Re: InfiniBand BOF @ LSM - topics of interest

Jakob Østergaard (jakob@unthought.net)
Wed, 15 May 2002 01:25:00 +0200


On Tue, May 14, 2002 at 01:19:13PM -0700, Tony.P.Lee@nokia.com wrote:
...
>
> I like to see user application such as VNC, SAMBA build directly
> on top of IB API. I have couple of IB cards that can
> send 10k 32KBytes message (320MB of data) every ~1 second over
> 1x link with only <7% CPU usage (single CPU xeon 700MHz).
> I was very impressed.
>
> Go thru the socket layer API would just slow thing down.

Not going thru the socket layer will slow you down even more. It will require
you to re-write every single performance-requiring application every time some
bloke designs a new network interconnect with a new API.

I'd take a 5% performance loss over re-writing all my code any day.

But why would it be any slower going over the socket API ? After all, quite a
lot of people have put quite a lot of effort into making that API perform very
well.

>
> With IB bandwidth faster than standard 32/33MHZ PCI, one might
> run DOOM over VNC over IB on remote computer faster
> than a normal PC running DOOM locally....

But not until you port DOOM to the API-of-the-day. Sweet idea though ;)

>
> One might create a OS that miror the complete process state
> info (replicate all the modified page) everytime that
> process is schedule out.

Latency kills.

Adding tracks to the highway doesn't make it any shorter.

-- 
................................................................
:   jakob@unthought.net   : And I see the elder races,         :
:.........................: putrid forms of man                :
:   Jakob Østergaard      : See him rise and claim the earth,  :
:        OZ9ABN           : his downfall is at hand.           :
:.........................:............{Konkhra}...............:
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