From owner-freebsd-current Mon Sep 22 13:05:23 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id NAA14902 for current-outgoing; Mon, 22 Sep 1997 13:05:23 -0700 (PDT) Received: from usr06.primenet.com (tlambert@usr06.primenet.com [206.165.6.206]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id NAA14890 for ; Mon, 22 Sep 1997 13:05:18 -0700 (PDT) Received: (from tlambert@localhost) by usr06.primenet.com (8.8.5/8.8.5) id NAA19844; Mon, 22 Sep 1997 13:05:04 -0700 (MST) From: Terry Lambert Message-Id: <199709222005.NAA19844@usr06.primenet.com> Subject: Re: cvs commit: src/sys/conf files src/sys/dev/vx if_vx.c if_vxreg.h src/sys/i386/apm apm.c src/sys/i386/conf GENERIC files.i386 To: nate@mt.sri.com (Nate Williams) Date: Mon, 22 Sep 1997 20:05:04 +0000 (GMT) Cc: julian@whistle.com, gibbs@plutotech.com, bde@zeta.org.au, nate@mt.sri.com, current@FreeBSD.ORG In-Reply-To: <199709221745.LAA01369@rocky.mt.sri.com> from "Nate Williams" at Sep 22, 97 11:45:24 am X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-freebsd-current@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > In theory, I disagree. We can't 'move forward' w/out breaking device > compatability with other systems, and if the changes allow to > effeciently do things in the manner described in the paper, it's a step > in the right direction. For example, making the VM system 'useful' > required changing a standard kernel interface (although it was neither > well documented nor well understood.) For another, making the VFS useful required changes as well. Wait... those changes were never committed. 8-) 8-). > But, I want to know that it is indeed an improvement, and not merely a > change that is needed to support Justin's CAM work, and something that > could have been done in a manner that took the good ideas from the work > but implemented them in a manner that was less intrusive. This is still a good point. I want to see the timer code move toward RT support, meaning timer based involuntary preemption of non-RT processes for timers belonging to RT processes, and for removal of all buzz-loops in the kernel, and movement of the FT driver guarantees to the kernel istead of an FT device. To my mind, the new code moves at an oblique angle, and takes the kernel further away from these goals. While I admit that probably not everyone shares these goals, it is still possible to argue against making them architecturally harder to achieve, even if they aren't your goals. Any design which limits future work is broken (the statement of this principle shows the relevance of the VFS reference above). > > all my drivers that are shared between various OS now need to > > be modified, with a new #if defined(__FreeBSD__) in them. > > Actually, if Justin's work was the same as the original code, you should > still be able to use the old 'timeout' functionality, it just doens't > take advantage of some of the newer features. I think this was targetted at the bitmaps; I could be wrong. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.