Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965201AbVJVC3f (ORCPT ); Fri, 21 Oct 2005 22:29:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932569AbVJVC3f (ORCPT ); Fri, 21 Oct 2005 22:29:35 -0400 Received: from zorg.st.net.au ([203.16.233.9]:53434 "EHLO borg.st.net.au") by vger.kernel.org with ESMTP id S932119AbVJVC3e (ORCPT ); Fri, 21 Oct 2005 22:29:34 -0400 Message-ID: <4359A44B.3090804@torque.net> Date: Sat, 22 Oct 2005 12:30:35 +1000 From: Douglas Gilbert Reply-To: dougg@torque.net User-Agent: Mozilla Thunderbird 1.0.6-1.1.fc4 (X11/20050720) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Matthew Wilcox CC: Luben Tuikov , Christoph Hellwig , Jeff Garzik , andrew.patterson@hp.com, "Moore, Eric Dean" , jejb@steeleye.com, linux-scsi@vger.kernel.org, Linux Kernel , Linus Torvalds Subject: Re: ioctls, etc. (was Re: [PATCH 1/4] sas: add flag for locally attached PHYs) References: <91888D455306F94EBD4D168954A9457C048F0E34@nacos172.co.lsil.com> <20051020160155.GA14296@lst.de> <4357CB03.4020400@adaptec.com> <20051020170330.GA16458@lst.de> <4357F7DE.7050004@adaptec.com> <1129852879.30258.137.camel@bluto.andrew> <43583A53.2090904@pobox.com> <435929FD.4070304@adaptec.com> <20051021180455.GA6834@lst.de> <43592FA1.8000206@adaptec.com> <20051021182009.GA3364@parisc-linux.org> In-Reply-To: <20051021182009.GA3364@parisc-linux.org> X-Enigmail-Version: 0.92.0.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1298 Lines: 35 Matthew Wilcox wrote: > On Fri, Oct 21, 2005 at 02:12:49PM -0400, Luben Tuikov wrote: > >>>That beeing said I tried this approach. It looks pretty cool when you >>>think about it, but the block layer is quite a bit too heavyweight for >>>queueing up a few SMP requests, and we need to carry too much useless >>>code around for it. >> >>That's the last reason not to implement SMP as a block device. >>But this is good that you tried it and it "flopped". This way >>people will stop repeating "SMP... block device". > > > Block layer != Block device. > > Nobody wants to implement SMP as a block device. > > The question is whether the SMP interface should be implemented as part > of the block layer. However, the block layer is used in the context of a block device (and in some cases a char device). If SAS domain discovery is done from the user space, and the root file system is the far side of a SAS expander, there are no suitable devices, just the SAS initiator (HBA) which currently we cannot address via the block layer. Doug Gilbert - 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/