Subject: Re: Building an alternate backing store.
To: gabriel rosenkoetter <>
From: Roger Brooks <>
List: tech-kern
Date: 07/14/2000 10:46:03
On Thu, 13 Jul 2000, gabriel rosenkoetter wrote:

>Just to clarify, the cloud's-eye view of what I want to do is this:
>The swap pager decides it's time to page out a process. It would
>ordinarily do this by writing it to swap space on disk. In my cluster
>(yes, I know there are many details of the cluster I'm eliding;
>they'll be dealt with later and maybe by others), however, I want the
>swap pager to *first* page to pages resident in another machine's
>memory. The premise is that network transfer speeds exceed disk
>access speeds, and are rising at a greater rate (especially on the
>commodity hardware involved).
>Figure that the above has already happened through the (in)appropriate
>voodoo, and we now page fault into this page that, instead of having
>been transfered to swap, has been transfered to another machine.
>Obviously, looking for it in swap is futile; we need to ask the other
>machine to give it back. That's the step I'm trying to stomp on (the
>asking swap for it) with my own routines (the asking the other machine
>for it).

Surely this is not too different with what happens when a system is
booted diskless with an NFS-mounted swap file?


Roger Brooks (Systems Programmer),          |  Email:
Computing Services Dept,                    |  Tel:   +44 151 794 4441
The University of Liverpool,                |  Fax:   +44 151 794 4442
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