Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751744AbaBHNuJ (ORCPT ); Sat, 8 Feb 2014 08:50:09 -0500 Received: from mail-pa0-f50.google.com ([209.85.220.50]:36861 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751296AbaBHNuH (ORCPT ); Sat, 8 Feb 2014 08:50:07 -0500 Message-ID: <1391867404.10160.88.camel@edumazet-glaptop2.roam.corp.google.com> 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] From: Eric Dumazet To: Thomas Glanzmann Cc: John Ogness , Eric Dumazet , "David S. Miller" , "Nicholas A. Bellinger" , target-devel , Linux Network Development , LKML Date: Sat, 08 Feb 2014 05:50:04 -0800 In-Reply-To: <1391866389.10160.80.camel@edumazet-glaptop2.roam.corp.google.com> 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> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 2014-02-08 at 05:33 -0800, Eric Dumazet wrote: > On Sat, 2014-02-08 at 05:14 -0800, Eric Dumazet wrote: > > Here is the combined patch, could you test it ? > > Also make sure you have commit a181ceb501b31b4bf8812a5c84c716cc31d82c2d > ("tcp: autocork should not hold first packet in write queue") > in your tree. > > BTW this problem demonstrates there is room for improvement in iCSCI, using MSG_MORE to avoid sending two small segments in separate frames. [1] 00:32:35.726568 IP 10.101.99.5.3260 > 10.101.0.13.27778: Flags [P.], seq 145:193, ack 144, win 235, options [nop,nop,TS val 4294960733 ecr 385385], length 48 [2] 00:32:35.838074 IP 10.101.0.13.27778 > 10.101.99.5.3260: Flags [.], ack 193, win 514, options [nop,nop,TS val 385396 ecr 4294960733], length 0 [3] 00:32:35.838099 IP 10.101.99.5.3260 > 10.101.0.13.27778: Flags [P.], seq 193:705, ack 144, win 235, options [nop,nop,TS val 4294960761 ecr 385396], length 512 [1] & [3] could be coalesced, and [2] would be avoided. -- 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/