Re: [PATCH 0/15] Nested Virtualization: Overview

[Keir Fraser <keir.fraser@eu.citrix.com>]

On 04/06/2010 10:44, "Christoph Egger" <Christoph.Egger@amd.com> wrote:

> @Tim: On last review you asked about the use of MAX_NESTEDP2M.
> Actually, this is a hack. What I really need in Xen is a generic pool
> implementation like this
> http://netbsd.gw.com/cgi-bin/man-cgi?pool+9+NetBSD-current
> and this
> http://netbsd.gw.com/cgi-bin/man-cgi?pool_cache+9+NetBSD-current
> In NetBSD, pool_cache(9) is implemented on top of pool(9).
> 
> IMO, xmalloc/xfree, machine check and cpupool code should also
> use pool_cache(9) in Xen instead of having their own versions.
> Can we take the pool/pool_cache code from NetBSD ?

I'd hope we can really manage without such a mechanism. At least, we'd need
a darn good reason for it, and to have rejected simpler alternative
solutions. I know some OSes have such a concept so that paging code doesn't
deadlock. I can't immediately guess why we'd need it in Xen.

And does pool_cache have much relationship to cpupool, except both have
"pool" in their name? :-)

 -- Keir