Re: [PATCHv5 12/15] writeback: optimize periodic bdi thread wakeups

Artem Bityutskiy
2010-07-25T10:48:35Z

On Sun, 2010-07-25 at 11:29 +0300, Artem Bityutskiy wrote:
> +static void wakeup_timer_fn(unsigned long data)
> +{
> + struct backing_dev_info *bdi = (struct backing_dev_info *)data;
> +
> + spin_lock(&bdi->wb_lock);
> + if (bdi->wb.task) {
> + wake_up_process(bdi->wb.task);
> + } else {
> + /*
> + * When bdi tasks are inactive for long time, they are killed.
> + * In this case we have to wake-up the forker thread which
> + * should create and run the bdi thread.
> + */
> + wake_up_process(default_backing_dev_info.wb.task);
> + }
> + spin_unlock(&bdi->wb_lock);
> +}

OK, since now we use this lock in a timer, this should become a
spin_lock_bh().

--
Best Regards,
Artem Bityutskiy (Артём Битюцкий)