/* * linux/kernel/workqueue.c * * Generic mechanism for defining kernel helper threads for running * arbitrary tasks in process context. * * Started by Ingo Molnar, Copyright (C) 2002 * * Derived from the taskqueue/keventd code by: * * David Woodhouse <dwmw2@infradead.org> * Andrew Morton <andrewm@uow.edu.au> * Kai Petzke <wpp@marie.physik.tu-berlin.de> * Theodore Ts'o <tytso@mit.edu> * * Made to use alloc_percpu by Christoph Lameter <clameter@sgi.com>. */ #include <linux/module.h>#include <linux/kernel.h>#include <linux/sched.h>#include <linux/init.h>#include <linux/signal.h>#include <linux/completion.h>#include <linux/workqueue.h>#include <linux/slab.h>#include <linux/cpu.h>#include <linux/notifier.h>#include <linux/kthread.h>#include <linux/hardirq.h>#include <linux/mempolicy.h> /* * The per-CPU workqueue (if single thread, we always use the first * possible cpu). * * The sequence counters are for flush_scheduled_work(). It wants to wait * until all currently-scheduled works are completed, but it doesn't * want to be livelocked by new, incoming ones. So it waits until * remove_sequence is >= the insert_sequence which pertained when * flush_scheduled_work() was called. */struct cpu_workqueue_struct { spinlock_t lock; long remove_sequence; /* Least-recently added (next to run) */ long insert_sequence; /* Next to add */ struct list_head worklist; wait_queue_head_t more_work; wait_queue_head_t work_done; struct workqueue_struct *wq; struct task_struct *thread; int run_depth; /* Detect run_workqueue() recursion depth */} ____cacheline_aligned; /* * The externally visible workqueue abstraction is an array of * per-CPU workqueues: */struct workqueue_struct { struct cpu_workqueue_struct *cpu_wq; const char *name; struct list_head list; /* Empty if single thread */}; /* All the per-cpu workqueues on the system, for hotplug cpu to add/remove threads to each one as cpus come/go. */static DEFINE_MUTEX(workqueue_mutex);static LIST_HEAD(workqueues); static int singlethread_cpu; /* If it's single threaded, it isn't in the list of workqueues. */static inline int is_single_threaded(struct workqueue_struct *wq){ return list_empty(&wq->list);} /* Preempt must be disabled. */static void __queue_work(struct cpu_workqueue_struct *cwq, struct work_struct *work){ unsigned long flags; spin_lock_irqsave(&cwq->lock, flags); work->wq_data = cwq; list_add_tail(&work->entry, &cwq->worklist); cwq->insert_sequence++; wake_up(&cwq->more_work); spin_unlock_irqrestore(&cwq->lock, flags);} /** * queue_work - queue work on a workqueue * @wq: workqueue to use * @work: work to queue * * Returns 0 if @work was already on a queue, non-zero otherwise. * * We queue the work to the CPU it was submitted, but there is no * guarantee that it will be processed by that CPU. */int fastcall queue_work(struct workqueue_struct *wq, struct work_struct *work){ int ret = 0, cpu = get_cpu(); if (!test_and_set_bit(0, &work->pending)) { if (unlikely(is_single_threaded(wq))) cpu = singlethread_cpu; BUG_ON(!list_empty(&work->entry)); __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work); ret = 1; } put_cpu(); return ret;}EXPORT_SYMBOL_GPL(queue_work); static void delayed_work_timer_fn(unsigned long __data){ struct delayed_work *dwork = (struct delayed_work *)__data; struct workqueue_struct *wq = dwork->work.wq_data; int cpu = smp_processor_id(); if (unlikely(is_single_threaded(wq))) cpu = singlethread_cpu; __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), &dwork->work);} /** * queue_delayed_work - queue work on