Re: linux-next network throughput performance regression

From: Eric Dumazet
Date: Mon Nov 09 2015 - 18:04:47 EST

On Mon, 2015-11-09 at 20:23 +0000, Simon Xiao wrote:
> Thanks Eric to provide the data. I am looping Tom (as I am looking into his recent patches) and Olaf (from Suse).
> So, if I understand it correctly, you are running netperf with single
> TCP connection, and you got ~26Gbps initially and got ~30Gbps after
> turning the tx-usecs and tx-frames.
> Do you have a baseline on your environment for the best/max/or peak
> throughput?

The peak on my lab pair is about 34Gbits, usually I get this if I pin
the receiving thread on a cpu, otherwise process scheduler can really
hurt too much.

lpaa23:~# DUMP_TCP_INFO=1 ./netperf -H lpaa24 -l 20 -Cc -T ,1
MIGRATED TCP STREAM TEST from ( port 0 AF_INET to () port 0 AF_INET : cpu bind
tcpi_rto 201000 tcpi_ato 0 tcpi_pmtu 1500 tcpi_rcv_ssthresh 29200
tcpi_rtt 101 tcpi_rttvar 15 tcpi_snd_ssthresh 289 tpci_snd_cwnd 289
tcpi_reordering 3 tcpi_total_retrans 453
Recv Send Send Utilization Service Demand
Socket Socket Message Elapsed Send Recv Send Recv
Size Size Size Time Throughput local remote local remote
bytes bytes bytes secs. 10^6bits/s % S % S us/KB us/KB

87380 16384 16384 20.00 33975.99 1.27 3.36 0.147 0.389

Not too bad, I don't recall reaching more than that ever.

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