Eric W. Biederman wrote:
> The optimized for low latency cases seem to have a strong
> market in clusters.
Clusters have captive, no, _desperate_ customers ;-) And it
seems that people are just as happy putting MPI as their
transport on top of all those link-layer technologies.
> There is one place in low latency communications that I can think
> of where TCP/IP is not the proper solution. For low latency
> communication the checksum is at the wrong end of the packet.
That's one of the few things ATM's AAL5 got right. But in the end,
I think it doesn't really matter. At 1 Gbps, an MTU-sized packet
flies by within 13 us. At 10 Gbps, it's only 1.3 us. At that point,
you may well treat it as an atomic unit.
> On that score it is worth noting that the next generation of
> peripheral busses (Hypertransport, PCI Express, etc) are all switched.
And it's about time for that :-)
- Werner
-- _________________________________________________________________________ / Werner Almesberger, Buenos Aires, Argentina werner@almesberger.net / /_http://www.almesberger.net/____________________________________________/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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