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Subject: Re: Alan Shih: "TCP IP Offloading Interface"
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Jeff Garzik <jgarzik@pobox.com>
Cc: David griego <dagriego@hotmail.com>, alan@storlinksemi.com,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Llu, 2003-07-14 at 21:03, Jeff Garzik wrote:
> If the host CPU is a bottleneck after large-send and checksums have been 
> offloaded, then logically you aren't getting any work done _anyway_. 
> You have to interface with the net stack at some point, in which case 
> you incur a fixed cost, for socket handling, TCP exception handling, etc.
> 
> Maybe somebody needs to be looking into AMP (asymmetric 
> multiprocessing), too.

There isnt currently any evidence it buy you anything, although HT may
change that equation a bit. Its still the same RAM bandwidth and you've
not really gotten rid of most of the socket handling/event/wakeup
overhead either.