[RFC] Patch to add Software/Generic Segmentation Offload (GSO) support in FreeBSD

[Stefano Garzarella]

Hi Hans,
I saw the discussion about TSO, but the GSO is a software
implementation unrelated with the hardware.
Furthermore, if the TSO is enabled (and supported by the NIC), the GSO is
not executed, because is useless.

After the execution of the GSO, the packets, that are passed to the device
driver, are smaller (or equal) than MTU, so the TSO is unnecessary. For
this reason the GSO doesn't look neither "ifp->if_hw_tsomax" nor hardware
segment limits.

The GSO is very useful when you can't use the TSO.

Cheers,
Stefano

2014-09-17 22:27 GMT+02:00 Hans Petter Selasky <hps at selasky.org>:

> On 09/17/14 20:18, Stefano Garzarella wrote:
>
>> Hi Adrian,
>> the results that I sent, regard just one flow, but I can try with two
>> simultaneous flows and I'll send you the results.
>>
>> Thanks,
>> Stefano
>>
>>
> Hi Stefano,
>
> You might have seen the discussion about TSO. Is it so that the proposed
> GSO feature only looks at the "ifp->if_hw_tsomax" field, and ignores
> hardware limits regarding maximum segment size and maximum segment count?
>
> --HPS
>



-- 
*Stefano Garzarella*
stefano.garzarella at gmail.com