From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rick Jones Subject: Re: [Bugme-new] [Bug 11752] New: Extremely low netperf UDP_RR throughput for nvidia MCP65 Date: Fri, 17 Oct 2008 14:05:28 -0700 Message-ID: <48F8FE18.6060005@hp.com> References: <20081016134920.1492cdcc.akpm@linux-foundation.org> <48F7AD1A.7050309@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: Andrew Morton , netdev@vger.kernel.org, bugme-daemon@bugzilla.kernel.org, Ayaz Abdulla To: "Arno J. Klaassen" Return-path: Received: from g5t0008.atlanta.hp.com ([15.192.0.45]:5225 "EHLO g5t0008.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753659AbYJQVFe (ORCPT ); Fri, 17 Oct 2008 17:05:34 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: Arno J. Klaassen wrote: > Hello, > > >>Are netstat stats showing retransmissions during a TCP_STREAM test? > > > some more info : > > [root@localhost mcp65]# uname -a > Linux localhost.localdomain 2.6.27-0.352.rc7.git1.fc10.x86_64 #1 SMP Tue Sep 23 21:13:29 EDT 2008 x86_64 x86_64 x86_64 GNU/Linux > > > [root@localhost ~]# ifconfig > eth0 Link encap:Ethernet HWaddr 00:1E:68:XXX > inet addr:172.16.1.31 Bcast:172.16.1.255 Mask:255.255.255.0 > inet6 addr: XXX/64 Scope:Link > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > RX packets:1731 errors:149 dropped:0 overruns:0 frame:149 > TX packets:1628 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:1000 > RX bytes:2549871 (2.4 MiB) TX bytes:125378 (122.4 KiB) > Interrupt:20 Base address:0x6000 > > After some fiddling (essentially installing a netperf-rpm) : > > [root@localhost mcp65]# netstat -Ieth0 > Kernel Interface table > Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg > eth0 1500 0 6347 508 0 0 5838 0 0 0 BMRU > > > [root@localhost mcp65]# ethtool eth0 > Settings for eth0: > Supported ports: [ MII ] > Supported link modes: 10baseT/Half 10baseT/Full > 100baseT/Half 100baseT/Full > 1000baseT/Full > Supports auto-negotiation: Yes > Advertised link modes: 10baseT/Half 10baseT/Full > 100baseT/Half 100baseT/Full > 1000baseT/Full > Advertised auto-negotiation: Yes > Speed: 1000Mb/s > Duplex: Full > Port: MII > PHYAD: 1 > Transceiver: external > Auto-negotiation: on > Supports Wake-on: g > Wake-on: d > Link detected: yes > > [root@localhost mcp65]# netperf -v -t TCP_STREAM -H 172.16.1.7 > TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 172.16.1.7 (172.16.1.7) port 0 AF_INET > 132.64 Hmm, I'm surprised that the lack of a value following the -v was successful - I'll have to go back and look at the code :) Still, I guess it gave you the desired "-v 0" behaviour. > [root@localhost mcp65]# netstat -Ieth0 > Kernel Interface table > Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVRFlg > eth0 1500 0 84682 2933 0 0 127298 0 0 0BMRU > > > I hope this is what you asked for ... Close enough. I suspect that if you were to snap netstat -s -t before and after the netperf you'd have seen retransmissions correlated to those "RX-ERR" stats. My history is such that I don't think of netstat for link-level stats and only think of it in the context of IP-layer and higher (eg tcp). Clearly something is fubar with the rx side (well duh :). The next set of stats I'd try to look at would be ethtool stats for the interface, eg ethtool -S eth0 and see if it shows someting more specific for the "RX-ERR" shown by netstat -I eth0. rick jones