From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by oss.sgi.com id ; Mon, 13 Mar 2000 00:44:20 -0800 Received: from pneumatic-tube.sgi.com ([204.94.214.22]:20515 "EHLO pneumatic-tube.sgi.com") by oss.sgi.com with ESMTP id ; Mon, 13 Mar 2000 00:44:02 -0800 Received: from cthulhu.engr.sgi.com (cthulhu.engr.sgi.com [192.26.80.2]) by pneumatic-tube.sgi.com (980327.SGI.8.8.8-aspam/980310.SGI-aspam) via ESMTP id AAA05367; Mon, 13 Mar 2000 00:47:23 -0800 (PST) mail_from (owner-linux@cthulhu.engr.sgi.com) Received: (from majordomo-owner@localhost) by cthulhu.engr.sgi.com (980427.SGI.8.8.8/970903.SGI.AUTOCF) id AAA47871 for linux-list; Mon, 13 Mar 2000 00:29:57 -0800 (PST) mail_from (owner-linux@relay.engr.sgi.com) Received: from sgi.com (sgi.engr.sgi.com [192.26.80.37]) by cthulhu.engr.sgi.com (980427.SGI.8.8.8/970903.SGI.AUTOCF) via ESMTP id AAA14959 for ; Mon, 13 Mar 2000 00:29:53 -0800 (PST) mail_from (kevink@mips.com) Received: from mx.mips.com (mx.mips.com [206.31.31.226]) by sgi.com (980327.SGI.8.8.8-aspam/980304.SGI-aspam: SGI does not authorize the use of its proprietary systems or networks for unsolicited or bulk email from the Internet.) via ESMTP id AAA04390 for ; Mon, 13 Mar 2000 00:29:53 -0800 (PST) mail_from (kevink@mips.com) Received: from newman.mips.com (newman [206.31.31.8]) by mx.mips.com (8.9.3/8.9.0) with ESMTP id AAA13762; Mon, 13 Mar 2000 00:29:51 -0800 (PST) Received: from satanas (satanas [192.168.236.12]) by newman.mips.com (8.9.3/8.9.0) with SMTP id AAA12558; Mon, 13 Mar 2000 00:29:49 -0800 (PST) Message-ID: <002701bf8cc6$c2ef0200$0ceca8c0@satanas.mips.com> From: "Kevin D. Kissell" To: "Harald Koerfgen" Cc: , , "Linux SGI" Subject: Re: FP emulation patch available Date: Mon, 13 Mar 2000 09:33:02 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.3110.5 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-linuxmips@oss.sgi.com Precedence: bulk Return-Path: X-Orcpt: rfc822;linuxmips-outgoing As Ralf just reminded me by email, the Algorithmics/MIPS kernel FPU emulator is *not* SMP-safe. It borrows an existing (if seldom used) exception handler, and has only a single set of emulated FPU registers. I sort-of knew this, but had not worried about it, since to the best of my knowledge no one is building (or has built) SMP MIPS machines out of FPU-less processors. Nevertheless, a compile-time test, to blow up on any attempt at an SMP build of the emulator should always have been there, and is going in right away. Does anyone out there actually need/want an SMP version of the emulator? It's not completely trivial, but it would not be all that difficult to do... Regards, Kevin K. __ Kevin D. Kissell MIPS Technologies European Architecture Lab kevink@mips.com Tel. +33.4.78.38.70.67 FAX. +33.4.78.38.70.68 From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <002701bf8cc6$c2ef0200$0ceca8c0@satanas.mips.com> From: "Kevin D. Kissell" Subject: Re: FP emulation patch available Date: Mon, 13 Mar 2000 09:33:02 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linuxmips@oss.sgi.com Return-Path: To: Harald Koerfgen Cc: linux-mips@vger.rutgers.edu, linux-mips@fnet.fr, Linux SGI Message-ID: <20000313083302.SJCbRadcz5EXALtR_hXWH1jwVepq9u5SfcZg74EVNDE@z> As Ralf just reminded me by email, the Algorithmics/MIPS kernel FPU emulator is *not* SMP-safe. It borrows an existing (if seldom used) exception handler, and has only a single set of emulated FPU registers. I sort-of knew this, but had not worried about it, since to the best of my knowledge no one is building (or has built) SMP MIPS machines out of FPU-less processors. Nevertheless, a compile-time test, to blow up on any attempt at an SMP build of the emulator should always have been there, and is going in right away. Does anyone out there actually need/want an SMP version of the emulator? It's not completely trivial, but it would not be all that difficult to do... Regards, Kevin K. __ Kevin D. Kissell MIPS Technologies European Architecture Lab kevink@mips.com Tel. +33.4.78.38.70.67 FAX. +33.4.78.38.70.68