From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Monjalon <thomas.monjalon@6wind.com>
Subject: Re: mbuf changes
Date: Tue, 25 Oct 2016 16:54:29 +0200
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Cc: dev@dpdk.org, Olivier Matz <olivier.matz@6wind.com>,
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To: "Ramia, Kannan Babu" <kannan.babu.ramia@intel.com>
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2016-10-25 14:32, Ramia, Kannan Babu:
> I didn't get your question. The only information exchanged between th=
e stages is mbuf pointer. So the information has to be in mbuf, whether=
 it's part of Meta or in private area in the packet buffer headroom is =
that the question you are asking. The private area is application speci=
fic, while I am looking for the port information getting updated from d=
river to application and it's generic to multiple applications.=20

Thanks, your answer is perfect (except it is top-posted ;)

The discussion is more about performance. So you agree that the port
information is not performance sensitive.
It appears that it could be an information filled in a private area
at app-level, because the application knows which port it is polling.
However we may need a way to put some generic informations somewhere,
not in the first cache lines.


> -----Original Message-----
> From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com]=20
> Sent: Tuesday, October 25, 2016 6:54 PM
> To: Ramia, Kannan Babu <kannan.babu.ramia@intel.com>
> Cc: dev@dpdk.org; Olivier Matz <olivier.matz@6wind.com>; Morten Br=F8=
rup <mb@smartsharesystems.com>; Ananyev, Konstantin <konstantin.ananyev=
@intel.com>; Richardson, Bruce <bruce.richardson@intel.com>; Wiles, Kei=
th <keith.wiles@intel.com>
> Subject: Re: [dpdk-dev] mbuf changes
>=20
> 2016-10-25 13:04, Ramia, Kannan Babu:
> > Port filed is important meta information for the application use li=
ke=20
> > CGNAT vEPC functions etc.
> > I strongly recommend to keep the field in mind meta.
>=20
> Have you tried to move this field outside of the mbuf?
> What is the performance degradation?
> We need more information than some assumptions.
>=20