From owner-freebsd-smp Wed Jul 16 03:34:40 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id DAA04027 for smp-outgoing; Wed, 16 Jul 1997 03:34:40 -0700 (PDT) Received: from bagpuss.visint.co.uk (bagpuss.visint.co.uk [194.207.134.1]) by hub.freebsd.org (8.8.5/8.8.5) with ESMTP id DAA04019 for ; Wed, 16 Jul 1997 03:34:31 -0700 (PDT) Received: from dylan.visint.co.uk (dylan.visint.co.uk [194.207.134.180]) by bagpuss.visint.co.uk (8.7.5/8.7.3) with SMTP id LAA00332; Wed, 16 Jul 1997 11:34:23 +0100 (BST) Date: Wed, 16 Jul 1997 11:34:23 +0100 (BST) From: Stephen Roome To: Steve Passe cc: smp@FreeBSD.ORG Subject: Re: HEADS UP: EISA cards. In-Reply-To: <199707160551.XAA06975@Ilsa.StevesCafe.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-smp@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk On Tue, 15 Jul 1997, Steve Passe wrote: > I am about to make a design decision that will forever-more make the use > of EISA cards that use the EISA chipset DMA circuit impossible in the SMP > kernel. I posted a rather long email about this several days ago but got ZERO > response. So I can conclude that either: > > a: everyone agrees with this decision. > OR > b: no one with such hardware read that far. (Warning: uninformed gut-reactions follow) I think you missed out c: which was that some folks, me included, didn't entirely follow the implications, but IMHO, I wouldn't build an SMP system relying heavily or even using EISA. It sounds to me like a small loss, but as I'm not sure exactly how much is gained out of it I couldn't make the decision either. Basically: 1) I don't use EISA cards except in one 486 here, and that's going asap as well. 2) In an SMP system I would always use PCI instead of EISA, only because if I'm buying an SMP system it's due to performance/newness issues and EISA wouldn't be my choice of performance/newest peripherals. > we need to make a policy decision as to whether we can say > bye-bye to the DMA chaining INTs. If I don't get thoughtful feedback on this > I will just nmake an arbitrary decision (which I suspect to be axing the DMA > INTs). I think the only situation needing them is non-busmaster EISA hardware > that does DMA via the motherboard chipset DMA registers. Please correct me > if I am wrong on this point. Well, if you're right these don't sound like the sort of cards I'd be buying for a smp machine. -- Steve Roome - Vision Interactive Ltd. Tel:+44(0)117 9730597 Home:+44(0)976 241342 WWW: http://dylan.visint.co.uk/