Re: [PATCH v3 2/8] drm/i915: Adds graphic address space ballooning logic

Tvrtko Ursulin
2014-12-17T10:06:39Z

On 12/17/2014 05:20 AM, Tian, Kevin wrote:
> and if you read the paper referred in 1st mail, we call our ballooning as
> address space ballooning which is different from traditional ballooning
> technique used in memory virtualization, w/ the major difference as:
>
> * traditional ballooning only care about the size. As long as the desired
> number of pages can be ballooned out, we don't care whether they
> actually come from.
>
> * address space ballooning used in our case care about both size and
> address. We need the guest to balloon out a specified range of addresses
> as explained earlier.
>
> whether to grow/shrink dynamic is not the key difference between
> two approaches. yes, we only support static ballooning now at boot time,
> but the same interface can be extended to support dynamic ballooning
> in the future, w/ more cooperation from guest driver in the future.
>
> So I think using ballooning is a right fit here, though the policy is very
> simple now.

Personally I think the first part of the argument does not hold since
ballooning is the key word here - address space or memory makes little
difference to the metaphor. It is more like partitioning of blanking as
it stands.

You only get away with it since you hint of plans to make it dynamic in
the future. :)

Regards,

Tvrtko