Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757518AbZAMBHb (ORCPT ); Mon, 12 Jan 2009 20:07:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757278AbZAMBG6 (ORCPT ); Mon, 12 Jan 2009 20:06:58 -0500 Received: from ftp.linux-mips.org ([213.58.128.207]:41915 "EHLO ftp.linux-mips.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757236AbZAMBG5 (ORCPT ); Mon, 12 Jan 2009 20:06:57 -0500 Date: Tue, 13 Jan 2009 01:06:55 +0000 (GMT) From: "Maciej W. Rozycki" To: Ingo Molnar cc: Alan Cox , Peter Zijlstra , Jiri Kosina , Adam Osuchowski , linux-kernel@vger.kernel.org, Nick Piggin , Thomas Gleixner , "H. Peter Anvin" Subject: Re: Is 386 processor still supported? In-Reply-To: <20090108151046.GK18120@elte.hu> Message-ID: References: <20090108120338.6b8b4567@zonk.pl> <1231424025.11687.447.camel@twins> <1231424833.11687.452.camel@twins> <20090108150448.2393aeb0@lxorguk.ukuu.org.uk> <20090108151046.GK18120@elte.hu> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1195 Lines: 26 On Thu, 8 Jan 2009, Ingo Molnar wrote: > > So our minimal spec for SMP is probably 486DX + external Intel APIC. > > > > In practice I doubt there is a single Intel APIC type 486 SMP box on the > > planet running Linux (or quite possibly running at all) > > yeah, that's very likely true. I think we could eliminate some of the SMP > complications by requiring cmpxchg presence for CONFIG_SMP, agreed? I failed to track down a single 486 SMP system that would adhere to the MP spec. There were and possibly still are APIC-based 486 SMP systems out there, but most likely they are not Intel MPS-compliant, by not providing the MP header at the very least. Thus Linux would have to be ported and I gather the interest in doing so is epsilon. Myself, I could not resist trying an APIC-based 486 SMP box and possibly fixing issues if I found one and it was MPS-compliant, but nothing beyond that I would say. Life's too short. Maciej -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/