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From: "John S. Dyson" <toor@dyson.iquest.net>
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Subject: Re: help with fstat?
In-Reply-To: <199710292004.NAA17154@usr07.primenet.com> from Terry Lambert at "Oct 29, 97 08:04:04 pm"
To: tlambert@primenet.com (Terry Lambert)
Date: Wed, 29 Oct 1997 17:54:27 -0500 (EST)
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        angio@angio.net, perlsta@cs.sunyit.edu, hackers@FreeBSD.ORG
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Terry Lambert said:
> 
> Ideally, there would never be more than two pages in a MADV_SEQUENTIAL
> marked region in real memory or swap at any one time:  The page that
> was previously accessed, and the page that was just accessed.
> 
> 
> Really, I want per object working set quotas, and I want MADV_SEQUENTIAL
> to set the quota on the backing object to two pages, but that's more of
> an implementation detail.
> 
I don't think that working set quotas are necessarily a good idea.  The
term "working set quota" is an interesting one anyway.  Do you mean in-memory
quota or mapped quota???  Our MADV_SEQUENTIAL mode attempts to deactivate
or cache read pages.  Cached pages are fair game.  This whole thing starts
bringing up the spectre of working set mgmt, and the folly of VMS and NT.

PS.  Terry, have you actually tried the sequential mode that we use?


-- 
John
dyson@freebsd.org
jdyson@nc.com