[dpdk-dev] I350 jumbo frame transmission

[dpdk-dev] I350 jumbo frame transmission

[Karthikraj palanichamy]

Hi,

I am using I350 card. The API rte_eth_dev_info_get() updated the 
parameter 'max_rx_pktlen' in 'struct rte_eth_dev_info' as 16384.

But when I try transmission with multiple segments, I could not transmit 
more than 9732 bytes.

I tried with testpmd and getting the same results.ie) couldn't transmit 
more than 9732 using testpmd.

Is this a limitation or am I missing anything?

Note : I tried with X540 card. I got 'max_rx_pktlen' as 15387 and I 
could transmit and receive upto 15387.

Thanks
Karthik

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Re: [dpdk-dev] I350 jumbo frame transmission

[Karthikraj palanichamy]

But I could receive frames upto 16384 bytes.

If 'max_rx_pktlen' is meant only for reception, then is there any way I 
could get the maximum tx capability?


On 04/12/2017 06:21 PM, Karthikraj palanichamy wrote:
> Hi,
>
> I am using I350 card. The API rte_eth_dev_info_get() updated the 
> parameter 'max_rx_pktlen' in 'struct rte_eth_dev_info' as 16384.
>
> But when I try transmission with multiple segments, I could not 
> transmit more than 9732 bytes.
>
> I tried with testpmd and getting the same results.ie) couldn't 
> transmit more than 9732 using testpmd.
>
> Is this a limitation or am I missing anything?
>
> Note : I tried with X540 card. I got 'max_rx_pktlen' as 15387 and I 
> could transmit and receive upto 15387.
>
> Thanks
> Karthik 


DISCLAIMER: Privileged and/or Confidential information may be
contained in this message. If you are not the addressee of this message,
you may not copy, use or deliver this message to anyone. In such
event,you should destroy the message and kindly notify the sender by
reply e-mail.
It is understood that opinions or conclusions that do not relate to the
official business of the company are neither given nor endorsed by the
company.

Re: [dpdk-dev] I350 jumbo frame transmission

[Bruce Richardson]

On Wed, Apr 12, 2017 at 06:21:01PM +0530, Karthikraj palanichamy wrote:
> Hi,
> 
> I am using I350 card. The API rte_eth_dev_info_get() updated the parameter
> 'max_rx_pktlen' in 'struct rte_eth_dev_info' as 16384.
> 
> But when I try transmission with multiple segments, I could not transmit
> more than 9732 bytes.
> 
> I tried with testpmd and getting the same results.ie) couldn't transmit more
> than 9732 using testpmd.
> 
> Is this a limitation or am I missing anything?
> 
> Note : I tried with X540 card. I got 'max_rx_pktlen' as 15387 and I could
> transmit and receive upto 15387.
> 
> Thanks
> Karthik
>
It seems the info returned may be wrong. According to the i350
datasheet [1], table 1-2, the max frame size supported by the i350 is
9.5k which roughly tallies with what you are seeing.

Regards,
/Bruce

[1] http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/ethernet-controller-i350-datasheet.pdf

Re: [dpdk-dev] I350 jumbo frame transmission

[Bruce Richardson]

On Wed, Apr 12, 2017 at 02:01:41PM +0100, Bruce Richardson wrote:
> On Wed, Apr 12, 2017 at 06:21:01PM +0530, Karthikraj palanichamy wrote:
> > Hi,
> > 
> > I am using I350 card. The API rte_eth_dev_info_get() updated the parameter
> > 'max_rx_pktlen' in 'struct rte_eth_dev_info' as 16384.
> > 
> > But when I try transmission with multiple segments, I could not transmit
> > more than 9732 bytes.
> > 
> > I tried with testpmd and getting the same results.ie) couldn't transmit more
> > than 9732 using testpmd.
> > 
> > Is this a limitation or am I missing anything?
> > 
> > Note : I tried with X540 card. I got 'max_rx_pktlen' as 15387 and I could
> > transmit and receive upto 15387.
> > 
> > Thanks
> > Karthik
> >
> It seems the info returned may be wrong. According to the i350
> datasheet [1], table 1-2, the max frame size supported by the i350 is
> 9.5k which roughly tallies with what you are seeing.
> 
> Regards,
> /Bruce
> 
> [1] http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/ethernet-controller-i350-datasheet.pdf

I see from your follow-up mail, that the rx_pktlen is indeed correct, in
which case, we just have a gap in not specifying the max tx pktlen, and
the data sheet is your only reference there.

/Bruce