Re: [dpdk-dev] [PATCH] ethdev: warn only once for badly behaving applications

[David Marchand <david.marchand@redhat.com>]

On Tue, Oct 26, 2021 at 7:10 PM Ananyev, Konstantin
<konstantin.ananyev@intel.com> wrote:
> >  static uint16_t
> > -dummy_eth_rx_burst(__rte_unused void *rxq,
> > +dummy_eth_rx_burst(void *rxq,
> >               __rte_unused struct rte_mbuf **rx_pkts,
> >               __rte_unused uint16_t nb_pkts)
> >  {
> > -     RTE_ETHDEV_LOG(ERR, "rx_pkt_burst for not ready port\n");
> > +     struct dummy_queue *q = rxq;
> > +
>
> LGTM in general, just one thing:
> I think we'd better add extra check that rxq really points to dummy queues
> before de-referencing it.
> Something like:
>
> uintptr_t port_id;
> ....
> port_id =  q - dummy_queues;
> if (port_id < RTE_DIM(dummy_queues) && !q->rx_warn_once) {
>    ....
> }
>
> Same for tx.

Yep, will add.


>
> > +     if (!q->rx_warn_once) {
> > +             uint16_t port_id = q - dummy_queues;
> > +
> > +             RTE_ETHDEV_LOG(ERR, "lcore %u called rx_pkt_burst for not ready port %"PRIu16"\n",
> > +                     rte_lcore_id(), port_id);
> > +             rte_dump_stack();
> > +             q->rx_warn_once = true;
> > +     }
> >       rte_errno = ENOTSUP;
> >       return 0;
> >  }
> >
> >  static uint16_t
> > -dummy_eth_tx_burst(__rte_unused void *txq,
> > +dummy_eth_tx_burst(void *txq,
> >               __rte_unused struct rte_mbuf **tx_pkts,
> >               __rte_unused uint16_t nb_pkts)
> >  {
> > -     RTE_ETHDEV_LOG(ERR, "tx_pkt_burst for not ready port\n");
> > +     struct dummy_queue *q = txq;
> > +
> > +     if (!q->tx_warn_once) {
> > +             uint16_t port_id = q - dummy_queues;
> > +
> > +             RTE_ETHDEV_LOG(ERR, "lcore %u called tx_pkt_burst for not ready port %"PRIu16"\n",
> > +                     rte_lcore_id(), port_id);
> > +             rte_dump_stack();
> > +             q->tx_warn_once = true;
> > +     }
> >       rte_errno = ENOTSUP;
> >       return 0;
> >  }
> > @@ -199,14 +236,22 @@ void
> >  eth_dev_fp_ops_reset(struct rte_eth_fp_ops *fpo)
> >  {
> >       static void *dummy_data[RTE_MAX_QUEUES_PER_PORT];
> > -     static const struct rte_eth_fp_ops dummy_ops = {
> > +     uint16_t port_id = fpo - rte_eth_fp_ops;
> > +
> > +     dummy_queues[port_id].rx_warn_once = false;
> > +     dummy_queues[port_id].tx_warn_once = false;
> > +     *fpo = (struct rte_eth_fp_ops) {
> >               .rx_pkt_burst = dummy_eth_rx_burst,
> >               .tx_pkt_burst = dummy_eth_tx_burst,
> > -             .rxq = {.data = dummy_data, .clbk = dummy_data,},
> > -             .txq = {.data = dummy_data, .clbk = dummy_data,},
> > +             .rxq = (struct rte_ethdev_qdata) {
>
> Here and for txq, do we need to explicitly specify type?
> Wouldn't:
> .rxq = {.data=..., .clbk=...,},
> be enough here?

Well, same question from Thomas.
It seems to work without it.


-- 
David Marchand