a workqueue after delay * @wq: workqueue to use * @work: delayable work to queue * @delay: number of jiffies to wait before queueing * * Returns 0 if @work was already on a queue, non-zero otherwise. */int fastcall queue_delayed_work(struct workqueue_struct *wq, struct delayed_work *dwork, unsigned long delay){ int ret = 0; struct timer_list *timer = &dwork->timer; struct work_struct *work = &dwork->work; if (delay == 0) return queue_work(wq, work); if (!test_and_set_bit(0, &work->pending)) { BUG_ON(timer_pending(timer)); BUG_ON(!list_empty(&work->entry)); /* This stores wq for the moment, for the timer_fn */ work->wq_data = wq; timer->expires = jiffies + delay; timer->data = (unsigned long)dwork; timer->function = delayed_work_timer_fn; add_timer(timer); ret = 1; } return ret;}EXPORT_SYMBOL_GPL(queue_delayed_work); /** * queue_delayed_work_on - queue work on specific CPU after delay * @cpu: CPU number to execute work on * @wq: workqueue to use * @work: work to queue * @delay: number of jiffies to wait before queueing * * Returns 0 if @work was already on a queue, non-zero otherwise. */int queue_delayed_work_on(int cpu, struct workqueue_struct *wq, struct delayed_work *dwork, unsigned long delay){ int ret = 0; struct timer_list *timer = &dwork->timer; struct work_struct *work = &dwork->work; if (!test_and_set_bit(0, &work->pending)) { BUG_ON(timer_pending(timer)); BUG_ON(!list_empty(&work->entry)); /* This stores wq for the moment, for the timer_fn */ work->wq_data = wq; timer->expires = jiffies + delay; timer->data = (unsigned long)dwork; timer->function = delayed_work_timer_fn; add_timer_on(timer, cpu); ret = 1; } return ret;}EXPORT_SYMBOL_GPL(queue_delayed_work_on); static void run_workqueue(struct cpu_workqueue_struct *cwq){ unsigned long flags; /* * Keep taking off work from the queue until * done. */ spin_lock_irqsave(&cwq->lock, flags); cwq->run_depth++; if (cwq->run_depth > 3) { /* morton gets to eat his hat */ printk("%s: recursion depth exceeded: %d\n", __FUNCTION__, cwq->run_depth); dump_stack(); } while (!list_empty(&cwq->worklist)) { struct work_struct *work = list_entry(cwq->worklist.next, struct work_struct, entry); work_func_t f = work->func; void *data = work->data; list_del_init(cwq->worklist.next); spin_unlock_irqrestore(&cwq->lock, flags); BUG_ON(work->wq_data != cwq); clear_bit(0, &work->pending); f(data); spin_lock_irqsave(&cwq->lock, flags); cwq->remove_sequence++; wake_up(&cwq->work_done); } cwq->run_depth--; spin_unlock_irqrestore(&cwq->lock, flags);} static int worker_thread(void *__cwq){ struct cpu_workqueue_struct *cwq = __cwq; DECLARE_WAITQUEUE(wait, current); struct k_sigaction sa; sigset_t blocked; current->flags |= PF_NOFREEZE; set_user_nice(current, -5); /* Block and flush all signals */ sigfillset(&blocked); sigprocmask(SIG_BLOCK, &blocked, NULL); flush_signals(current); /* * We inherited MPOL_INTERLEAVE from the booting kernel. * Set MPOL_DEFAULT to insure node local allocations. */ numa_default_policy(); /* SIG_IGN makes children autoreap: see do_notify_parent(). */ sa.sa.sa_handler = SIG_IGN; sa.sa.sa_flags = 0; siginitset(&sa.sa.sa_mask, sigmask(SIGCHLD)); do_sigaction(SIGCHLD, &sa, (struct k_sigaction *)0); set_current_state(TASK_INTERRUPTIBLE); while (!kthread_should_stop()) { add_wait_queue(&cwq->more_work, &wait); if (list_empty(&cwq->worklist)) schedule(); else __set_current_state(TASK_RUNNING); remove_wait_queue(&cwq->more_work, &wait); if (!list_empty(&cwq->worklist)) run_workqueue(cwq); set_current_state(TASK_INTERRUPTIBLE); } __set_current_state(TASK_RUNNING); return 