Re: Re: [PATCH][HVM] fix VNIF restore failure on HVMguestwith heavy workload

[Keir Fraser <keir@xensource.com>]

On 12/4/07 19:51, "Steven Hand" <Steven.Hand@cl.cam.ac.uk> wrote:

>> Any reason not to have the balloon driver write back to Xenstore if it's
>> used in this way.  Or is it just waiting for a patch to do that?
> 
> You also need xend to watch the node and update its internal structures,
> but otherwise that'd be fine.

We're not sure if this is even sensible in all cases. Should an admin memory
setting be overridable by a setting derived from the guest itself?

One sensible middle ground might be for the balloon driver to ignore the
memory-target field in xenstore if the balloon target has ever been
specified via /proc/xen/balloon. This would indicate that the guest is
taking control for its own memory setting and is a simple resolution of the
conflict over whose setting takes precedence. This might be good enough for
those people who would like us to keep the /proc/xen/balloon method (I was
considering killing it off entirely) -- I suspect people either want to
control their guest memory settings inside the guests *or* via 'xm mem-set':
not both.

 -- Keir