Path: utzoo!utgpu!attcan!uunet!lll-winken!ames!killer!pollux!ti-csl!m2!holland
From: holland@m2.csc.ti.com (Fred Hollander)
Newsgroups: comp.sys.mac
Subject: Re: Virtual Memory INIT
Message-ID: <67990@ti-csl.CSNET>
Date: 23 Jan 89 19:57:28 GMT
References: <8901151644.AA17944@Portia.stanford.edu> <870@mailrus.cc.umich.edu> <2598@cxsea.UUCP>
Sender: news@ti-csl.CSNET
Reply-To: holland@m2.UUCP (Fred Hollander)
Organization: TI Computer Science Center, Dallas
Lines: 32

In article <2598@cxsea.UUCP> blm@cxsea.UUCP (Brian Matthews) writes:
>Shane Looker (shane@chablis.cc.umich.edu) writes:
>|In article <8901151644.AA17944@Portia.stanford.edu> name@PORTIA.STANFORD.EDU (tony cooper) writes:
>|> What would you do with all that
>|>much memory? I guess you could use it as a RAM disk!?!
>|
>|I sure hope you are joking about this...
>
>I don't know if Tony was joking or not, but I would certainly consider
>using the extra memory as a RAM disk.  In fact, I have a paged RAM disk
>on my Unix machine.
>
>out.  In the worst case, when the application grows larger than physical
>memory, the RAM disk will work like a normal drive.  But even in this

I don't think so.  First the pages of the RAM disk (now on disk) need to be
paged into RAM, then another RAM access for the application to get the data.
It would certainly be faster to read directly off the disk.  I also don't
believe that this worst case situtation will be that rare.  You seem to be
thinking of a single application in memory.  We're not talking about paging
entire applications, but, small blocks (1-2K).  So, the RAM disk will be paged
out just as often as any other block that is not used frequently/recently.

But seriously, with all the system patches, there's a lot of unused ROM code.
How about paging that to disk :).

Fred Hollander
Computer Science Center
Texas Instruments, Inc.
holland%ti-csl@csnet-rela

The above statements are my own and not representative of Texas Instruments.