X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Fworkqueue.c;h=db49886bfae17271ee19709a984c57c208c5065b;hb=7c3ab7381e79dfc7db14a67c6f4f3285664e1ec2;hp=967479756511a9c15e10e8fa3fb27c346982da7f;hpb=365970a1ea76d81cb1ad2f652acb605f06dae256;p=linux-2.6 diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 9674797565..db49886bfa 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -29,6 +29,9 @@ #include #include #include +#include +#include +#include /* * 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; /* @@ -80,22 +85,19 @@ 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->management & WORK_STRUCT_FLAG_MASK; + work->management = new; } static inline void *get_wq_data(struct work_struct *work) @@ -103,6 +105,79 @@ 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) @@ -241,14 +316,25 @@ static void run_workqueue(struct cpu_workqueue_struct *cwq) 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(get_wq_data(work) != cwq); - clear_bit(WORK_STRUCT_PENDING, &work->management); - f(data); + 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++; @@ -265,7 +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); @@ -288,6 +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(); @@ -364,7 +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; @@ -374,6 +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); @@ -389,7 +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; @@ -409,7 +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 @@ -417,7 +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); @@ -527,7 +618,6 @@ 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. @@ -536,7 +626,7 @@ EXPORT_SYMBOL(schedule_delayed_work_on); * * schedule_on_each_cpu() is very slow. */ -int schedule_on_each_cpu(work_func_t func, void *info) +int schedule_on_each_cpu(work_func_t func) { int cpu; struct work_struct *works; @@ -547,7 +637,7 @@ int schedule_on_each_cpu(work_func_t func, 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)); } @@ -591,7 +681,6 @@ 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) * @@ -601,15 +690,14 @@ EXPORT_SYMBOL(cancel_rearming_delayed_work); * Returns: 0 - function was executed * 1 - function was scheduled for execution */ -int execute_in_process_context(work_func_t fn, 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; @@ -637,7 +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) { @@ -670,7 +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; } @@ -720,7 +807,6 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, return NOTIFY_OK; } -#endif void init_workqueues(void) {