Re: More performance for the TCP stack by using additional hardware chip on NIC

[Avi Kivity <avi@argo.co.il>]

On Sun, 2005-04-17 at 12:07, Arjan van de Ven wrote:
> On Sun, 2005-04-17 at 10:17 +0200, Andreas Hartmann wrote:
> > Hello!
> > 
> > Alacritech developed a new chip for NIC's
> > (http://www.alacritech.com/html/tech_review.html), which makes it possible
> > to take away the TCP stack from the host CPU. Therefore, the host CPU has
> > more performance for the applications according Alacritech.
> 
> there are very many good reasons why this for linux is not the right
> solution, including the fact that the linux tcp/ip stack already is
> quite fast so the "gains" achieved aren't that stellar as the gains you
> get when comparing to windows.
> 

TOEs can remove the data copy on receive. In some applications (notably
storage), where the application does not touch most of the data, this is
a significant advantage that cannot be achieved in a software-only
solution.


> Also these types of solution always add quite a bit of overhead to
> connection setup/teardown making it actually a *loss* for the "many
> short connections" types of workloads. Now guess which things certain
> benchmarks use, and guess what real world servers do :)
> 

again, this depends on the application.

a copyless solution is probably necessary to achieve 10Gb/s speeds.

Avi