Subject: Re: Default offload settings in Ethernet drivers

From: Stephen Hemminger <[email-masked]>
Date: Thu, 11 Dec 2008 10:54:59 -0800

On Thu, 11 Dec 2008 19:41:31 +0100
Jan Ceuleers <[email-masked]> wrote:

> Hi!
> 
> A discussion recently took place on the power mailing list on the 
> subject of the impact of (hardware-assisted) offload functions on the 
> power efficiency of the overall system.
> 
> The discussion was brought on by me noticing that not all drivers enable 
>   all of their offload features by default (case in point: r8169).
> 
> Although the discussion may not be complete, early indications are that:
> 
> 1. Hardware-assisted offloads improve power efficiency unless 
> implemented in a separate CPU (TOE / Total Offloading);
> 
> 2. It would probably be a good idea to enable hardware-assisted offloads 
> other than TOE by default given the above.
> 
> I would therefore like to sollicit views here:
> 
> 1. Would changing default offload settings in Ethernet drivers help to 
> save the planet?
> 
> 2. Which offload settings does it make sense to enable by default?

Go get a kill-a-watt meter and real hardware and measure.
I don't think there will be any difference. Linux (mainline) doesn't
do TOE. It does do segmentation offload, and any driver that can
do segmentation offload enables it by default.