Re: [9fans] Virtual memory in BSD and Plan9

[bwc@borf.com]

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I sense that this thread is about to enter the `Virtual address space is not
large enough to support the universe' phase.  Can we just insert a token
here and not actually issue the messages? :-)

  Brantley Coile

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From: "Douglas A. Gwyn" <DAGwyn@null.net>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] Virtual memory in BSD and Plan9
Date: Tue, 30 Oct 2001 15:22:01 GMT
Message-ID: <3BDDE974.C140716C@null.net>

rob pike wrote:
> I'm a radical here, but I think if a machine is paging, you've lost.
> To me, VM is a pretty technique for memory management in the kernel,
> something distinct from paging, which is a way to get the system
> through temprorary overshoots in memory demand.

Seems to me that computing has evolved toward a "caching" model.
E.g. a register set operating on a multilevel RAM cache, which
is a window into the RAM, which may be the window into a large
(memory-mapped) file, which may be a cached portion of some huge
database on the other end of a network connection.  Something
like "paging" (cache remapping) is needed or else a task would
be confined to a very narrow window forever..