diff options
Diffstat (limited to 'kernel/workqueue.c')
| -rw-r--r-- | kernel/workqueue.c | 220 |
1 files changed, 167 insertions, 53 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 3df9bfc7ff7..db49886bfae 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -29,6 +29,9 @@ #include <linux/kthread.h> #include <linux/hardirq.h> #include <linux/mempolicy.h> +#include <linux/freezer.h> +#include <linux/kallsyms.h> +#include <linux/debug_locks.h> /* * The per-CPU workqueue (if single thread, we always use the first @@ -55,6 +58,8 @@ struct cpu_workqueue_struct { struct task_struct *thread; int run_depth; /* Detect run_workqueue() recursion depth */ + + int freezeable; /* Freeze the thread during suspend */ } ____cacheline_aligned; /* @@ -80,6 +85,99 @@ static inline int is_single_threaded(struct workqueue_struct *wq) return list_empty(&wq->list); } +/* + * Set the workqueue on which a work item is to be run + * - Must *only* be called if the pending flag is set + */ +static inline void set_wq_data(struct work_struct *work, void *wq) +{ + unsigned long new; + + BUG_ON(!work_pending(work)); + + new = (unsigned long) wq | (1UL << WORK_STRUCT_PENDING); + new |= work->management & WORK_STRUCT_FLAG_MASK; + work->management = new; +} + +static inline void *get_wq_data(struct work_struct *work) +{ + return (void *) (work->management & WORK_STRUCT_WQ_DATA_MASK); +} + +static int __run_work(struct cpu_workqueue_struct *cwq, struct work_struct *work) +{ + int ret = 0; + unsigned long flags; + + spin_lock_irqsave(&cwq->lock, flags); + /* + * We need to re-validate the work info after we've gotten + * the cpu_workqueue lock. We can run the work now iff: + * + * - the wq_data still matches the cpu_workqueue_struct + * - AND the work is still marked pending + * - AND the work is still on a list (which will be this + * workqueue_struct list) + * + * All these conditions are important, because we + * need to protect against the work being run right + * now on another CPU (all but the last one might be + * true if it's currently running and has not been + * released yet, for example). + */ + if (get_wq_data(work) == cwq + && work_pending(work) + && !list_empty(&work->entry)) { + work_func_t f = work->func; + list_del_init(&work->entry); + spin_unlock_irqrestore(&cwq->lock, flags); + + if (!test_bit(WORK_STRUCT_NOAUTOREL, &work->management)) + work_release(work); + f(work); + + spin_lock_irqsave(&cwq->lock, flags); + cwq->remove_sequence++; + wake_up(&cwq->work_done); + ret = 1; + } + spin_unlock_irqrestore(&cwq->lock, flags); + return ret; +} + +/** + * run_scheduled_work - run scheduled work synchronously + * @work: work to run + * + * This checks if the work was pending, and runs it + * synchronously if so. It returns a boolean to indicate + * whether it had any scheduled work to run or not. + * + * NOTE! This _only_ works for normal work_structs. You + * CANNOT use this for delayed work, because the wq data + * for delayed work will not point properly to the per- + * CPU workqueue struct, but will change! + */ +int fastcall run_scheduled_work(struct work_struct *work) +{ + for (;;) { + struct cpu_workqueue_struct *cwq; + + if (!work_pending(work)) + return 0; + if (list_empty(&work->entry)) + return 0; + /* NOTE! This depends intimately on __queue_work! */ + cwq = get_wq_data(work); + if (!cwq) + return 0; + if (__run_work(cwq, work)) + return 1; + } +} +EXPORT_SYMBOL(run_scheduled_work); + /* Preempt must be disabled. */ static void __queue_work(struct cpu_workqueue_struct *cwq, struct work_struct *work) @@ -87,7 +185,7 @@ static void __queue_work(struct cpu_workqueue_struct *cwq, unsigned long flags; spin_lock_irqsave(&cwq->lock, flags); - work->wq_data = cwq; + set_wq_data(work, cwq); list_add_tail(&work->entry, &cwq->worklist); cwq->insert_sequence++; wake_up(&cwq->more_work); @@ -99,7 +197,7 @@ static void __queue_work(struct cpu_workqueue_struct *cwq, * @wq: workqueue to use * @work: work to queue * - * Returns non-zero if it was successfully added. + * 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. @@ -108,7 +206,7 @@ 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 (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) { if (unlikely(is_single_threaded(wq))) cpu = singlethread_cpu; BUG_ON(!list_empty(&work->entry)); @@ -122,38 +220,42 @@ EXPORT_SYMBOL_GPL(queue_work); static void delayed_work_timer_fn(unsigned long __data) { - struct work_struct *work = (struct work_struct *)__data; - struct workqueue_struct *wq = work->wq_data; + struct delayed_work *dwork = (struct delayed_work *)__data; + struct workqueue_struct *wq = get_wq_data(&dwork->work); int cpu = smp_processor_id(); if (unlikely(is_single_threaded(wq))) cpu = singlethread_cpu; - __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work); + __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: work to queue + * @work: delayable work to queue * @delay: number of jiffies to wait before queueing * - * Returns non-zero if it was successfully added. + * Returns 0 if @work was already on a queue, non-zero otherwise. */ int fastcall queue_delayed_work(struct workqueue_struct *wq, - struct work_struct *work, unsigned long delay) + struct delayed_work *dwork, unsigned long delay) { int ret = 0; - struct timer_list *timer = &work->timer; + 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)) { + if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) { 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; + set_wq_data(work, wq); timer->expires = jiffies + delay; - timer->data = (unsigned long)work; + timer->data = (unsigned long)dwork; timer->function = delayed_work_timer_fn; add_timer(timer); ret = 1; @@ -169,22 +271,23 @@ EXPORT_SYMBOL_GPL(queue_delayed_work); * @work: work to queue * @delay: number of jiffies to wait before queueing * - * Returns non-zero if it was successfully added. + * Returns 0 if @work was already on a queue, non-zero otherwise. */ int queue_delayed_work_on(int cpu, struct workqueue_struct *wq, - struct work_struct *work, unsigned long delay) + struct delayed_work *dwork, unsigned long delay) { int ret = 0; - struct timer_list *timer = &work->timer; + struct timer_list *timer = &dwork->timer; + struct work_struct *work = &dwork->work; - if (!test_and_set_bit(0, &work->pending)) { + if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) { 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; + set_wq_data(work, wq); timer->expires = jiffies + delay; - timer->data = (unsigned long)work; + timer->data = (unsigned long)dwork; timer->function = delayed_work_timer_fn; add_timer_on(timer, cpu); ret = 1; @@ -212,15 +315,26 @@ static void run_workqueue(struct cpu_workqueue_struct *cwq) while (!list_empty(&cwq->worklist)) { struct work_struct *work = list_entry(cwq->worklist.next, struct work_struct, entry); - void (*f) (void *) = work->func; - void *data = work->data; + work_func_t f = work->func; 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); + BUG_ON(get_wq_data(work) != cwq); + if (!test_bit(WORK_STRUCT_NOAUTOREL, &work->management)) + work_release(work); + f(work); + + if (unlikely(in_atomic() || lockdep_depth(current) > 0)) { + printk(KERN_ERR "BUG: workqueue leaked lock or atomic: " + "%s/0x%08x/%d\n", + current->comm, preempt_count(), + current->pid); + printk(KERN_ERR " last function: "); + print_symbol("%s\n", (unsigned long)f); + debug_show_held_locks(current); + dump_stack(); + } spin_lock_irqsave(&cwq->lock, flags); cwq->remove_sequence++; @@ -237,7 +351,8 @@ static int worker_thread(void *__cwq) struct k_sigaction sa; sigset_t blocked; - current->flags |= PF_NOFREEZE; + if (!cwq->freezeable) + current->flags |= PF_NOFREEZE; set_user_nice(current, -5); @@ -260,6 +375,9 @@ static int worker_thread(void *__cwq) set_current_state(TASK_INTERRUPTIBLE); while (!kthread_should_stop()) { + if (cwq->freezeable) + try_to_freeze(); + add_wait_queue(&cwq->more_work, &wait); if (list_empty(&cwq->worklist)) schedule(); @@ -336,7 +454,7 @@ void fastcall flush_workqueue(struct workqueue_struct *wq) EXPORT_SYMBOL_GPL(flush_workqueue); static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq, - int cpu) + int cpu, int freezeable) { struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); struct task_struct *p; @@ -346,6 +464,7 @@ static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq, cwq->thread = NULL; cwq->insert_sequence = 0; cwq->remove_sequence = 0; + cwq->freezeable = freezeable; INIT_LIST_HEAD(&cwq->worklist); init_waitqueue_head(&cwq->more_work); init_waitqueue_head(&cwq->work_done); @@ -361,7 +480,7 @@ static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq, } struct workqueue_struct *__create_workqueue(const char *name, - int singlethread) + int singlethread, int freezeable) { int cpu, destroy = 0; struct workqueue_struct *wq; @@ -381,7 +500,7 @@ struct workqueue_struct *__create_workqueue(const char *name, mutex_lock(&workqueue_mutex); if (singlethread) { INIT_LIST_HEAD(&wq->list); - p = create_workqueue_thread(wq, singlethread_cpu); + p = create_workqueue_thread(wq, singlethread_cpu, freezeable); if (!p) destroy = 1; else @@ -389,7 +508,7 @@ struct workqueue_struct *__create_workqueue(const char *name, } else { list_add(&wq->list, &workqueues); for_each_online_cpu(cpu) { - p = create_workqueue_thread(wq, cpu); + p = create_workqueue_thread(wq, cpu, freezeable); if (p) { kthread_bind(p, cpu); wake_up_process(p); @@ -468,38 +587,37 @@ EXPORT_SYMBOL(schedule_work); /** * schedule_delayed_work - put work task in global workqueue after delay - * @work: job to be done - * @delay: number of jiffies to wait + * @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 work_struct *work, unsigned long delay) +int fastcall schedule_delayed_work(struct delayed_work *dwork, unsigned long delay) { - return queue_delayed_work(keventd_wq, work, 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 - * @work: job to be done + * @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 work_struct *work, unsigned long delay) + struct delayed_work *dwork, unsigned long delay) { - return queue_delayed_work_on(cpu, keventd_wq, work, delay); + return queue_delayed_work_on(cpu, keventd_wq, dwork, delay); } EXPORT_SYMBOL(schedule_delayed_work_on); /** * schedule_on_each_cpu - call a function on each online CPU from keventd * @func: the function to call - * @info: a pointer to pass to func() * * Returns zero on success. * Returns -ve errno on failure. @@ -508,7 +626,7 @@ EXPORT_SYMBOL(schedule_delayed_work_on); * * schedule_on_each_cpu() is very slow. */ -int schedule_on_each_cpu(void (*func)(void *info), void *info) +int schedule_on_each_cpu(work_func_t func) { int cpu; struct work_struct *works; @@ -519,7 +637,7 @@ int schedule_on_each_cpu(void (*func)(void *info), void *info) mutex_lock(&workqueue_mutex); for_each_online_cpu(cpu) { - INIT_WORK(per_cpu_ptr(works, cpu), func, info); + INIT_WORK(per_cpu_ptr(works, cpu), func); __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu), per_cpu_ptr(works, cpu)); } @@ -539,12 +657,12 @@ EXPORT_SYMBOL(flush_scheduled_work); * cancel_rearming_delayed_workqueue - reliably kill off a delayed * work whose handler rearms the delayed work. * @wq: the controlling workqueue structure - * @work: the delayed work struct + * @dwork: the delayed work struct */ void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq, - struct work_struct *work) + struct delayed_work *dwork) { - while (!cancel_delayed_work(work)) + while (!cancel_delayed_work(dwork)) flush_workqueue(wq); } EXPORT_SYMBOL(cancel_rearming_delayed_workqueue); @@ -552,18 +670,17 @@ EXPORT_SYMBOL(cancel_rearming_delayed_workqueue); /** * cancel_rearming_delayed_work - reliably kill off a delayed keventd * work whose handler rearms the delayed work. - * @work: the delayed work struct + * @dwork: the delayed work struct */ -void cancel_rearming_delayed_work(struct work_struct *work) +void cancel_rearming_delayed_work(struct delayed_work *dwork) { - cancel_rearming_delayed_workqueue(keventd_wq, work); + cancel_rearming_delayed_workqueue(keventd_wq, dwork); } EXPORT_SYMBOL(cancel_rearming_delayed_work); /** * execute_in_process_context - reliably execute the routine with user context * @fn: the function to execute - * @data: data to pass to the function * @ew: guaranteed storage for the execute work structure (must * be available when the work executes) * @@ -573,15 +690,14 @@ EXPORT_SYMBOL(cancel_rearming_delayed_work); * Returns: 0 - function was executed * 1 - function was scheduled for execution */ -int execute_in_process_context(void (*fn)(void *data), void *data, - struct execute_work *ew) +int execute_in_process_context(work_func_t fn, struct execute_work *ew) { if (!in_interrupt()) { - fn(data); + fn(&ew->work); return 0; } - INIT_WORK(&ew->work, fn, data); + INIT_WORK(&ew->work, fn); schedule_work(&ew->work); return 1; @@ -609,7 +725,6 @@ int current_is_keventd(void) } -#ifdef CONFIG_HOTPLUG_CPU /* Take the work from this (downed) CPU. */ static void take_over_work(struct workqueue_struct *wq, unsigned int cpu) { @@ -642,7 +757,7 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, mutex_lock(&workqueue_mutex); /* Create a new workqueue thread for it. */ list_for_each_entry(wq, &workqueues, list) { - if (!create_workqueue_thread(wq, hotcpu)) { + if (!create_workqueue_thread(wq, hotcpu, 0)) { printk("workqueue for %i failed\n", hotcpu); return NOTIFY_BAD; } @@ -692,7 +807,6 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, return NOTIFY_OK; } -#endif void init_workqueues(void) { |