Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759411AbYA3Lkc (ORCPT ); Wed, 30 Jan 2008 06:40:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753507AbYA3LkU (ORCPT ); Wed, 30 Jan 2008 06:40:20 -0500 Received: from mail-relay-02.mailcluster.net ([77.221.130.214]:42127 "EHLO mail-relay-02.mailcluster.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752837AbYA3LkT (ORCPT ); Wed, 30 Jan 2008 06:40:19 -0500 Message-ID: <47A06218.7020006@vlnb.net> Date: Wed, 30 Jan 2008 14:40:08 +0300 From: Vladislav Bolkhovitin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.13) Gecko/20060501 Fedora/1.7.13-1.1.fc5 X-Accept-Language: en-us, ru, en MIME-Version: 1.0 To: FUJITA Tomonori CC: bart.vanassche@gmail.com, fujita.tomonori@lab.ntt.co.jp, rdreier@cisco.com, James.Bottomley@hansenpartnership.com, torvalds@linux-foundation.org, akpm@linux-foundation.org, linux-scsi@vger.kernel.org, scst-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: Integration of SCST in the mainstream Linux kernel References: <20080130083239E.fujita.tomonori@lab.ntt.co.jp> <20080130195635T.tomof@acm.org> In-Reply-To: <20080130195635T.tomof@acm.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2319 Lines: 57 FUJITA Tomonori wrote: > On Wed, 30 Jan 2008 09:38:04 +0100 > "Bart Van Assche" wrote: > > >>On Jan 30, 2008 12:32 AM, FUJITA Tomonori wrote: >> >>>iSER has parameters to limit the maximum size of RDMA (it needs to >>>repeat RDMA with a poor configuration)? >> >>Please specify which parameters you are referring to. As you know I > > > Sorry, I can't say. I don't know much about iSER. But seems that Pete > and Robin can get the better I/O performance - line speed ratio with > STGT. > > The version of OpenIB might matters too. For example, Pete said that > STGT reads loses about 100 MB/s for some transfer sizes for some > transfer sizes due to the OpenIB version difference or other unclear > reasons. > > http://article.gmane.org/gmane.linux.iscsi.tgt.devel/135 > > It's fair to say that it takes long time and need lots of knowledge to > get the maximum performance of SAN, I think. > > I think that it would be easier to convince James with the detailed > analysis (e.g. where does it take so long, like Pete did), not just > 'dd' performance results. > > Pushing iSCSI target code into mainline failed four times: IET, SCST, > STGT (doing I/Os in kernel in the past), and PyX's one (*1). iSCSI > target code is huge. You said SCST comprises 14,000 lines, but it's > not iSCSI target code. The SCSI engine code comprises 14,000 > lines. You need another 10,000 lines for the iSCSI driver. Note that > SCST's iSCSI driver provides only basic iSCSI features. PyX's iSCSI > target code implemenents more iSCSI features (like MC/S, ERL2, etc) > and comprises about 60,000 lines and it still lacks some features like > iSER, bidi, etc. > > I think that it's reasonable to say that we need more than 'dd' > results before pushing about possible more than 60,000 lines to > mainline. Tomo, please stop counting in-kernel lines only (see http://lkml.org/lkml/2007/4/24/364). The amount of the overall project lines for the same feature set is a lot more important. > (*1) http://linux-iscsi.org/ > -- 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/