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

From: Jesper Krogh
Date: Thu May 22 2008 - 12:32:37 EST

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).

Since I cannot push more than ~600MB/s through the NIC before a single cpu is bottlenecked, it seem most likely to be this TX throughput
thing I hit.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at