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Re: tcp/ip performance on ecos
On Mon, Mar 11, 2002 at 07:07:53PM -0700, Gary Thomas wrote:
> On Mon, 2002-03-11 at 18:44, Yong wrote:
> >
> > can anyone tell me how much cpu resource(mips) is needed to run tcpip stack
> > on ecos nonstop ? I am planning to make my board a video stream server on
> > 100M lan enviroment ,but concerned about overall performance of the system,
> > my board is based on hitachi sh-3 cpu which is about 60 mips .
> >
>
> The networking performance depends on many factors, not only the CPU
> and it's speed. Probably the most important is the actual networking
> adapter itself - some require much more overhead than others do.
With a little profiling, it may be possible to improve things
dramatically. I re-wrote the IP checksum routine in ARM
assembly and reduced the network stack CPU usage by almost 50%.
Like Gary said, there can be a huge difference from one
Ethernet controller to another. Worst case: no DMA and
Ethernet CRCs in software (don't laugh, I've had to do it).
OTOH, if you've got an Ethernet controller that can do
scatter/gather DMA and IP checksums in hardware, the thing is
going to fly.
--
Grant Edwards
grante@visi.com
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