Re: [dpdk-dev] [PATCH v4 3/6] app/testpmd: remove restriction on txpkts set

[Slava Ovsiienko <viacheslavo@nvidia.com>]

The bug: https://bugs.dpdk.org/show_bug.cgi?id=584

Can we pass the nb_segs = 1 always? 
One descriptor is minimal basic capability to send, it should be always supported.

With best regards, Slava

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@intel.com>
> Sent: Wednesday, November 25, 2020 16:07
> To: NBU-Contact-Thomas Monjalon <thomas@monjalon.net>; Wei Hu (Xavier)
> <huwei013@chinasoftinc.com>
> Cc: dev@dpdk.org; xavier.huwei@huawei.com; Slava Ovsiienko
> <viacheslavo@nvidia.com>
> Subject: Re: [dpdk-dev] [PATCH v4 3/6] app/testpmd: remove restriction on
> txpkts set
> 
> On 11/24/2020 12:23 PM, Ferruh Yigit wrote:
> > On 11/24/2020 10:27 AM, Thomas Monjalon wrote:
> >> Is it OK to keep this regression?
> >>
> >> Ferruh, what do you suggest?
> >>
> >
> > I confirm the '--txpkts' parameter is broken now, I suggest submitting
> > a defect for it and continue with the regression.
> >
> 
> Hi Slava,
> 
> Can you please submit the Bugzilla defect?
> 
> Thanks,
> ferruh
> 
> 
> > We have alternative for the parameter, "set txpkts <len0[,len1]*>" command.
> > The parameter was only working when hardcoded '--txd=N' parameter is
> > provided, the command is more dynamic and works however queue size is
> configured.
> >
> > We can fix the '--txpkts' in next release.
> >
> >>
> >> 23/11/2020 12:50, Slava Ovsiienko:
> >>> Hi,  Wei
> >>>
> >>> It was found this patch rejects the --txpkts command line settings.
> >>> set_tx_pkt_segments() is called before device started and we have
> >>> failure chain:
> >>>
> >>> set_tx_pkt_segments()
> >>>    nb_segs_is_invalid()
> >>>      get_tx_ring_size ()
> >>>       rte_eth_tx_queue_info_get()
> >>>
> >>> It causes --txpkts testpmd command line option is ignored.
> >>>
> >>> With best regards, Slava
> >>>
> >>>> -----Original Message-----
> >>>> From: dev <dev-bounces@dpdk.org> On Behalf Of Wei Hu (Xavier)
> >>>> Sent: Friday, September 25, 2020 15:47
> >>>> To: dev@dpdk.org
> >>>> Cc: xavier.huwei@huawei.com
> >>>> Subject: [dpdk-dev] [PATCH v4 3/6] app/testpmd: remove restriction
> >>>> on txpkts set
> >>>>
> >>>> From: Chengchang Tang <tangchengchang@huawei.com>
> >>>>
> >>>> Currently, if nb_txd is not set, the txpkts is not allowed to be
> >>>> set because the nb_txd is used to avoid the numer of segments
> >>>> exceed the Tx ring size and the default value of nb_txd is 0. And
> >>>> there is a bug that nb_txd is the global configuration for Tx ring
> >>>> size and the ring size could be changed by some command per queue.
> >>>> So these valid check is unreliable and introduced unnecessary
> >>>> constraints.
> >>>>
> >>>> This patch adds a valid check function to use the real Tx ring size
> >>>> to check the validity of txpkts.
> >>>>
> >>>> Fixes: af75078fece3 ("first public release")
> >>>> Cc: stable@dpdk.org
> >>>>
> >>>> Signed-off-by: Chengchang Tang <tangchengchang@huawei.com>
> >>>> Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
> >>>> ---
> >>>> v3 -> v4:
> >>>>      add check 'rte_eth_rx_queue_info_get()' return value and
> >>>>      if it is '-ENOSTUP' calculate the 'ring_size'.
> >>>> v3:      initial version.
> >>>> ---
> >>>>   app/test-pmd/config.c | 64
> >>>> +++++++++++++++++++++++++++++++++++++++++++++++----
