Subject: Re: Building an alternate backing store.
To: Roger Brooks <>
From: Darren Reed <>
List: tech-kern
Date: 07/14/2000 21:10:30
In some email I received from Roger Brooks, sie wrote:
> 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?

In addition to that, how about this:
- create a swap file on your networked host
- mmap it in
- mlock that memory in
- export that file via nfs as a swap file

or will that not do what I expect ?