Re: [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them

[Sagi Grimberg]

> > On 8/9/21 1:52 AM, Daniel Wagner wrote:
> > > Hi Sagi,
> > >
> > > On Fri, Aug 06, 2021 at 12:57:17PM -0700, Sagi Grimberg wrote:
> > > > > -	ret = nvme_tcp_start_io_queues(ctrl);
> > > > > -	if (ret)
> > > > > -		goto out_cleanup_connect_q;
> > > > > -
> > > > > -	if (!new) {
> > > > > -		nvme_start_queues(ctrl);
> > > > > +	} else if (prior_q_cnt != ctrl->queue_count) {
> > > >
> > > > So if the queue count did not change we don't wait to make sure
> > > > the queue g_usage_counter ref made it to zero? What guarantees that it
> > > > did?
> > >
> > > Hmm, good point. we should always call nvme_wait_freeze_timeout()
> > > for !new queues. Is this what you are implying?
> >
> > I think we should always wait for the freeze to complete.
>
> Don't the queues need to be started in order for the freeze to complete?
> Any enqueued requests on the quiesced queues will never complete this
> way, so the wait_freeze() will be stuck, right? If so, I think the
> nvme_start_queues() was in the correct place already.

Exactly what I was trying to point out (poorly though)