On Thu 06-04-17 12:23:51, NeilBrown wrote:
[...]
> diff --git a/drivers/block/loop.c b/drivers/block/loop.c
> index 0ecb6461ed81..95679d988725 100644
> --- a/drivers/block/loop.c
> +++ b/drivers/block/loop.c
> @@ -847,10 +847,12 @@ static void loop_unprepare_queue(struct loop_device *lo)
> static int loop_prepare_queue(struct loop_device *lo)
> {
> kthread_init_worker(&lo->worker);
> - lo->worker_task = kthread_run(kthread_worker_fn,
> + lo->worker_task = kthread_create(kthread_worker_fn,
> &lo->worker, "loop%d", lo->lo_number);
> if (IS_ERR(lo->worker_task))
> return -ENOMEM;
> + lo->worker_task->flags |= PF_LESS_THROTTLE;
> + wake_up_process(lo->worker_task);
> set_user_nice(lo->worker_task, MIN_NICE);
> return 0;
This should work for the current implementation because kthread_create
will return only after the full initialization has been done. No idea
whether we can rely on that in future. I also think it would be cleaner
to set the flag on current and keep the current semantic that only
current changes its flags.
So while I do not have a strong opinion on this I think defining loop
specific thread function which set PF_LESS_THROTTLE as the first thing
is more elegant and less error prone longerm. A short comment explaining
why we use the flag there would be also preferred.
I will leave the decision to you.
Thanks.
--
Michal Hocko
SUSE Labs
