On 2018-03-13 21:10:39 [+0100], Peter Zijlstra wrote:
> On Tue, Mar 13, 2018 at 07:42:41PM +0100, Sebastian Andrzej Siewior wrote:
> > +static void blk_queue_usage_counter_release_swork(struct swork_event *sev)
> > +{
> > + struct request_queue *q =
> > + container_of(sev, struct request_queue, mq_pcpu_wake);
> > +
> > + wake_up_all(&q->mq_freeze_wq);
> > +}
> > +
> > static void blk_queue_usage_counter_release(struct percpu_ref *ref)
> > {
> > struct request_queue *q =
> > container_of(ref, struct request_queue, q_usage_counter);
> >
> > - wake_up_all(&q->mq_freeze_wq);
> > + swork_queue(&q->mq_pcpu_wake);
> > }
>
> Depending on if we expect there to actually be wakeups, you could do
> something like:
>
> if (wq_has_sleepers(&q->mq_freeze_wq))
> swork_queue(&q->mq_pcpu_wake));
>
> avoiding the whole workqueue thing in the case there wasn't anybody
> waiting for it. But since I don't know this code, I can't say if it
> makes sense or not. Tejun?
this pops up on boot and shows that there are no waiter. So I consider
to take this.
Sebastian
