netdev - Re: [PATCH net-next 0/5] qed/qede: Tunnel hardware GRO support

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Date:	Wed, 22 Jun 2016 16:52:25 -0700
From:	Rick Jones <rick.jones2@....com>
To:	Alexander Duyck <alexander.duyck@...il.com>,
	Eric Dumazet <eric.dumazet@...il.com>
Cc:	Yuval Mintz <Yuval.Mintz@...gic.com>,
	Manish Chopra <manish.chopra@...gic.com>,
	David Miller <davem@...emloft.net>,
	netdev <netdev@...r.kernel.org>,
	Ariel Elior <Ariel.Elior@...gic.com>,
	Tom Herbert <tom@...bertland.com>,
	Hannes Frederic Sowa <hannes@...hat.com>
Subject: Re: [PATCH net-next 0/5] qed/qede: Tunnel hardware GRO support

On 06/22/2016 03:56 PM, Alexander Duyck wrote:
> On Wed, Jun 22, 2016 at 3:47 PM, Eric Dumazet <eric.dumazet@...il.com> wrote:
>> On Wed, 2016-06-22 at 14:52 -0700, Rick Jones wrote:
>>> Had the bnx2x-driven NICs' firmware not had that rather unfortunate
>>> assumption about MSSes I probably would never have noticed.

> It could be that you and Rick are running different firmware. I
> believe you can expose that via "ethtool -i".  This is the ugly bit
> about all this.  We are offloading GRO into the firmware of these
> devices with no idea how any of it works and by linking GRO to LRO on
> the same device you are stuck having to accept either the firmware
> offload or nothing at all.  That is kind of the point Rick was trying
> to get at.

I think you are typing a bit too far ahead into my keyboard with that 
last sentence.  And I may not have been sufficiently complete in what I 
wrote.  If the bnx2x-driven NICs' firmware had been coalescing more than 
two segments together, not only would I probably not have noticed, I 
probably would not have been upset to learn it was NIC-firmware GRO 
rather than stack.

My complaint is the specific bug of coalescing only two segments when 
their size is unexpected, and the difficulty present in disabling the 
bnx2x-driven NICs' firmware GRO.  I don't have a problem necessarily 
with the existence of NIC-firmware GRO in general.  I just want to be 
able to enable/disable it easily.

rick jones

Of course, what I really want are much, Much, MUCH larger MTUs.  It 
isn't for nothing that I used to refer to TSO as "Poor man's Jumbo 
Frames" :)