinus Torvalds /* Take the work from this (downed) CPU. */ 7311da177e4SLinus Torvalds static void take_over_work(struct workqueue_struct *wq, unsigned int cpu) 7321da177e4SLinus Torvalds { 73389ada679SChristoph Lameter struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); 734626ab0e6SOleg Nesterov struct list_head list; 7351da177e4SLinus Torvalds struct work_struct *work; 7361da177e4SLinus Torvalds 7371da177e4SLinus Torvalds spin_lock_irq(&cwq->lock); 738626ab0e6SOleg Nesterov list_replace_init(&cwq->worklist, &list); 7391da177e4SLinus Torvalds 7401da177e4SLinus Torvalds while (!list_empty(&list)) { 7411da177e4SLinus Torvalds printk("Taking work for %s\n", wq->name); 7421da177e4SLinus Torvalds work = list_entry(list.next,struct work_struct,entry); 7431da177e4SLinus Torvalds list_del(&work->entry); 74489ada679SChristoph Lameter __queue_work(per_cpu_ptr(wq->cpu_wq, smp_processor_id()), work); 7451da177e4SLinus Torvalds } 7461da177e4SLinus Torvalds spin_unlock_irq(&cwq->lock); 7471da177e4SLinus Torvalds } 7481da177e4SLinus Torvalds 7491da177e4SLinus Torvalds /* We're holding the cpucontrol mutex here */ 7509c7b216dSChandra Seetharaman static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, 7511da177e4SLinus Torvalds unsigned long action, 7521da177e4SLinus Torvalds void *hcpu) 7531da177e4SLinus Torvalds { 7541da177e4SLinus Torvalds unsigned int hotcpu = (unsigned long)hcpu; 7551da177e4SLinus Torvalds struct workqueue_struct *wq; 7561da177e4SLinus Torvalds 7571da177e4SLinus Torvalds switch (action) { 7581da177e4SLinus Torvalds case CPU_UP_PREPARE: 7599b41ea72SAndrew Morton mutex_lock(&workqueue_mutex); 7601da177e4SLinus Torvalds /* Create a new workqueue thread for it. */ 7611da177e4SLinus Torvalds list_for_each_entry(wq, &workqueues, list) { 762341a5958SRafael J. Wysocki if (!create_workqueue_thread(wq, hotcpu, 0)) { 7631da177e4SLinus Torvalds printk("workqueue for %i failed\n", hotcpu); 7641da177e4SLinus Torvalds return NOTIFY_BAD; 7651da177e4SLinus Torvalds } 7661da177e4SLinus Torvalds } 7671da177e4SLinus Torvalds break; 7681da177e4SLinus Torvalds 7691da177e4SLinus Torvalds case CPU_ONLINE: 7701da177e4SLinus Torvalds /* Kick off worker threads. */ 7711da177e4SLinus Torvalds list_for_each_entry(wq, &workqueues, list) { 77289ada679SChristoph Lameter struct cpu_workqueue_struct *cwq; 77389ada679SChristoph Lameter 77489ada679SChristoph Lameter cwq = per_cpu_ptr(wq->cpu_wq, hotcpu); 77589ada679SChristoph Lameter kthread_bind(cwq->thread, hotcpu); 77689ada679SChristoph Lameter wake_up_process(cwq->thread); 7771da177e4SLinus Torvalds } 7789b41ea72SAndrew Morton mutex_unlock(&workqueue_mutex); 7791da177e4SLinus Torvalds break; 7801da177e4SLinus Torvalds 7811da177e4SLinus Torvalds case CPU_UP_CANCELED: 7821da177e4SLinus Torvalds list_for_each_entry(wq, &workqueues, list) { 783fc75cdfaSHeiko Carstens if (!per_cpu_ptr(wq->cpu_wq, hotcpu)->thread) 784fc75cdfaSHeiko Carstens continue; 7851da177e4SLinus Torvalds /* Unbind so it can run. */ 78689ada679SChristoph Lameter kthread_bind(per_cpu_ptr(wq->cpu_wq, hotcpu)->thread, 787a4c4af7cSHeiko Carstens any_online_cpu(cpu_online_map)); 7881da177e4SLinus Torvalds cleanup_workqueue_thread(wq, hotcpu); 7891da177e4SLinus Torvalds } 7909b41ea72SAndrew Morton mutex_unlock(&workqueue_mutex); 7919b41ea72SAndrew Morton break; 7929b41ea72SAndrew Morton 7939b41ea72SAndrew Morton case CPU_DOWN_PREPARE: 7949b41ea72SAndrew Morton mutex_lock(&workqueue_mutex); 7959b41ea72SAndrew Morton break; 7969b41ea72SAndrew Morton 7979b41ea72SAndrew Morton case CPU_DOWN_FAILED: 7989b41ea72SAndrew Morton mutex_unlock(&workqueue_mutex); 7991da177e4SLinus Torvalds break; 8001da177e4SLinus Torvalds 8011da177e4SLinus Torvalds case CPU_DEAD: 8021da177e4SLinus Torvalds list_for_each_entry(wq, &workqueues, list) 8031da177e4SLinus Torvalds cleanup_workqueue_thread(wq, hotcpu); 8041da177e4SLinus Torvalds list_for_each_entry(wq, &workqueues, list) 8051da177e4SLinus Torvalds take_over_work(wq, hotcpu); 8069b41ea72SAndrew Morton mutex_unlock(&workqueue_mutex); 8071da177e4SLinus Torvalds break; 8081da177e4SLinus Torvalds } 8091da177e4SLinus Torvalds 8101da177e4SLinus Torvalds return NOTIFY_OK; 8111da177e4SLinus Torvalds } 8121da177e4SLinus Torvalds 8131da177e4SLinus Torvalds void init_workqueues(void) 8141da177e4SLinus Torvalds { 815f756d5e2SNathan Lynch singlethread_cpu = first_cpu(cpu_possible_map); 8161da177e4SLinus Torvalds hotcpu_notifier(workqueue_cpu_callback, 0); 8171da177e4SLinus Torvalds keventd_wq = create_workqueue("events"); 8181da177e4SLinus Torvalds BUG_ON(!keventd_wq); 8191da177e4SLinus Torvalds } 8201da177e4SLinus Torvalds 821