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From: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Linux Netdev List <netdev@vger.kernel.org>
Subject: Re: 10GBE performance drop with net.ipv4.tcp_timestamps=0
Date: Wed, 20 Jun 2012 11:12:26 +0200	[thread overview]
Message-ID: <4FE193FA.5030802@profihost.ag> (raw)
In-Reply-To: <4FE192A1.6000000@profihost.ag>

Am 20.06.2012 11:06, schrieb Stefan Priebe - Profihost AG:
>> You seem to have a switch or something that drops packets in this case.
>> You could try to rate limit to 9Gb/s and see if it is better.
> Sadly i can't rate limit to 9Gbit/s on the switch.
>
>> Here, I roughly have same bandwidth with tcp_timestamps on or off, with
>> ixgbe cards and net-next kernels.
> Mhm strange. Do you have any vague idea what could cause this? Any wrong
> reordering of the packets without tcp_timestamps?

I've now done another test without the switch. So both systems where 
direct attached and still the same. Without tcp_timstamps speed drops to 
2-4Gbit/s.

Stefan

  reply	other threads:[~2012-06-20  9:12 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
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 [this message]
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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