Merge git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog

[pandora-kernel.git] / kernel / workqueue.c

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 3bebf73..58e5c15 100644 (file)
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -282,8 +282,8 @@ static int worker_thread(void *__cwq)
        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);
 
@@ -382,16 +382,16 @@ void fastcall flush_workqueue(struct workqueue_struct *wq)
 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
@@ -457,10 +457,28 @@ static void wait_on_work(struct work_struct *work)
                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.
@@ -476,31 +494,26 @@ static void wait_on_work(struct work_struct *work)
  * 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;
 
@@ -739,18 +752,17 @@ static void cleanup_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu)
        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;
 }