From owner-cvs-all Sun Sep 19 1:12:16 1999 Delivered-To: cvs-all@freebsd.org Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.40.131]) by hub.freebsd.org (Postfix) with ESMTP id 4137614CFA; Sun, 19 Sep 1999 01:12:11 -0700 (PDT) (envelope-from phk@critter.freebsd.dk) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.9.3/8.9.2) with ESMTP id KAA15066; Sun, 19 Sep 1999 10:10:51 +0200 (CEST) (envelope-from phk@critter.freebsd.dk) To: dg@root.com Cc: Greg Lehey , Matt Dillon , cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: User block device access (was: cvs commit: src/sys/miscfs/specfs spec_vnops.c src/sys/sys vnode.h src/sys/kern vfs_subr.c) In-reply-to: Your message of "Sun, 19 Sep 1999 00:48:41 PDT." <199909190748.AAA20860@implode.root.com> Date: Sun, 19 Sep 1999 10:10:50 +0200 Message-ID: <15064.937728650@critter.freebsd.dk> From: Poul-Henning Kamp Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk In message <199909190748.AAA20860@implode.root.com>, David Greenman writes: > The general feeling of both myself and Kirk McKusick is that the blocking/ >buffering should be done at the application level and not by the kernel and >that the block/buffered device should go away. My position is a little bit more flexible: I don't care which of the two interfaces we retain, as long as we only have one and as long as it isn't buggy (ie: it should return write errors). The argument for the block device is that it *is* more "unix feel" to be able to read and write at any byte and with any length. IFF we want to maintain the block interface, we need to fix the error return for the write case, but we also need to do a significant amount of work speeding it up. It currently is an order of magnitude slower than the char interface (remember to measure consumed CPU time, not wall-clock time). For anyone with a second disk or floppy drive in their system, attempting to fix the block dev interface is not a very hard problem. -- Poul-Henning Kamp FreeBSD coreteam member phk@FreeBSD.ORG "Real hackers run -current on their laptop." FreeBSD -- It will take a long time before progress goes too far! To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message