Re: [Qemu-devel] Image streaming and live block copy (was: [PATCH 00/13] QED image streaming)

[Marcelo Tosatti <mtosatti@redhat.com>]

On Thu, Jun 16, 2011 at 11:38:48AM -0300, Marcelo Tosatti wrote:
> > People seem to agree on this, and the reason that I've heard why we
> > should merge the existing code instead is downstream time pressure. That
> > may be a valid reason for downstreams to add such code, but is taking
> > such code really the best option for upstream (and therefore long-term
> > for downstreams)?
> > 
> > If we take these patches as they are, I doubt that we'll ever get a
> > rewrite to implement the code as it should have been done in the first
> > place.
> 
> That (a newer, unified mechanism) is just a matter of allocating
> resources to the implementation.
> 
> At least in block copy's case the interface can be reused, so it can be
> seen as an incremental approach (read: advocating in favour of merging
> live block copy patchset).
> 
> > So I'm tempted to reject the current versions of both the image
> > streaming and live block copy series and leave it to downstreams to use
> > these as temporary solutions if the time pressure is too high. I know
> > that maintaining things downstream is painful, but that's the whole
> > point: I want to see the real implementation one day, and I'm afraid
> > this might be the only way to get it.

Again: there is no need to reject current live block copy
implementation, as image streaming implemented for generic image formats
is a strong motivator behind the unified implementation.