Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763940AbXLUAbS (ORCPT ); Thu, 20 Dec 2007 19:31:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755274AbXLUAbA (ORCPT ); Thu, 20 Dec 2007 19:31:00 -0500 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:42611 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755232AbXLUAa7 (ORCPT ); Thu, 20 Dec 2007 19:30:59 -0500 Date: Thu, 20 Dec 2007 16:30:58 -0800 (PST) Message-Id: <20071220.163058.185565456.davem@davemloft.net> To: rusty@rustcorp.com.au Cc: fujita.tomonori@lab.ntt.co.jp, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, jens.axboe@oracle.com, dougg@torque.net Subject: Re: [PATCH 0/5] sg_ring for scsi From: David Miller In-Reply-To: <200712211013.38511.rusty@rustcorp.com.au> References: <200712201853.48643.rusty@rustcorp.com.au> <20071219.235807.173273479.davem@davemloft.net> <200712211013.38511.rusty@rustcorp.com.au> X-Mailer: Mew version 5.2 on Emacs 22.1 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 907 Lines: 20 From: Rusty Russell Date: Fri, 21 Dec 2007 10:13:38 +1100 > But, as demonstrated, there are real benefits of having an explicit header: > > 1) It removes the chain-end/explicit count ambiguity (see > http://lkml.org/lkml/2007/10/25/209 & thread) > 2) It allows others to manipulate sg chains, which couldn't be done before > (eg. the ATA code which wants to append a padding element). > 3) I can now hand you an sg ring for you to fill: sg chains can't do that. > > In short, sg_ring is generally useful primitive. sg chains are a clever hack > for scsi_lib to create, and everyone else to read. I do not refute any of this :-) -- 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/