Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751823AbaBHNiw (ORCPT ); Sat, 8 Feb 2014 08:38:52 -0500 Received: from infra.glanzmann.de ([88.198.249.254]:60741 "EHLO infra.glanzmann.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751760AbaBHNiu (ORCPT ); Sat, 8 Feb 2014 08:38:50 -0500 Date: Sat, 8 Feb 2014 14:38:47 +0100 From: Thomas Glanzmann To: Eric Dumazet Cc: John Ogness , Eric Dumazet , "David S. Miller" , "Nicholas A. Bellinger" , target-devel , Linux Network Development , LKML Subject: Re: REGRESSION f54b311142a92ea2e42598e347b84e1655caf8e3 tcp auto corking slows down iSCSI file system creation by factor of 70 [WAS: 4 TB VMFS creation takes 15 minutes vs 26 seconds] Message-ID: <20140208133847.GB20512@glanzmann.de> Mail-Followup-To: Eric Dumazet , John Ogness , Eric Dumazet , "David S. Miller" , "Nicholas A. Bellinger" , target-devel , Linux Network Development , LKML References: <20140206153640.GB4103@glanzmann.de> <1391727771.14985.41.camel@haakon3.risingtidesystems.com> <20140207051500.GB10916@glanzmann.de> <20140207075536.GB17815@glanzmann.de> <1391801597.1155.28.camel@haakon3.risingtidesystems.com> <20140207205142.GA8609@glanzmann.de> <20140208093808.GD16336@glanzmann.de> <1391865273.10160.76.camel@edumazet-glaptop2.roam.corp.google.com> <1391866389.10160.80.camel@edumazet-glaptop2.roam.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1391866389.10160.80.camel@edumazet-glaptop2.roam.corp.google.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Eric, > Also make sure you have commit a181ceb501b31b4bf8812a5c84c716cc31d82c2d > ("tcp: autocork should not hold first packet in write queue") > in your tree. confirmed: (node-62) [~/work/linux-2.6] git show a181ceb501b31b4bf8812a5c84c716cc31d82c2d | head commit a181ceb501b31b4bf8812a5c84c716cc31d82c2d Author: Eric Dumazet Date: Tue Dec 17 09:58:30 2013 -0800 tcp: autocork should not hold first packet in write queue Willem noticed a TCP_RR regression caused by TCP autocorking on a Mellanox test bed. MLX4_EN_TX_COAL_TIME is 16 us, which can be right above RTT between hosts. Cheers, Thomas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/