Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 17 May 1996 14:18:20 -0700 (MST)
From:      Terry Lambert <terry@lambert.org>
To:        toor@dyson.iquest.net (John S. Dyson)
Cc:        alc@cs.rice.edu, questions@freebsd.org
Subject:   Re: Size of the Virtual Memory Page
Message-ID:  <199605172118.OAA20724@phaeton.artisoft.com>
In-Reply-To: <199605160522.AAA00186@dyson.iquest.net> from "John S. Dyson" at May 16, 96 00:22:53 am

next in thread | previous in thread | raw e-mail | index | archive | help
> > 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.

If you do this, *PLEASE* bracket the code with compile-time disablers
so I don't have to support 16k pages on the PPC.  Thanks.


					Terry Lambert
					terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199605172118.OAA20724>