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Date: Sat, 23 Aug 2003 10:54:18 -0400 (EDT)
From: Robert Watson <rwatson@FreeBSD.ORG>
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To: David Schultz <das@FreeBSD.ORG>
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cc: Nicolas Souchu <nsouch@free.fr>
cc: freebsd-arch@FreeBSD.ORG
Subject: Re: Loadable VM pager
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On Sat, 23 Aug 2003, David Schultz wrote:

> On Sat, Aug 16, 2003, Nicolas Souchu wrote:
> > I'm wondering if being able to load dynamically a pager in FreeBSD VM
> > would be worth and even possible with kobj. Of course that would
> > introduce some overhead to the page fault handling...
> 
> Presently, the VM code has a number of special cases based on pager
> type, and this organization does not lend itself well to object-oriented
> techniques.  At a minimum, those cases would have to be fixed, with
> consideration to the performance consequences.  It's an interesting
> idea, nonetheless... 

It would be nice if we could easily support research into DSM, etc, using
VM pagers.  This is one of the research-nice things that we lost in the
transition of the code from Mach (or maybe we got the code before Mach was
really into that sort of thing, don't know).  I agree that one of the key
issues will be avoiding slowing the fast path...

Robert N M Watson             FreeBSD Core Team, TrustedBSD Projects
robert@fledge.watson.org      Network Associates Laboratories