*BSD News Article 45501


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From: mercier@cinenet.net (Bob Mercier)
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: Can FreeBSD execute programs in the disk cache?
Date: 15 Jun 1995 21:51:25 GMT
Organization: Cinenet Communications,Internet Access,Los Angeles;310-301-4500
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Terry Lambert (terry@cs.weber.edu) wrote:
: Anssi.Saari@lmf.eua.ericsson.se (Anssi Saari) wrote:
: >
: > Well, can it? Yes or no will do.

: No.  It can only execute programs in the CPU.

: Much as your oven can't cook food in your fridge.


:                                         Terry Lambert
:                                         terry@cs.weber.edu
: ---
: Any opinions in this posting are my own and not those of my present
: or previous employers.

Well, this is a silly thread to go on and on about but I'd bet that,
on some disk controllers, it would be possible for the controllers cache
ram to appear in the host's address space.  With alot of work coordinating
between the VM system and the controller I bet the host could track
what disk pages where in the controller's cache at any given time.  It
would probably be good enough if you could simply tell the controller
when it was ok to release certain pages.  Another alternative would be
to disable caching on the controller and for the host to use the controller's
ram however it wanted.

Bob