From owner-cvs-src@FreeBSD.ORG Mon Mar 1 06:57:23 2004 Return-Path: Delivered-To: cvs-src@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 9D95116A4CE for ; Mon, 1 Mar 2004 06:57:23 -0800 (PST) Received: from tx1.oucs.ox.ac.uk (tx1.oucs.ox.ac.uk [129.67.1.167]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3C15C43D41 for ; Mon, 1 Mar 2004 06:57:23 -0800 (PST) (envelope-from colin.percival@wadham.ox.ac.uk) Received: from scan1.oucs.ox.ac.uk ([129.67.1.166] helo=localhost) by tx1.oucs.ox.ac.uk with esmtp (Exim 4.24) id 1AxorC-0000wm-HY for cvs-src@FreeBSD.org; Mon, 01 Mar 2004 14:57:22 +0000 Received: from rx1.oucs.ox.ac.uk ([129.67.1.165]) by localhost (scan1.oucs.ox.ac.uk [129.67.1.166]) (amavisd-new, port 25) with ESMTP id 03232-10 for ; Mon, 1 Mar 2004 14:57:22 +0000 (GMT) Received: from gateway.wadham.ox.ac.uk ([163.1.161.253]) by rx1.oucs.ox.ac.uk with smtp (Exim 4.24) id 1AxorC-0000wY-3e for cvs-src@FreeBSD.org; Mon, 01 Mar 2004 14:57:22 +0000 Received: (qmail 523 invoked by uid 0); 1 Mar 2004 14:57:18 -0000 Received: from colin.percival@wadham.ox.ac.uk by gateway by uid 71 with qmail-scanner-1.16 (sweep: 2.14/3.71. spamassassin: 2.53. Clear:. Processed in 2.966787 secs); 01 Mar 2004 14:57:18 -0000 X-Qmail-Scanner-Mail-From: colin.percival@wadham.ox.ac.uk via gateway X-Qmail-Scanner: 1.16 (Clear:. Processed in 2.966787 secs) Received: from dhcp1131.wadham.ox.ac.uk (HELO piii600.wadham.ox.ac.uk) (163.1.161.131) by gateway.wadham.ox.ac.uk with SMTP; 1 Mar 2004 14:57:15 -0000 Message-Id: <6.0.1.1.1.20040301145406.038ede88@imap.sfu.ca> X-Sender: cperciva@imap.sfu.ca (Unverified) X-Mailer: QUALCOMM Windows Eudora Version 6.0.1.1 Date: Mon, 01 Mar 2004 14:57:09 +0000 To: Bruce Evans From: Colin Percival In-Reply-To: <20040301205527.H13424@gamplex.bde.org> References: <200402291558.i1TFwsGw035149@repoman.freebsd.org> <20040301205527.H13424@gamplex.bde.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed cc: cvs-src@FreeBSD.org cc: src-committers@FreeBSD.org cc: cvs-all@FreeBSD.org cc: Colin Percival Subject: Re: cvs commit: src/sys/dev/md md.c X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 01 Mar 2004 14:57:23 -0000 At 10:02 01/03/2004, Bruce Evans wrote: >On Sun, 29 Feb 2004, Colin Percival wrote: > > Modified files: > > sys/dev/md md.c > > Log: > > Use DEV_BSIZE byte sectors instead of PAGE_SIZE byte sectors for > > swap-backed memory disks. This reduces filesystem allocation overhead > > and makes swap-backed memory disks compatible with broken code (dd, > > for example) which expects to see 512 byte sectors. > >This was mostly a feature. It helped expose broken code that wants 512 >byte sectors. Well... yes, but I don't think it was an intended feature. :) > dd is as far as possible from being an example of such >code. It uses the requested block size which just defaults to 512. Ideally, dd should look at what it's being asked to access, and get a default block size from that. (Yes, there are much worse offenders, dd just happened to be the first problem which came to mind.) Colin Percival