0;} static void flush_cpu_workqueue(struct cpu_workqueue_struct *cwq){ if (cwq->thread == current) { /* * Probably keventd trying to flush its own queue. So simply run * it by hand rather than deadlocking. */ run_workqueue(cwq); } else { DEFINE_WAIT(wait); long sequence_needed; spin_lock_irq(&cwq->lock); sequence_needed = cwq->insert_sequence; while (sequence_needed - cwq->remove_sequence > 0) { prepare_to_wait(&cwq->work_done, &wait, TASK_UNINTERRUPTIBLE); spin_unlock_irq(&cwq->lock); schedule(); spin_lock_irq(&cwq->lock); } finish_wait(&cwq->work_done, &wait); spin_unlock_irq(&cwq->lock); }} /** * flush_workqueue - ensure that any scheduled work has run to completion. * @wq: workqueue to flush * * Forces execution of the workqueue and blocks until its completion. * This is typically used in driver shutdown handlers. * * This function will sample each workqueue's current insert_sequence number and * will sleep until the head sequence is greater than or equal to that. This * means that we sleep until all works which were queued on entry have been * handled, but we are not livelocked by new incoming ones. * * This function used to run the workqueues itself. Now we just wait for the * helper threads to do it. */void fastcall flush_workqueue(struct workqueue_struct *wq){ might_sleep(); if (is_single_threaded(wq)) { /* Always use first cpu's area. */ flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, singlethread_cpu)); } else { int cpu; mutex_lock(&workqueue_mutex); for_each_online_cpu(cpu) flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu)); mutex_unlock(&workqueue_mutex); }}EXPORT_SYMBOL_GPL(flush_workqueue); static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq, int cpu){ struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); struct task_struct *p; spin_lock_init(&cwq->lock); cwq->wq = wq; cwq->thread = NULL; cwq->insert_sequence = 0; cwq->remove_sequence = 0; INIT_LIST_HEAD(&cwq->worklist); init_waitqueue_head(&cwq->more_work); init_waitqueue_head(&cwq->work_done); if (is_single_threaded(wq)) p = kthread_create(worker_thread, cwq, "%s", wq->name); else p = kthread_create(worker_thread, cwq, "%s/%d", wq->name, cpu); if (IS_ERR(p)) return NULL; cwq->thread = p; return p;} struct workqueue_struct *__create_workqueue(const char *name, int singlethread){ int cpu, destroy = 0; struct workqueue_struct *wq; struct task_struct *p; wq = kzalloc(sizeof(*wq), GFP_KERNEL); if (!wq) return NULL; wq->cpu_wq = alloc_percpu(struct cpu_workqueue_struct); if (!wq->cpu_wq) { kfree(wq); return NULL; } wq->name = name; mutex_lock(&workqueue_mutex); if (singlethread) { INIT_LIST_HEAD(&wq->list); p = create_workqueue_thread(wq, singlethread_cpu); if (!p) destroy = 1; else wake_up_process(p); } else { list_add(&wq->list, &workqueues); for_each_online_cpu(cpu) { p = create_workqueue_thread(wq, cpu); if (p) { kthread_bind(p, cpu); wake_up_process(p); } else destroy = 1; } } mutex_unlock(&workqueue_mutex); /* * Was there any error during startup? If yes then clean up: */ if (destroy) { destroy_workqueue(wq); wq = NULL; } return wq;}EXPORT_SYMBOL_GPL(__create_workqueue); static void cleanup_workqueue_thread(struct workqueue_struct *wq, int cpu){ struct cpu_workqueue_struct *cwq; unsigned long flags; struct task_struct *p; cwq = per_cpu_ptr(wq->cpu_wq, cpu); spin_lock_irqsave(&cwq->lock, flags); p = cwq->thread; cwq->thread = NULL; spin_unlock_irqrestore(&cwq->lock, flags); if (p) kthread_stop(p);} /** * destroy_workqueue - safely