On Tue, Oct 25, 2022 at 09:11:37PM -0600, Keith Busch wrote:
> On Wed, Oct 26, 2022 at 09:55:21AM +0800, Ming Lei wrote:
> > @@ -1564,8 +1571,13 @@ static bool blk_mq_check_expired(struct request *rq, void *priv)
> > * it was completed and reallocated as a new request after returning
> > * from blk_mq_check_expired().
> > */
> > - if (blk_mq_req_expired(rq, next))
> > + if (blk_mq_req_expired(rq, expired)) {
> > + if (expired->check_only) {
> > + expired->has_timedout_rq = true;
> > + return false;
> > + }
> > blk_mq_rq_timed_out(rq);
> > + }
> > return true;
> > }
> >
> > @@ -1573,7 +1585,10 @@ static void blk_mq_timeout_work(struct work_struct *work)
> > {
> > struct request_queue *q =
> > container_of(work, struct request_queue, timeout_work);
> > - unsigned long next = 0;
> > + struct blk_expired_data expired = {
> > + .check_only = true,
> > + .timeout_start = jiffies,
> > + };
> > struct blk_mq_hw_ctx *hctx;
> > unsigned long i;
> >
> > @@ -1593,10 +1608,24 @@ static void blk_mq_timeout_work(struct work_struct *work)
> > if (!percpu_ref_tryget(&q->q_usage_counter))
> > return;
> >
> > - blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &next);
> > + /* check if there is any timed-out request */
> > + blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &expired);
> > + if (expired.has_timedout_rq) {
> > + /*
> > + * Before walking tags, we must ensure any submit started
> > + * before the current time has finished. Since the submit
> > + * uses srcu or rcu, wait for a synchronization point to
> > + * ensure all running submits have finished
> > + */
> > + blk_mq_wait_quiesce_done(q);
> > +
> > + expired.check_only = false;
> > + expired.next = 0;
> > + blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &expired);
>
> I think it would be easier to follow with separate callbacks instead of
> special casing for 'check_only'. One callback for checking timeouts, and
> a different one for handling them?
Both two are basically same, with two callbacks, just .check_only is saved,
nothing else, meantime with one extra similar callback added.
If you or anyone think it is one big deal, I can switch to two callback version.
Thanks,
Ming
