Re: [Qemu-devel] Qemu stable releases

[Richard W.M. Jones]

On Fri, Dec 09, 2011 at 07:25:39AM -0600, Anthony Liguori wrote:
> On 12/09/2011 06:01 AM, Richard W.M. Jones wrote:
> >On Fri, Dec 09, 2011 at 10:39:37AM +0000, Richard W.M. Jones wrote:
> >>FWIW in libguestfs we have such a policy.  Every few weeks I evaluate
> >>_all_ commits along the development branch and cherry pick those that
> >>meet this policy back to the stable branch, followed by making a new
> >>stable release.  Here is the policy:
> >>
> >>http://libguestfs.org/guestfs.3.html#libguestfs_version_numbers
> >>   from "Our criteria for backporting changes are ..."
> 
> Out of curiosity, what's the commit rate for libguestfs and what's
> the release schedule?

A lot less than qemu.  I can't update my qemu.git at the moment but
there are 810 commits in libguestfs since 2010-12-31, and maybe 50x as
many in qemu over the same period.

Release schedule is not fixed, but it seems to average to a new stable
branch every 3-4 months.

> I tried this years ago with QEMU and while it resulted in a very
> active stable branch, it was a huge amount of work, particularly as
> we got about half way through the next development cycle.

I generally don't backport fixes if the cherry picking involves
complicated changes, because that's against the policy that fixes in
the stable branch need to be well-tested and uncontroversial.  A
massive cherry pick rewrite is by definition not a well-tested change.

Splitting development commits helps: eg. if new features are split
into non-functional code motion commits + new feature commits.  We
tend to backport code motion changes, which helps to make cherry
picking bug fixes simpler because the code in both branches stays
similar.

Anyhow, there you go, it may not work for qemu.

Rich.

-- 
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