struct cpu_workqueue_struct *cwq = __cwq;
DEFINE_WAIT(wait);
- if (!cwq->wq->freezeable)
- current->flags |= PF_NOFREEZE;
+ if (cwq->wq->freezeable)
+ set_freezable();
set_user_nice(current, -5);
EXPORT_SYMBOL_GPL(flush_workqueue);
/*
- * Upon a successful return, the caller "owns" WORK_STRUCT_PENDING bit,
+ * Upon a successful return (>= 0), the caller "owns" WORK_STRUCT_PENDING bit,
* so this work can't be re-armed in any way.
*/
static int try_to_grab_pending(struct work_struct *work)
{
struct cpu_workqueue_struct *cwq;
- int ret = 0;
+ int ret = -1;
if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work)))
- return 1;
+ return 0;
/*
* The queueing is in progress, or it is already queued. Try to
wait_on_cpu_work(per_cpu_ptr(wq->cpu_wq, cpu), work);
}
+static int __cancel_work_timer(struct work_struct *work,
+ struct timer_list* timer)
+{
+ int ret;
+
+ do {
+ ret = (timer && likely(del_timer(timer)));
+ if (!ret)
+ ret = try_to_grab_pending(work);
+ wait_on_work(work);
+ } while (unlikely(ret < 0));
+
+ work_clear_pending(work);
+ return ret;
+}
+
/**
* cancel_work_sync - block until a work_struct's callback has terminated
* @work: the work which is to be flushed
*
+ * Returns true if @work was pending.
+ *
* cancel_work_sync() will cancel the work if it is queued. If the work's
* callback appears to be running, cancel_work_sync() will block until it
* has completed.
* The caller must ensure that workqueue_struct on which this work was last
* queued can't be destroyed before this function returns.
*/
-void cancel_work_sync(struct work_struct *work)
+int cancel_work_sync(struct work_struct *work)
{
- while (!try_to_grab_pending(work))
- cpu_relax();
- wait_on_work(work);
- work_clear_pending(work);
+ return __cancel_work_timer(work, NULL);
}
EXPORT_SYMBOL_GPL(cancel_work_sync);
/**
- * cancel_rearming_delayed_work - reliably kill off a delayed work.
+ * cancel_delayed_work_sync - reliably kill off a delayed work.
* @dwork: the delayed work struct
*
+ * Returns true if @dwork was pending.
+ *
* It is possible to use this function if @dwork rearms itself via queue_work()
* or queue_delayed_work(). See also the comment for cancel_work_sync().
*/
-void cancel_rearming_delayed_work(struct delayed_work *dwork)
+int cancel_delayed_work_sync(struct delayed_work *dwork)
{
- while (!del_timer(&dwork->timer) &&
- !try_to_grab_pending(&dwork->work))
- cpu_relax();
- wait_on_work(&dwork->work);
- work_clear_pending(&dwork->work);
+ return __cancel_work_timer(&dwork->work, &dwork->timer);
}
-EXPORT_SYMBOL(cancel_rearming_delayed_work);
+EXPORT_SYMBOL(cancel_delayed_work_sync);
static struct workqueue_struct *keventd_wq __read_mostly;
int current_is_keventd(void)
{
struct cpu_workqueue_struct *cwq;
- int cpu = smp_processor_id(); /* preempt-safe: keventd is per-cpu */
+ int cpu = raw_smp_processor_id(); /* preempt-safe: keventd is per-cpu */
int ret = 0;
BUG_ON(!keventd_wq);
if (cwq->thread == NULL)
return;
+ flush_cpu_workqueue(cwq);
/*
- * If the caller is CPU_DEAD the single flush_cpu_workqueue()
- * is not enough, a concurrent flush_workqueue() can insert a
- * barrier after us.
+ * If the caller is CPU_DEAD and cwq->worklist was not empty,
+ * a concurrent flush_workqueue() can insert a barrier after us.
+ * However, in that case run_workqueue() won't return and check
+ * kthread_should_stop() until it flushes all work_struct's.
* When ->worklist becomes empty it is safe to exit because no
* more work_structs can be queued on this cwq: flush_workqueue
* checks list_empty(), and a "normal" queue_work() can't use
* a dead CPU.
*/
- while (flush_cpu_workqueue(cwq))
- ;
-
kthread_stop(cwq->thread);
cwq->thread = NULL;
}