On Tue, Jul 06, 2021 at 07:52:27AM +0200, Christoph Hellwig wrote:
> On Mon, Jul 05, 2021 at 06:26:03PM +0800, Ming Lei wrote:
> > +static void loop_free_idle_workers(struct work_struct *work)
> > +{
> > + struct loop_device *lo = container_of(work, struct loop_device,
> > + idle_work.work);
> > + struct loop_worker *pos, *worker;
> > +
> > + spin_lock(&lo->lo_work_lock);
> > + list_for_each_entry_safe(worker, pos, &lo->idle_worker_list,
> > + idle_list) {
> > + if (time_is_after_jiffies(worker->last_ran_at +
> > + LOOP_IDLE_WORKER_TIMEOUT))
> > + break;
> > + list_del(&worker->idle_list);
> > + rb_erase(&worker->rb_node, &lo->worker_tree);
> > + css_put(worker->blkcg_css);
> > + kfree(worker);
> > + }
> > + if (!list_empty(&lo->idle_worker_list))
> > + loop_set_timer(lo);
> > + spin_unlock(&lo->lo_work_lock);
> > +}
> > +
> > +
>
> Double empty line. But that whole fact that the loop driver badly
> reimplements work queues is just fucked up. We need to revert this
> shit.
Can you explain why work queues are bad for fixing this blkcg/memcg
issue?
Thanks,
Ming
