Re: [PATCH v5] net: ethernet: add driver for Aurora VLSI NB8800 Ethernet controller

From: Måns Rullgård
Date: Wed Nov 11 2015 - 09:15:38 EST

Eric Dumazet <eric.dumazet@xxxxxxxxx> writes:

> On Wed, 2015-11-11 at 13:48 +0000, Måns Rullgård wrote:
>> Eric Dumazet <eric.dumazet@xxxxxxxxx> writes:
>> > On Wed, 2015-11-11 at 13:04 +0000, Måns Rullgård wrote:
>> >
>> >> I tried that, and throughput (as measured by iperf3) dropped by 2%.
>> >> Maybe I did something wrong.
>> >
>> > What link speed have you used, what was the throughput you got,
>> > and is the receiver using the same NIC ?
>> 1Gbps link, 640 Mbps TCP transmit throughput to a PC with Intel NIC.
>> Why does it matter what NIC the receiver has?
> Because at 1Gb line rate, you better get GRO properly implemented in the
> receiver, so that TCP stack does not send one ACK every 2 MSS.
> Send speed is also dependent on the number of ACK packets the sender has
> to process.
> This is why I suggested you use napi_gro_receive() in your driver.

FWIW, with UDP I get 650 Mbps.

Måns Rullgård
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