From: Eric Dumazet <eric.dumazet@gmail.com>
To: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
Cc: Linux Netdev List <netdev@vger.kernel.org>
Subject: Re: 10GBE performance drop with net.ipv4.tcp_timestamps=0
Date: Wed, 20 Jun 2012 09:22:20 +0200 [thread overview]
Message-ID: <1340176940.4604.801.camel@edumazet-glaptop> (raw)
In-Reply-To: <4FE17522.5050005@profihost.ag>
On Wed, 2012-06-20 at 09:00 +0200, Stefan Priebe - Profihost AG wrote:
> Am 19.06.2012 23:31, schrieb Eric Dumazet:
> > On Tue, 2012-06-19 at 23:08 +0200, Stefan Priebe wrote:
> >> i'm testing 10GBE speed with tweo servers. One with 3.5-rc3 nd thoe
> >> other one whith RHEL 6 (2.6.32 kernel).
> >>
> >> I noticed that setting
> >> net.ipv4.tcp_timestamps=0
> >>
> >> descreased the performance from 9,7 Full Duplex to 3-4Gb/s.
> >>
> >> Is this bahviour fine? What should / could i tet?
> >>
> >
> > Really, you should provide more input than that, if you really want us
> > to help.
>
> *arg* forgot to add the pastebin links. Sorry. Speed degraded in this
> case from 9,88Gbit/s to 2,45Gbit/s. When i turn on timestamps it's
> perfect again. Server A has 3.5.0-rc3 and server B has an RHEL6 2.6.32
> kernel.
>
> Before:
> http://pastebin.com/raw.php?i=1gVraWVc
>
> After:
> http://pastebin.com/raw.php?i=NSh8Y29s
You have a lot of packet losses
add "tc -s -d qdisc" , "ifconfig -a " and "ethtool -S ethX" outputs for
both servers
next prev parent reply other threads:[~2012-06-20 7:22 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-19 21:08 10GBE performance drop with net.ipv4.tcp_timestamps=0 Stefan Priebe
2012-06-19 21:31 ` Eric Dumazet
2012-06-20 7:00 ` Stefan Priebe - Profihost AG
2012-06-20 7:22 ` Eric Dumazet [this message]
2012-06-20 8:21 ` Stefan Priebe - Profihost AG
2012-06-20 8:41 ` Eric Dumazet
2012-06-20 9:06 ` Stefan Priebe - Profihost AG
2012-06-20 9:12 ` Stefan Priebe - Profihost AG
2012-06-20 9:17 ` Eric Dumazet
2012-06-20 9:25 ` Stefan Priebe - Profihost AG
2012-06-20 9:28 ` Eric Dumazet
2012-06-20 9:33 ` Stefan Priebe - Profihost AG
2012-06-20 9:47 ` Eric Dumazet
2012-06-20 9:50 ` Stefan Priebe - Profihost AG
2012-06-20 10:06 ` Eric Dumazet
2012-06-20 11:08 ` Eric Dumazet
2012-06-20 9:16 ` Eric Dumazet
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