Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!ucsd!sdcsvax!jsb@actnyc.uucp
From: jsb@actnyc.uucp (The Invisible Man)
Newsgroups: comp.os.research
Subject: Re: working sets and shared pages
Message-ID: <4787@sdcsvax.UCSD.EDU>
Date: 22 Mar 88 22:03:15 GMT
Sender: nobody@sdcsvax.UCSD.EDU
Organization: Diet Software
Lines: 31
Approved: comp-os-research@ucsd.edu

In article <4780@sdcsvax.UCSD.EDU> ijh@tut.fi (Ilkka Haikala) writes:
)You requested information about DWS-implementations in environments,
)where segments are shared between processes. I know about three or two
)such implementations:
)
)1. Nokia Electronics (a Finish company) is manufacturing an Ada
) /* details deleted */

)2. The MUMS project in university of Lund (Sweden) is implementing a
) /* details deleted */
 
)3. The DWS-implementation for Gould superminis has been described in
) /* details deleted */

)P.S. If you have knowledge about some other systems, I would be most
)greatful to get the references.

4. The Auragen system (partially described in the 9th ACM Symposium on
   Operating Systems Principals) did the following:
   Each process had its own set of page mapping registers which included
   fields for per page reference history thus working sets could be calculated
   independant of sharing.  A page in any processes working set would remain
   in memory but a process sharing the page but not having it in its working
   set would think it was paged out.  The page fault handler would check if
   the faulted page was really in memory before bringing it in from disk.
   The per process history information and the check for whether a page fault
   required disk access were the only changes necessary for working set
   maintenance in a shared environment.
-- 
			The check is in the e-mail

				jim (uunet!actnyc!jsb)