Re: [Hackathon Minutes] Xen 4.4 Planning

[George Dunlap <george.dunlap@eu.citrix.com>]

On 13/06/13 15:00, Lars Kurth wrote:
> This took me a while to post, but given that we are not starting 4.4 
> just yet, this may be appropriate now. I may have misrepresented some 
> stuff as it has been 4 weeks since I wrote these.
> Cheers
> Lars
>
> = Purpose of Roadmap =
> * Set a vision for interesting features
> * Track items
> * Help consumers of Xen with their planning
>
> = Release Models that work well =
> There was a brief discussion on two different release models
> * Train leaves the station (Linux)
> * Release when ready (Debian)
>
> == Stefano's Proposal ==
> We should aim to reduce the release cycle to 4 months (or maybe 6 
> months as an intermediate step) from the current 9 months. A 4 months 
> relase cycle should help accelerate development and lead to fewer 
> patches being queued up. The implications are that we would have to 
> operate a 2-3 weeks merge window.
>
> To do this, we would need to resolve a number of issues
> * It is likely that code reviews for such a short merge window would 
> become a bottleneck. We are not sure whether this would be a major 
> issue : the review bandwith would depend on the patches submitted (and 
> their complexity)
> * [I can't remember who raised this] The concern was raised that we 
> would not have enough x86 Xen reviewers got a 2-3 weeks merge window
> * [Konrad] Stated that in PVOPS for Linux contributions we don't have 
> a review bottleneck, but we should make sure that the Xen and 
> PVOPS/Linux merge window don't overlap (as this would require the same 
> set of people to review patches in two projects)
> * The rest of the time (approx 3 months) would be used for stabilizing 
> the release

Why would we need 3 months to do testing for 2 weeks of merging (or 4 
months of development, depending on how you look at it), when 6 weeks 
has been just about right for 9 months of "merging"?

I think it takes that long for Linux because it's such a gigantic 
project.  I would think 3 months development / 1 month stabilization 
would be OK for Xen.

I would rather avoid the "merge window" workflow until it becomes really 
necessary, as it adds all kinds of other issues (e.g., needing something 
like linux-next to detect and sort out merge conflicts ahead of the 
merge window).

  -George