From owner-freebsd-alpha Thu May 9 1:46:27 2002 Delivered-To: freebsd-alpha@freebsd.org Received: from finch-post-11.mail.demon.net (finch-post-11.mail.demon.net [194.217.242.39]) by hub.freebsd.org (Postfix) with ESMTP id 9AD4137B40A; Thu, 9 May 2002 01:46:21 -0700 (PDT) Received: from mailgate.nlsystems.com ([62.49.251.130] helo=herring.nlsystems.com) by finch-post-11.mail.demon.net with esmtp (Exim 3.35 #1) id 175jYg-0001FS-0B; Thu, 09 May 2002 08:45:54 +0000 Received: from herring.nlsystems.com (localhost [127.0.0.1]) by herring.nlsystems.com (8.12.3/8.11.2) with ESMTP id g498jkvN062750; Thu, 9 May 2002 09:45:46 +0100 (BST) (envelope-from dfr@herring.nlsystems.com) Received: (from dfr@localhost) by herring.nlsystems.com (8.12.3/8.12.3/Submit) id g498jehK062749; Thu, 9 May 2002 09:45:40 +0100 (BST) Content-Type: text/plain; charset="iso-8859-1" From: Doug Rabson To: Terry Lambert , Andrew Gallatin Subject: Re: *bsd on srm-less alpha's Date: Thu, 9 May 2002 09:45:40 +0100 User-Agent: KMail/1.4.1 Cc: John Baldwin , freebsd-alpha@FreeBSD.ORG References: <3CD8BADE.D7D0FC8C@mindspring.com> <15577.7766.160517.751366@grasshopper.cs.duke.edu> <3CD97001.89254E73@mindspring.com> In-Reply-To: <3CD97001.89254E73@mindspring.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Message-Id: <200205090945.40777.dfr@nlsystems.com> Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Wednesday 08 May 2002 7:35 pm, Terry Lambert wrote: > Andrew Gallatin wrote: > > He's talking about using MILO, which, at least as of 2.1.13, uses the > > OSF PALcode. What nobody knows is if the PALcode in milo is close > > enough to the "real" OSF PALcode used by the SRM for it to be usable > > by FreeBSD. It certainly seems close, as it has the text "SRM" and > > "OSF" littered all over it. > > > > Now, I've heard various people talk about how we need certain VM > > related PALcode functions that aren't avalable in the MILO palcode, > > However, nobody has mentioned exactly which function this is, and I > > think this might be an urban legend. > > I used to know this. I can describe it in general terms. Linux > has abstracted its translation lookaside so that it can handle it > in software for those processors, like MIPS, which require it. > FreeBSD tries much harder to get the processor to do the work, and > is less abstract. THis means that FreeBSD gets higher performance > on platforms where hardware assitance is possible. Terry, I have no idea what you are talking about here. The TLB on alphas = is=20 always managed by the PALcode. You can't do it anywhere else. The linux=20 kernel code doesn't try to manage TLBs and neither do we. The PALcode TLB= =20 miss handler parses the page tables (which are in standard OSF hierarchic= al=20 form for both FreeBSD and Linux) and inserts the TLB entry. The os doesn'= t=20 play any part in this process. --=20 Doug Rabson=09=09=09=09Mail: dfr@nlsystems.com =09=09=09=09=09Phone: +44 20 8348 6160 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message