From owner-freebsd-questions Wed May 15 22:23:01 1996 Return-Path: owner-questions Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id WAA25219 for questions-outgoing; Wed, 15 May 1996 22:23:01 -0700 (PDT) Received: from dyson.iquest.net (dyson.iquest.net [198.70.144.127]) by freefall.freebsd.org (8.7.3/8.7.3) with ESMTP id WAA25211 for ; Wed, 15 May 1996 22:22:59 -0700 (PDT) Received: (from root@localhost) by dyson.iquest.net (8.7.5/8.6.9) id AAA00186; Thu, 16 May 1996 00:22:53 -0500 (EST) From: "John S. Dyson" Message-Id: <199605160522.AAA00186@dyson.iquest.net> Subject: Re: Size of the Virtual Memory Page To: alc@cs.rice.edu (Alan Cox) Date: Thu, 16 May 1996 00:22:53 -0500 (EST) Cc: questions@FreeBSD.ORG In-Reply-To: <199605160402.XAA00946@noel.cs.rice.edu> from "Alan Cox" at May 15, 96 11:02:12 pm X-Mailer: ELM [version 2.4 PL24 ME8] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-questions@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > > P.S. Theoretically, you could do the same thing on the x86. John (Dyson), > have you ever thought of trying this just for grins? Some stuff would likely > break, but... :-) > I have thought about it (in passing.) Actually, it could decrease overhead in some cases, at the expense of memory. 8/16K pages *might* be interesting. The VM and vfs_bio system (after my changes) will have problems with bigger than 16K pages. I am sure that they could be worked around. The limitation has to do with the bit-mask that I use for valid and dirtyness being in 512 byte increments. We have 32bits/word, so that means that 16K is kind of the max (if you ignore long-longs.) Long-longs would bring it up to 32K. I would guess that 64K might be cool also, but require a few changes. John