Re: NIU - Sun Neptune 10g - Transmit timed out reset (2.6.24)

From: Ben Hutchings
Date: Thu May 22 2008 - 13:15:53 EST

Jesper Krogh wrote:
> David Miller wrote:
> >From: Matheos Worku <Matheos.Worku@xxxxxxx>
> >Date: Fri, 09 May 2008 15:36:17 -0700
> >
> >>I have observed TX throughput degradation (and increased CPU
> >>utilization) occurs with increased # of connections, when CPU count > 4
> >>CPUs. I don't think it is related to the driver (or HW).
> >
> >All transmits through a device are fully serialized currently,
> >it's a known problem and something we plan to fix.
> I google'd up this one:
> (slide 23+).
> Does this mean that I can expect every 10G card to have this limitation
> under Linux? Or are some known to be better than others?
> (I can probably justify paying for another 10G card if I can expect to
> gain the last 400MB/s).

Our controller and driver can reach line rate for a single TCP/IPv4 stream,
depending on the host system. I don't think we're alone in that, though
there are few published benchmarks that don't involve TOEs.


Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
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