From owner-freebsd-arch Wed May 24 9:52:15 2000 Delivered-To: freebsd-arch@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [216.240.41.2]) by hub.freebsd.org (Postfix) with ESMTP id E77B137BCF8 for ; Wed, 24 May 2000 09:52:12 -0700 (PDT) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.3/8.9.1) id JAA75843; Wed, 24 May 2000 09:52:04 -0700 (PDT) (envelope-from dillon) Date: Wed, 24 May 2000 09:52:04 -0700 (PDT) From: Matthew Dillon Message-Id: <200005241652.JAA75843@apollo.backplane.com> To: "Daniel C. Sobral" Cc: Chuck Paterson , arch@FreeBSD.ORG Subject: Re: Preemptive kernel on older X86 hardware References: <200005241446.IAA05589@berserker.bsdi.com> <392BF518.F8170D0E@newsguy.com> Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :> processors might not be required. I'll propose the following as it :> reduces the work required: :> :> Once FreeBSD has a preemptive kernel FreeBSD will only run on :> Pentium or better X86 processors. : :We had a lot of trouble already making people give up on their MFM/RLL :controllers! : :Personally, I think this is the way to go, but not before 6.0. If 5.0 :doesn't work on 486's, there'll be hell to pay. : :-- :Daniel C. Sobral (8-DCS) Woa everyone, before this blows up into an unnecessary flamefest... Nobody is advocating scrapping the 386 for UP kernels. Even when/if the kernel becomes threaded, it still probably will not be preemptive but even if it were we are not going to be throwing cmpexg instructions in mainline *UP* code. If some of the imported code happens to do that, it's trivial to fix with #ifdef's for 386/486 support. For SMP kernels I don't think it's worth supporting either the 386 or the 486. -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message