Re: [LSF/MM TOPIC] VM containers

From: Aneesh Kumar K.V
Date: Thu Jan 28 2016 - 10:23:12 EST


Rik van Riel <riel@xxxxxxxxxx> writes:

> Hi,
>
> I am trying to gauge interest in discussing VM containers at the LSF/MM
> summit this year. Projects like ClearLinux, Qubes, and others are all
> trying to use virtual machines as better isolated containers.
>
> That changes some of the goals the memory management subsystem has,
> from "use all the resources effectively" to "use as few resources as
> necessary, in case the host needs the memory for something else".
>
> These VMs could be as small as running just one application, so this
> goes a little further than simply trying to squeeze more virtual
> machines into a system with frontswap and cleancache.
>
> Single-application VM sandboxes could also get their data differently,
> using (partial) host filesystem passthrough, instead of a virtual
> block device. This may change the relative utility of caching data
> inside the guest page cache, versus freeing up that memory and
> allowing the host to use it to cache things.
>
> Are people interested in discussing this at LSF/MM, or is it better
> saved for a different forum?
>

I am interested in the topic. We did look at doing something similar on
ppc64 and most of our focus was in reducing boot time by cutting out the
overhead of guest bios (SLOF) and block layer (by using 9pfs). I would
like to understand the MM challenges you have identified.

-aneesh