[ofa-general] [PATCH 13 of 17]: add LRO support

[Or Gerlitz]

Eli Cohen wrote:
> Add Large Receive Offload support to IPOIB
> 
> Reduce overhead incurred by handling many small packets
> by aggregating SKBs related to the same stream and passing
> them up. This patch is based on the work done for MTNIC
> by Liran Liss <liranl at mellanox.co.il>

Hi Eli,

Back on April a user having the configuration

A --- 10g --- B --- IB --- C

where node B acts as an IP router having one 10g interface
and one IB interface reported on a sever bandwidth problem
which was resolved to be related to the 10g driver have LRO mechanism 
which is not operative under forwarding scheme, see the email/thread 
http://lists.openfabrics.org/pipermail/general/2007-April/035322.html

My question is, does the suggested LRO code need to be disabled when the 
node does forwarding?

Indeed you have removed the LSO, LRO patches from the stateless offload 
patch set posting to the upstream kernel, but they do exist in OFED 1.3

Tziporet - I am quite worried from distributing with OFED 1.3 ipoib 
changes (namely LSO and LRO support) which were never reviewed by the 
community and that I understand are not planned for review towards 2.6.24.

What is your thinking on the matter?

Or.

> -----Original Message-----
> From: general-bounces at lists.openfabrics.org On Behalf Of David Miller
> Sent: Saturday, April 28, 2007 2:40 AM
> To: rick.jones2 at hp.com
> Cc: lawver1 at llnl.gov; netdev at vger.kernel.org; mst at dev.mellanox.co.il; general at lists.openfabrics.org
> Subject: Re: [ofa-general] Re: IPoIB forwarding
> 
> From: Rick Jones <rick.jones2 at hp.com>
> Date: Fri, 27 Apr 2007 16:37:49 -0700
> 
>> Large Receive Offload (LRO) is enabled by default.  This will 
>> interfere with forwarding TCP traffic.  If you plan to forward TCP 
>> traffic (using the host with the Myri10GE NIC as a router or bridge), 
>> you must disable LRO.  To disable LRO, load the myri10ge driver with 
>> myri10ge_lro set to 0:
> 
> LRO should be disabled by default if the driver does this.  This is a major and unacceptable bug.
> 
> Thanks for pointing this out Rick.