> >>>>   1 file changed, 60 insertions(+), 4 deletions(-)
> >>>>
> >>>> diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c index
> >>>> 6496d2f..8ebb927 100644
> >>>> --- a/app/test-pmd/config.c
> >>>> +++ b/app/test-pmd/config.c
> >>>> @@ -1893,6 +1893,38 @@ tx_queue_id_is_invalid(queueid_t txq_id)  }
> >>>>
> >>>>   static int
> >>>> +get_tx_ring_size(portid_t port_id, queueid_t txq_id, uint16_t
> >>>> +*ring_size) {
> >>>> +    struct rte_port *port = &ports[port_id];
> >>>> +    struct rte_eth_txq_info tx_qinfo;
> >>>> +    int ret;
> >>>> +
> >>>> +    ret = rte_eth_tx_queue_info_get(port_id, txq_id, &tx_qinfo);
> >>>> +    if (ret == 0) {
> >>>> +        *ring_size = tx_qinfo.nb_desc;
> >>>> +        return ret;
> >>>> +    }
> >>>> +
> >>>> +    if (ret != -ENOTSUP)
> >>>> +        return ret;
> >>>> +    /*
> >>>> +     * If the rte_eth_tx_queue_info_get is not support for this
> >>>> +PMD,
> >>>> +     * ring_size stored in testpmd will be used for validity verification.
> >>>> +     * When configure the txq by rte_eth_tx_queue_setup with
> >>>> nb_tx_desc
> >>>> +     * being 0, it will use a default value provided by PMDs to
> >>>> +setup this
> >>>> +     * txq. If the default value is 0, it will use the
> >>>> +     * RTE_ETH_DEV_FALLBACK_TX_RINGSIZE to setup this txq.
> >>>> +     */
> >>>> +    if (port->nb_tx_desc[txq_id])
> >>>> +        *ring_size = port->nb_tx_desc[txq_id];
> >>>> +    else if (port->dev_info.default_txportconf.ring_size)
> >>>> +        *ring_size = port->dev_info.default_txportconf.ring_size;
> >>>> +    else
> >>>> +        *ring_size = RTE_ETH_DEV_FALLBACK_TX_RINGSIZE;
> >>>> +    return 0;
> >>>> +}
> >>>> +
> >>>> +static int
> >>>>   rx_desc_id_is_invalid(uint16_t rxdesc_id)  {
> >>>>       if (rxdesc_id < nb_rxd)
> >>>> @@ -2986,17 +3018,41 @@ show_tx_pkt_segments(void)
> >>>>       printf("Split packet: %s\n", split);
> >>>>   }
> >>>>
> >>>> +static bool
> >>>> +nb_segs_is_invalid(unsigned int nb_segs) {
> >>>> +    uint16_t ring_size;
> >>>> +    uint16_t queue_id;
> >>>> +    uint16_t port_id;
> >>>> +    int ret;
> >>>> +
> >>>> +    RTE_ETH_FOREACH_DEV(port_id) {
> >>>> +        for (queue_id = 0; queue_id < nb_txq; queue_id++) {
> >>>> +            ret = get_tx_ring_size(port_id, queue_id, &ring_size);
> >>>> +
> >>>> +            if (ret)
> >>>> +                return true;
> >>>> +
> >>>> +            if (ring_size < nb_segs) {
> >>>> +                printf("nb segments per TX packets=%u >= "
> >>>> +                       "TX queue(%u) ring_size=%u - ignored\n",
> >>>> +                       nb_segs, queue_id, ring_size);
> >>>> +                return true;
> >>>> +            }
> >>>> +        }
> >>>> +    }
> >>>> +
> >>>> +    return false;
> >>>> +}
> >>>> +
> >>>>   void
> >>>>   set_tx_pkt_segments(unsigned *seg_lengths, unsigned nb_segs)  {
> >>>>       uint16_t tx_pkt_len;
> >>>>       unsigned i;
> >>>>
> >>>> -    if (nb_segs >= (unsigned) nb_txd) {
> >>>> -        printf("nb segments per TX packets=%u >= nb_txd=%u -
> >>>> ignored\n",
> >>>> -               nb_segs, (unsigned int) nb_txd);
> >>>> +    if (nb_segs_is_invalid(nb_segs))
> >>>>           return;
> >>>> -    }
> >>>>
> >>>>       /*
> >>>>        * Check that each segment length is greater or equal than
> >>>> --
> >>>> 2.9.5
> >>>
> >>>
> >>
> >>
> >>
> >>
> >>
> >