From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761033AbXGPOGa (ORCPT ); Mon, 16 Jul 2007 10:06:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932372AbXGPOFW (ORCPT ); Mon, 16 Jul 2007 10:05:22 -0400 Received: from Mycroft.westnet.com ([216.187.52.7]:62496 "EHLO Mycroft.westnet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932503AbXGPOFT (ORCPT ); Mon, 16 Jul 2007 10:05:19 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <18075.31515.974905.507754@stoffel.org> Date: Mon, 16 Jul 2007 10:05:15 -0400 From: "John Stoffel" To: Jens Axboe Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org Subject: Re: [PATCH 00/33] SG table chaining support In-Reply-To: <11845792671245-git-send-email-jens.axboe@oracle.com> References: <11845792671245-git-send-email-jens.axboe@oracle.com> X-Mailer: VM 7.19 under Emacs 21.4.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jens> A repost of this patchset, which adds support forchaining of sg Jens> tables. This enables much larger IO commands, since we don't Jens> have to allocate large consecutive pieces of memory to represent Jens> the sgtable of a huge command. Right now Linux is limited to Jens> somewhere between 128 and 256 segments, depending on the Jens> architecture. This translates into at most 512k-1mb request Jens> sizes. With this patchset, I've successfully pushed 10MiB Jens> commands through the IO stack. Will this help out tape drive performance at all? I looked through the patches quickly, esp the AIC7xxx stuff since that's what I use, but nothing jumped out at me... John