From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: netdev@vger.kernel.org
Subject: Poor IPv6 TCP performance in 4.3-rc3
Date: Wed, 30 Sep 2015 00:32:53 +0100 [thread overview]
Message-ID: <20150929233253.GS21513@n2100.arm.linux.org.uk> (raw)
Hi,
I'm seeing really poor IPv6 performance compared to IPv4. I've
checked using two different ARM platforms - an iMX6 platform using
the FEC driver, and an Armada 38x using mvneta.
The following was captured using iperf between the target system
and my laptop. The problem only occurs one-way. The 4.3-rc3
platform is running iperf in server mode, the laptop is in client
mode.
Armada 38x:
ipv6: [ 4] 0.0-23.9 sec 170 KBytes 58.3 Kbits/sec
ipv4: [ 4] 0.0-10.0 sec 1.09 GBytes 936 Mbits/sec
iMX6Q:
ipv6: [ 4] 0.0-11.1 sec 640 KBytes 474 Kbits/sec
ipv4: [ 4] 0.0-10.0 sec 655 MBytes 549 Mbits/sec
iMX6D with 4.2:
ipv6: [ 4] 0.0-10.0 sec 685 MBytes 574 Mbits/sec
ipv4: [ 4] 0.0-10.0 sec 696 MBytes 583 Mbits/sec
It looks like there's an IPv6 regression between 4.2 and 4.3-rc3.
Turning GRO off on Armada 38x gives:
ipv6: [ 4] 0.0-10.0 sec 1.08 GBytes 923 Mbits/sec
ipv4: [ 5] 0.0-10.0 sec 1.09 GBytes 936 Mbits/sec
I haven't started to debug yet, but I thought I'd post a heads-up in
case it's a known problem. I'll try to get some packet logs on
Thursday, and I'll try to bisect.
--
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.
next reply other threads:[~2015-09-29 23:32 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-29 23:32 Russell King - ARM Linux [this message]
2015-09-29 23:40 ` Poor IPv6 TCP performance in 4.3-rc3 Fabio Estevam
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