Re: [dpdk-dev] [PATCH v3 1/4] mbuf:add three TX offload flags and change three fields

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> -----Original Message-----
> From: Olivier MATZ [mailto:olivier.matz@6wind.com]
> Sent: Friday, November 28, 2014 11:00 AM
> To: Ananyev, Konstantin; Liu, Jijiang; dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v3 1/4] mbuf:add three TX offload flags and change three fields
> 
> Hi Konstantin,
> 
> On 11/28/2014 11:40 AM, Ananyev, Konstantin wrote:
> >
> > Well, I still prefer them to be mutually exclusive.
> > Even better, if we can squeeze these 3 flags into 2 bits.
> > Would save us 2 bits, plus might be handy, as in the PMD you can do:
> >
> > switch (ol_flags & TX_L3_MASK) {
> >     case TX_IPV4:
> >        ...
> >        break;
> >     case TX_IPV6:
> >        ...
> >        break;
> >     case TX_IP_CKSUM:
> >        ...
> >        break;
> > }
> >
> > For the upper layer, I think there would be no big difference, what ways we will choose.
> 
> I think the 2 informations are transversal, and that's why I would
> prefer 2 flags. Also, having 2 separate flags would also help to keep
> backward compatibility with previous versions.

Hmm, not sure how we will break compatibility in that case?
If we'll make TX_IP_CKSUM to be 1 bit value (1 << X) then for current drivers nothing should change, no?

> 
> It may help to have other points of view to make the good decision.
> I'll follow the majority.
> 
> Regards,
> Olivier