Subject: Re: [PATCH net-next 0/6] tcp: remove non GSO code

From: Oleksandr Natalenko <[email-masked]>
Date: Tue, 20 Feb 2018 21:45:23 +0100

On úterý 20. února 2018 21:09:37 CET Eric Dumazet wrote:
> Also you can tune your NIC to accept few MSS per GSO/TSO packet
> 
> ip link set dev eth0 gso_max_segs 2
> 
> So even if TSO/GSO is there, BBR should not use sk->sk_gso_max_segs to
> size its bursts, since burt sizes are also impacting GRO on the
> receiver.

net-next + 7 patches (6 from the patchset + this one).

Before playing with gso_max_segs:

BBR+fq
sg on:  4.39 Gbits/sec
sg off: 1.33 Gbits/sec

BBR+fq_codel
sg on:  4.02 Gbits/sec
sg off: 1.41 Gbits/sec

BBR+pfifo_fast
sg on:  3.66 Gbits/sec
sg off: 1.41 Gbits/sec

Reno+fq
sg on:  5.69 Gbits/sec
sg off: 1.53 Gbits/sec

Reno+fq_codel
sg on:  6.33 Gbits/sec
sg off: 1.50 Gbits/sec

Reno+pfifo_fast
sg on:  6.26 Gbits/sec
sg off: 1.48 Gbits/sec

After "ip link set dev eth1 gso_max_segs 2":

BBR+fq
sg on:  806 Mbits/sec
sg off: 886 Mbits/sec

BBR+fq_codel
sg on:  206 Mbits/sec
sg off: 207 Mbits/sec

BBR+pfifo_fast
sg on:  220 Mbits/sec
sg off: 200 Mbits/sec

Reno+fq
sg on:  2.16 Gbits/sec
sg off: 1.27 Gbits/sec

Reno+fq_codel
sg on:  2.45 Gbits/sec
sg off: 1.52 Gbits/sec

Reno+pfifo_fast
sg on:  2.31 Gbits/sec
sg off: 1.54 Gbits/sec

Oleksandr