netdev - Re: unstable 10GBE performance with recent kernels (> 3.0.X)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1340012706.7491.770.camel@edumazet-glaptop>
Date:	Mon, 18 Jun 2012 11:45:06 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Stefan Priebe - Profihost AG <s.priebe@...fihost.ag>
Cc:	Linux Netdev List <netdev@...r.kernel.org>
Subject: Re: unstable 10GBE performance with recent kernels (> 3.0.X)

On Mon, 2012-06-18 at 11:22 +0200, Stefan Priebe - Profihost AG wrote:
> Hello list,
> 
> i've discovered very unstable 10GBE performance using recent kernels. 
> I'm using some optimized settings mentioned by intel here 
> (part:Improving Performance): 
> http://downloadmirror.intel.com/5874/eng/README.txt
> 

like what settings ?

> I'm using Intel X520 cards (ixgbe driver version: 3.9.17-NAPI in all 
> tests).
> 
> I'm measuring the performance with iperf.
> 
> With 3.0.32 i get constant 9,90 Gbit/s in both directions simultaneously.
> 
> With 3.4.2 or 3.5.0-rc2 it get sometimes 9,9gbit/s - sometimes 3gbit/s 
> or even sometimes only 1gbit/s throughput.
> 
> I also tried to change the tcp_congestion_control from cubic to reno, 
> bic and highspeed but no change.
> 
> I also tried to bisect the issue but there are so many changes in the 
> net kernel part that i'm unable to identify the problem as with some 
> commits i only get 0-300kb/s performance.
> 
> Any ideas?

ethtool -S eth0
ethtool -k eth0
netstat -s   (on sender, on receiver)

single flow , multiple flows ?


--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html