From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Priebe - Profihost AG Subject: Re: 10GBE performance drop with net.ipv4.tcp_timestamps=0 Date: Wed, 20 Jun 2012 11:33:50 +0200 Message-ID: <4FE198FE.5050202@profihost.ag> References: <4FE0EA33.1000309@profihost.ag> <1340141493.4604.773.camel@edumazet-glaptop> <4FE17522.5050005@profihost.ag> <1340176940.4604.801.camel@edumazet-glaptop> <4FE1881B.7030800@profihost.ag> <1340181676.4604.838.camel@edumazet-glaptop> <4FE192A1.6000000@profihost.ag> <4FE193FA.5030802@profihost.ag> <1340183854.4604.847.camel@edumazet-glaptop> <4FE196F4.3040900@profihost.ag> <1340184528.4604.849.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Linux Netdev List To: Eric Dumazet Return-path: Received: from mail.profihost.ag ([85.158.179.208]:50926 "EHLO mail.profihost.ag" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754709Ab2FTJd4 (ORCPT ); Wed, 20 Jun 2012 05:33:56 -0400 In-Reply-To: <1340184528.4604.849.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: Am 20.06.2012 11:28, schrieb Eric Dumazet: > On Wed, 2012-06-20 at 11:25 +0200, Stefan Priebe - Profihost AG wrote: >> Am 20.06.2012 11:17, schrieb Eric Dumazet: >>> On Wed, 2012-06-20 at 11:12 +0200, Stefan Priebe - Profihost AG wrote: >>>> 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. >> >>> If you exchange sender/receiver role between linux kernel versions, is >>> it the same problem ? >> I'm testing in both directions. So both are sending and receiving. >> >> I've now made tests with only one sending an the other receiving. >> >> When server B is the sender i get 4Gbit/s. When server A is the sender i >> get full 9,9Gbit/s. >> > To rule out bad hardware, could you try a 3.5-rc3 kernel on B ? Sure. In that case i get 4Gbit/s in both variants. I also tried two other different machines same result. Stefan