terminate a workqueue * @wq: target workqueue * * Safely destroy a workqueue. All work currently pending will be done first. */void destroy_workqueue(struct workqueue_struct *wq){ int cpu; flush_workqueue(wq); /* We don't need the distraction of CPUs appearing and vanishing. */ mutex_lock(&workqueue_mutex); if (is_single_threaded(wq)) cleanup_workqueue_thread(wq, singlethread_cpu); else { for_each_online_cpu(cpu) cleanup_workqueue_thread(wq, cpu); list_del(&wq->list); } mutex_unlock(&workqueue_mutex); free_percpu(wq->cpu_wq); kfree(wq);}EXPORT_SYMBOL_GPL(destroy_workqueue); static struct workqueue_struct *keventd_wq; /** * schedule_work - put work task in global workqueue * @work: job to be done * * This puts a job in the kernel-global workqueue. */int fastcall schedule_work(struct work_struct *work){ return queue_work(keventd_wq, work);}EXPORT_SYMBOL(schedule_work); /** * schedule_delayed_work - put work task in global workqueue after delay * @dwork: job to be done * @delay: number of jiffies to wait or 0 for immediate execution * * After waiting for a given time this puts a job in the kernel-global * workqueue. */int fastcall schedule_delayed_work(struct delayed_work *dwork, unsigned long delay){ return queue_delayed_work(keventd_wq, dwork, delay);}EXPORT_SYMBOL(schedule_delayed_work); /** * schedule_delayed_work_on - queue work in global workqueue on CPU after delay * @cpu: cpu to use * @dwork: job to be done * @delay: number of jiffies to wait * * After waiting for a given time this puts a job in the kernel-global * workqueue on the specified CPU. */int schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay){ return queue_delayed_work_on(cpu, keventd_wq, dwork, delay);Lines 1–500 of 709. 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/* * linux/kernel/workqueue.c * * Generic mechanism for defining kernel helper threads for running * arbitrary tasks in process context. * * Started by Ingo Molnar, Copyright (C) 2002 * * Derived from the taskqueue/keventd code by: * * David Woodhouse <dwmw2@infradead.org> * Andrew Morton <andrewm@uow.edu.au> * Kai Petzke <wpp@marie.physik.tu-berlin.de> * Theodore Ts'o <tytso@mit.edu> * * Made to use alloc_percpu by Christoph Lameter <clameter@sgi.com>. */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/sched.h> #include <linux/init.h> #include <linux/signal.h> #include <linux/completion.h> #include <linux/workqueue.h> #include <linux/slab.h> #include <linux/cpu.h> #include <linux/notifier.h> #include <linux/kthread.h> #include <linux/hardirq.h> #include <linux/mempolicy.h> /* * The per-CPU workqueue (if single thread, we always use the first * possible cpu). * * The sequence counters are for flush_scheduled_work(). It wants to wait * until all currently-scheduled works are completed, but it doesn't * want to be livelocked by new, incoming ones. So it waits until * remove_sequence is >= the insert_sequence which pertained when * flush_scheduled_work() was called. */ struct cpu_workqueue_struct { spinlock_t lock; long remove_sequence; /* Least-recently added (next to run) */ long insert_sequence; /* Next to add */ struct list_head worklist; wait_queue_head_t more_work; wait_queue_head_t work_done; struct workqueue_struct *wq; struct task_struct *thread; int run_depth; /* Detect run_workqueue() recursion depth */ } ____cacheline_aligned; /* * The externally visible workqueue abstraction is an array of * per-CPU workqueues: */ struct workqueue_struct { struct cpu_workqueue_struct *cpu_wq; const char *name; struct list_head