From owner-freebsd-current Mon Mar 11 13:27:51 1996 Return-Path: owner-current Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id NAA19254 for current-outgoing; Mon, 11 Mar 1996 13:27:51 -0800 (PST) Received: from GndRsh.aac.dev.com (GndRsh.aac.dev.com [198.145.92.241]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id NAA19220 for ; Mon, 11 Mar 1996 13:27:42 -0800 (PST) Received: (from rgrimes@localhost) by GndRsh.aac.dev.com (8.6.12/8.6.12) id NAA12878; Mon, 11 Mar 1996 13:25:42 -0800 From: "Rodney W. Grimes" Message-Id: <199603112125.NAA12878@GndRsh.aac.dev.com> Subject: Re: AMD doesn't like SNAP! (panic: unwire: page not in pmap) To: jgreco@brasil.moneng.mei.com (Joe Greco) Date: Mon, 11 Mar 1996 13:25:42 -0800 (PST) Cc: jehamby@lightside.com, current@FreeBSD.ORG, jkh@time.cdrom.com, toor@dyson.iquest.net In-Reply-To: <199603111630.KAA17767@brasil.moneng.mei.com> from "Joe Greco" at Mar 11, 96 10:30:39 am X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-current@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > > > > So far three people, including myself, have reported the above panic > > > message when booting the 3/3 SNAP kernel. All three of us have AMD DX4 > > > processors (100 and 120MHz). This has got to be the problem! John, > > > Jordan, people working on the VM system, take note.. Thanks! > > > > Can all three of you tell me if you have A80486DX4-100NV8T's or > > A80486DX4-100SV8B's? The difference is the SV8B is the write back > > enhanced DX4 and unless you have a motherboard that understands > > how to deal with this you are going to have a cache coherency problem > > between the internal and external cache. > > > > I have yet to see a MB deal with this correctly when faced with > > a bus master SCSI controller, though I have seen some that work fine > > as long as no bus mastering is occuring. Far more don't work than > > do work. > > > > If you don't have SV8B's or are not running them in WB mode, then > > I don't have any idea what has gone wrong... > > Ummmm. Ummmm.. that may explain a problem I have been seeing. :-) > > I have a pair of DX4/120's ("Enhanced"), one with IDE disk, one with 1542 > and SCSI disk. The one with SCSI disk is unhappy during big compiles (make > world, etc). I haven't _noticed_ problems with the IDE disk. Same MB/cpu, > etc. > > Rod, you seem to imply that by NOT running them in WB mode, the problem may > not manifest itself (dependent upon the MB). Is this what you meant to > imply? Yes, that is exactly what I meant to imply. > Can you recommend a good 486 motherboard (preferably PCI)? Nope, IMHO, there are no _good_ 486 boards left on the market, the last _good_ 486 PCI board I could get was the ASUS PCI/I-486SP3G and I have not been able to get any more of them. > Argh, I just got the fingers on my left hand wired to equipment in the next > office.. hard to type.. > > I noticed ASUS seems to have several other offerings besides the SP3G.. Such as what, the PVI-486AP4, out of production for 4 months, the only 486 board that I know ASUS is still makeing is the PVI-486SP3, which I do not classify as a good board due to only 2 Simm sockets and if I recall correctly a cache coherency problem in the Sis 496/497 chipset. -- Rod Grimes rgrimes@gndrsh.aac.dev.com Accurate Automation Company Reliable computers for FreeBSD