Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755157AbZDNL7j (ORCPT ); Tue, 14 Apr 2009 07:59:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755029AbZDNL7X (ORCPT ); Tue, 14 Apr 2009 07:59:23 -0400 Received: from tamago.serverit.net ([91.189.209.155]:57395 "EHLO mail.hosting2.serverit.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755330AbZDNL7V (ORCPT ); Tue, 14 Apr 2009 07:59:21 -0400 Date: Tue, 14 Apr 2009 14:58:11 +0300 (EEST) From: Szabolcs Szakacsits X-X-Sender: szaka@tamago.serverit.net To: Jeff Garzik cc: Avi Kivity , Linus Torvalds , Alan Cox , Grant Grundler , Linux IDE mailing list , LKML , Jens Axboe , Arjan van de Ven Subject: Re: Implementing NVMHCI... In-Reply-To: <49E47744.3040103@garzik.org> Message-ID: References: <20090412091228.GA29937@elte.hu> <20090412162018.6c1507b4@lxorguk.ukuu.org.uk> <49E213AE.4060506@redhat.com> <49E2DC96.6090407@redhat.com> <49E45E9C.1020105@redhat.com> <49E46437.5000804@garzik.org> <49E46779.1040106@redhat.com> <49E47744.3040103@garzik.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1201 Lines: 33 On Tue, 14 Apr 2009, Jeff Garzik wrote: > Avi Kivity wrote: > > Jeff Garzik wrote: > > > Speaking of RMW... in one sense, we have to deal with RMW anyway. > > > Upcoming ATA hard drives will be configured with a normal 512b sector API > > > interface, but underlying physical sector size is 1k or 4k. > > > > > > The disk performs the RMW for us, but we must be aware of physical sector > > > size in order to determine proper alignment of on-disk data, to minimize > > > RMW cycles. > > > > > > > Virtualization has the same issue. OS installers will typically setup the > > first partition at sector 63, and that means every page-sized block access > > will be misaligned. Particularly bad when the guest's disk is backed on a > > regular file. > > > > Windows 2008 aligns partitions on a 1MB boundary, IIRC. > > Makes a lot of sense... Since Vista at least the first partition is 2048 sector aligned. Szaka -- NTFS-3G: http://ntfs-3g.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/