list; /* Empty if single thread */ }; /* All the per-cpu workqueues on the system, for hotplug cpu to add/remove threads to each one as cpus come/go. */ static DEFINE_MUTEX(workqueue_mutex); static LIST_HEAD(workqueues); static int singlethread_cpu; /* If it's single threaded, it isn't in the list of workqueues. */ static inline int is_single_threaded(struct workqueue_struct *wq) { return list_empty(&wq->list); } /* Preempt must be disabled. */ static void __queue_work(struct cpu_workqueue_struct *cwq, struct work_struct *work) { unsigned long flags; spin_lock_irqsave(&cwq->lock, flags); work->wq_data = cwq; list_add_tail(&work->entry, &cwq->worklist); cwq->insert_sequence++; wake_up(&cwq->more_work); spin_unlock_irqrestore(&cwq->lock, flags); } /** * queue_work - queue work on a workqueue * @wq: workqueue to use * @work: work to queue * * Returns 0 if @work was already on a queue, non-zero otherwise. * * We queue the work to the CPU it was submitted, but there is no * guarantee that it will be processed by that CPU. */ int fastcall queue_work(struct workqueue_struct *wq, struct work_struct *work) { int ret = 0, cpu = get_cpu(); if (!test_and_set_bit(0, &work->pending)) { if (unlikely(is_single_threaded(wq))) cpu = singlethread_cpu; BUG_ON(!list_empty(&work->entry)); __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work); ret = 1; } put_cpu(); return ret; } EXPORT_SYMBOL_GPL(queue_work); static void delayed_work_timer_fn(unsigned long __data) { struct delayed_work *dwork = (struct delayed_work *)__data; struct workqueue_struct *wq = dwork->work.wq_data; int cpu = smp_processor_id(); if (unlikely(is_single_threaded(wq))) cpu = singlethread_cpu; __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), &dwork->work); } /** * queue_delayed_work - queue work on a workqueue after delay * @wq: workqueue to use * @work: delayable work to queue * @delay: number of jiffies to wait before queueing * * Returns 0 if @work was already on a queue, non-zero otherwise. */ int fastcall queue_delayed_work(struct workqueue_struct *wq, struct delayed_work *dwork, unsigned long delay) { int ret = 0; struct timer_list *timer = &dwork->timer; struct work_struct *work = &dwork->work; if (delay == 0) return queue_work(wq, work); if (!test_and_set_bit(0, &work->pending)) { BUG_ON(timer_pending(timer)); BUG_ON(!list_empty(&work->entry)); /* This stores wq for the moment, for the timer_fn */ work->wq_data = wq; timer->expires = jiffies + delay; timer->data = (unsigned long)dwork; timer->function = delayed_work_timer_fn; add_timer(timer); ret = 1; } return ret; } EXPORT_SYMBOL_GPL(queue_delayed_work); /** * queue_delayed_work_on - queue work on specific CPU after delay * @cpu: CPU number to execute work on * @wq: workqueue to use * @work: work to queue * @delay: number of jiffies to wait before queueing * * Returns 0 if @work was already on a queue, non-zero otherwise. */ int queue_delayed_work_on(int cpu, struct workqueue_struct *wq, struct delayed_work *dwork, unsigned long delay) { int ret = 0; struct timer_list *timer = &dwork->timer; struct work_struct *work = &dwork->work; if (!test_and_set_bit(0, &work->pending)) { BUG_ON(timer_pending(timer)); BUG_ON(!list_empty(&work->entry)); /* This stores wq for the moment, for the timer_fn */ work->wq_data = wq; timer->expires = jiffies + delay; timer->data = (unsigned long)dwork; timer->function = delayed_work_timer_fn; add_timer_on(timer, cpu); ret = 1; } return ret; } EXPORT_SYMBOL_GPL(queue_delayed_work_on); static void run_workqueue(struct