X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=kernel%2Fworkqueue.c;h=b6fa5e63085d65b42f46fe97735751b6f402cab4;hb=2aa6eb313e57a8254b17e60b8bb5e0a2570d7776;hp=c5257316f4b946e343498f96d32ff6e7b3e87dff;hpb=0a01707b289853f56d1c000057b27e243c039722;p=powerpc.git diff --git a/kernel/workqueue.c b/kernel/workqueue.c index c5257316f4..b6fa5e6308 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -85,28 +85,98 @@ 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, old, res; + unsigned long new; + + BUG_ON(!work_pending(work)); - /* assume the pending flag is already set and that the task has already - * been queued on this workqueue */ new = (unsigned long) wq | (1UL << WORK_STRUCT_PENDING); - res = work->management; - if (res != new) { - do { - old = res; - new = (unsigned long) wq; - new |= (old & WORK_STRUCT_FLAG_MASK); - res = cmpxchg(&work->management, old, new); - } while (res != old); - } + new |= WORK_STRUCT_FLAG_MASK & *work_data_bits(work); + atomic_long_set(&work->data, new); } static inline void *get_wq_data(struct work_struct *work) { - return (void *) (work->management & WORK_STRUCT_WQ_DATA_MASK); + return (void *) (atomic_long_read(&work->data) & 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_data_bits(work))) + 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, @@ -136,7 +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(WORK_STRUCT_PENDING, &work->management)) { + if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) { if (unlikely(is_single_threaded(wq))) cpu = singlethread_cpu; BUG_ON(!list_empty(&work->entry)); @@ -148,7 +218,7 @@ int fastcall queue_work(struct workqueue_struct *wq, struct work_struct *work) } EXPORT_SYMBOL_GPL(queue_work); -static void delayed_work_timer_fn(unsigned long __data) +void delayed_work_timer_fn(unsigned long __data) { struct delayed_work *dwork = (struct delayed_work *)__data; struct workqueue_struct *wq = get_wq_data(&dwork->work); @@ -163,7 +233,7 @@ static void delayed_work_timer_fn(unsigned long __data) /** * queue_delayed_work - queue work on a workqueue after delay * @wq: workqueue to use - * @work: delayable work to queue + * @dwork: delayable work to queue * @delay: number of jiffies to wait before queueing * * Returns 0 if @work was already on a queue, non-zero otherwise. @@ -175,10 +245,11 @@ int fastcall queue_delayed_work(struct workqueue_struct *wq, struct timer_list *timer = &dwork->timer; struct work_struct *work = &dwork->work; + timer_stats_timer_set_start_info(timer); if (delay == 0) return queue_work(wq, work); - if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) { + if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) { BUG_ON(timer_pending(timer)); BUG_ON(!list_empty(&work->entry)); @@ -198,7 +269,7 @@ 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 + * @dwork: work to queue * @delay: number of jiffies to wait before queueing * * Returns 0 if @work was already on a queue, non-zero otherwise. @@ -210,7 +281,7 @@ int queue_delayed_work_on(int cpu, struct workqueue_struct *wq, struct timer_list *timer = &dwork->timer; struct work_struct *work = &dwork->work; - if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) { + if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) { BUG_ON(timer_pending(timer)); BUG_ON(!list_empty(&work->entry)); @@ -251,7 +322,7 @@ static void run_workqueue(struct cpu_workqueue_struct *cwq) spin_unlock_irqrestore(&cwq->lock, flags); BUG_ON(get_wq_data(work) != cwq); - if (!test_bit(WORK_STRUCT_NOAUTOREL, &work->management)) + if (!test_bit(WORK_STRUCT_NOAUTOREL, work_data_bits(work))) work_release(work); f(work); @@ -523,8 +594,10 @@ EXPORT_SYMBOL(schedule_work); * 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) +int fastcall schedule_delayed_work(struct delayed_work *dwork, + unsigned long delay) { + timer_stats_timer_set_start_info(&dwork->timer); return queue_delayed_work(keventd_wq, dwork, delay); } EXPORT_SYMBOL(schedule_delayed_work); @@ -567,9 +640,11 @@ int schedule_on_each_cpu(work_func_t func) mutex_lock(&workqueue_mutex); for_each_online_cpu(cpu) { - INIT_WORK(per_cpu_ptr(works, cpu), func); - __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu), - per_cpu_ptr(works, cpu)); + struct work_struct *work = per_cpu_ptr(works, cpu); + + INIT_WORK(work, func); + set_bit(WORK_STRUCT_PENDING, work_data_bits(work)); + __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu), work); } mutex_unlock(&workqueue_mutex); flush_workqueue(keventd_wq); @@ -584,8 +659,7 @@ void flush_scheduled_work(void) EXPORT_SYMBOL(flush_scheduled_work); /** - * cancel_rearming_delayed_workqueue - reliably kill off a delayed - * work whose handler rearms the delayed work. + * cancel_rearming_delayed_workqueue - reliably kill off a delayed work whose handler rearms the delayed work. * @wq: the controlling workqueue structure * @dwork: the delayed work struct */ @@ -598,8 +672,7 @@ void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq, EXPORT_SYMBOL(cancel_rearming_delayed_workqueue); /** - * cancel_rearming_delayed_work - reliably kill off a delayed keventd - * work whose handler rearms the delayed work. + * cancel_rearming_delayed_work - reliably kill off a delayed keventd work whose handler rearms the delayed work. * @dwork: the delayed work struct */ void cancel_rearming_delayed_work(struct delayed_work *dwork)