cpu_workqueue_struct *cwq) { unsigned long flags; /* * Keep taking off work from the queue until * done. */ spin_lock_irqsave(&cwq->lock, flags); cwq->run_depth++; if (cwq->run_depth > 3) { /* morton gets to eat his hat */ printk("%s: recursion depth exceeded: %d\n", __FUNCTION__, cwq->run_depth); dump_stack(); } while (!list_empty(&cwq->worklist)) { struct work_struct *work = list_entry(cwq->worklist.next, struct work_struct, entry); work_func_t f = work->func; void *data = work->data; list_del_init(cwq->worklist.next); spin_unlock_irqrestore(&cwq->lock, flags); BUG_ON(work->wq_data != cwq); clear_bit(0, &work->pending); f(data); spin_lock_irqsave(&cwq->lock, flags); cwq->remove_sequence++; wake_up(&cwq->work_done); } cwq->run_depth--; spin_unlock_irqrestore(&cwq->lock, flags); } static int worker_thread(void *__cwq) { struct cpu_workqueue_struct *cwq = __cwq; DECLARE_WAITQUEUE(wait, current); struct k_sigaction sa; sigset_t blocked; current->flags |= PF_NOFREEZE; set_user_nice(current, -5); /* Block and flush all signals */ sigfillset(&blocked); sigprocmask(SIG_BLOCK, &blocked, NULL); flush_signals(current); /* * We inherited MPOL_INTERLEAVE from the booting kernel. * Set MPOL_DEFAULT to insure node local allocations. */ numa_default_policy(); /* SIG_IGN makes children autoreap: see do_notify_parent(). */ sa.sa.sa_handler = SIG_IGN; sa.sa.sa_flags = 0; siginitset(&sa.sa.sa_mask, sigmask(SIGCHLD)); do_sigaction(SIGCHLD, &sa, (struct k_sigaction *)0); set_current_state(TASK_INTERRUPTIBLE); while (!kthread_should_stop()) { add_wait_queue(&cwq->more_work, &wait); if (list_empty(&cwq->worklist)) schedule(); else __set_current_state(TASK_RUNNING); remove_wait_queue(&cwq->more_work, &wait); if (!list_empty(&cwq->worklist)) run_workqueue(cwq); set_current_state(TASK_INTERRUPTIBLE); } __set_current_state(TASK_RUNNING); return 0; } static void flush_cpu_workqueue(struct cpu_workqueue_struct *cwq) { if (cwq->thread == current) { /* * Probably keventd trying to flush its own queue. So simply run * it by hand rather than deadlocking. */ run_workqueue(cwq); } else { DEFINE_WAIT(wait); long sequence_needed; spin_lock_irq(&cwq->lock); sequence_needed = cwq->insert_sequence; while (sequence_needed - cwq->remove_sequence > 0) { prepare_to_wait(&cwq->work_done, &wait, TASK_UNINTERRUPTIBLE); spin_unlock_irq(&cwq->lock); schedule(); spin_lock_irq(&cwq->lock); } finish_wait(&cwq->work_done, &wait); spin_unlock_irq(&cwq->lock); } } /** * flush_workqueue - ensure that any scheduled work has run to completion. * @wq: workqueue to flush * * Forces execution of the workqueue and blocks until its completion. * This is typically used in driver shutdown handlers. * * This function will sample each workqueue's current insert_sequence number and * will sleep until the head sequence is greater than or equal to that. This * means that we sleep until all works which were queued on entry have been * handled, but we are not livelocked by new incoming ones. * * This function used to run the workqueues itself. Now we just wait for the * helper threads to do it. */ void fastcall flush_workqueue(struct workqueue_struct *wq) { might_sleep(); if (is_single_threaded(wq)) { /* Always use first cpu's area. */ flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, singlethread_cpu)); } else { int cpu; mutex_lock(&workqueue_mutex); for_each_online_cpu(cpu) flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu)); mutex_unlock(&workqueue_mutex); } } EXPORT_SYMBOL_GPL(flush_workqueue); static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq, int cpu) { struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); struct task_struct *p; spin_lock_init(&cwq->lock); cwq->wq = wq; cwq->thread = NULL; cwq->insert_sequence = 0; cwq->remove_sequence = 0; INIT_LIST_HEAD(&cwq->worklist); init_waitqueue_head(&cwq->more_work); init_waitqueue_head(&cwq->work_done); if (is_single_threaded(wq)) p = kthread_create(worker_thread, cwq, "%s", wq->name); else p = kthread_create(worker_thread, cwq, "%s/%d", wq->name, cpu); if (IS_ERR(p)) return NULL; cwq->thread = p; return p; } struct workqueue_struct *__create_workqueue(const char *name, int singlethread) { int cpu, destroy = 0; struct workqueue_struct *wq; struct task_struct *p; wq = kzalloc(sizeof(*wq), GFP_KERNEL); if (!wq) return NULL; wq->cpu_wq = alloc_percpu(struct cpu_workqueue_struct); if (!wq->cpu_wq) { kfree(wq); return NULL; } wq->name = name; mutex_lock(&workqueue_mutex); if (singlethread) { INIT_LIST_HEAD(&wq->list); p = create_workqueue_thread(wq, singlethread_cpu); if (!p) destroy = 1; else wake_up_process(p); } else { list_add(&wq->list, &workqueues); for_each_online_cpu(cpu) { p = create_workqueue_thread(wq, cpu); if (p) { kthread_bind(p, cpu); wake_up_process(p); } else destroy = 1; } } mutex_unlock(&workqueue_mutex); /* * Was there any error during startup? If yes then clean up: */ if (destroy) { destroy_workqueue(wq); wq = NULL; } return wq; } EXPORT_SYMBOL_GPL(__create_workqueue); static void cleanup_workqueue_thread(struct workqueue_struct *wq, int cpu) { struct cpu_workqueue_struct *cwq; unsigned long flags; struct task_struct *p; cwq = per_cpu_ptr(wq->cpu_wq, cpu); spin_lock_irqsave(&cwq->lock, flags); p = cwq->thread; cwq->thread = NULL; spin_unlock_irqrestore(&cwq->lock, flags); if (p) kthread_stop(p); } /** * destroy_workqueue - safely terminate a workqueue * @wq: target workqueue * * Safely destroy a workqueue. All work currently pending will be done first. */ void destroy_workqueue(struct workqueue_struct *wq) { int cpu; flush_workqueue(wq); /* We don't need the distraction of CPUs appearing and vanishing. */ mutex_lock(&workqueue_mutex); if (is_single_threaded(wq)) cleanup_workqueue_thread(wq, singlethread_cpu); else { for_each_online_cpu(cpu) cleanup_workqueue_thread(wq, cpu); list_del(&wq->list); } mutex_unlock(&workqueue_mutex); free_percpu(wq->cpu_wq); kfree(wq); } EXPORT_SYMBOL_GPL(destroy_workqueue); static struct workqueue_struct *keventd_wq; /** * schedule_work - put work task in global workqueue * @work: job to be done * * This puts a job in the kernel-global workqueue. */ int fastcall schedule_work(struct work_struct *work) { return queue_work(keventd_wq, work); } EXPORT_SYMBOL(schedule_work); /** * schedule_delayed_work - put work task in global workqueue after delay * @dwork: job to be done * @delay: number of jiffies to wait or 0 for immediate execution * * After waiting for a given time this puts a job in the kernel-global * workqueue. */ int fastcall schedule_delayed_work(struct delayed_work *dwork, unsigned long delay) { return queue_delayed_work(keventd_wq, dwork, delay); } EXPORT_SYMBOL(schedule_delayed_work); /** * schedule_delayed_work_on - queue work in global workqueue on CPU after delay * @cpu: cpu to use * @dwork: job to be done * @delay: number of jiffies to wait * * After waiting for a given time this puts a job in the kernel-global * workqueue on the specified CPU. */ int schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay) { return queue_delayed_work_on(cpu, keventd_wq, dwork, delay);