[petsc-dev] significance of version numbers

[Satish Balay]

On Sat, 6 Mar 2010, Jed Brown wrote:

> On Sat, 6 Mar 2010 13:09:57 -0600 (CST), Satish Balay <balay at mcs.anl.gov> wrote:
> > And we never land at the orignial-intended convention you are refering
> > to. Perhaps one rationale used was: Currently linux-kernel only
> > changes the sub-minor version for any and all changes - so current
> > petsc scheme is equivalent, [instead of .p1,.p2, linux kernel uses an
> > extra .1,.2 etc..]  and no need for petsc to adhere to the original
> > convention.
> 
> The Linux 2.4 to 2.6 transition broke almost everything that depended on
> kernel interfaces (e.g. device drivers) and moved certain functionality
> to an entirely different system (e.g sysfs).  This could certainly have
> been called 3.0, but they chose 2.6 and it seems entirely possible that
> all future releases will be 2.6.x.  Linux uses the y in 2.6.x.y for
> fully compatible updates (mainly just bug fixes), so it's essentially
> one decimal removed from the standard convention.

What I meant to say is: [if you ignore 2.3.2->3.0.0 jump] PETSc also
complies with the same logic. You can say - petsc uses the eqivalent
3.0.x.py notation.


>  They wouldn't release 2.8.0 unless there was a redesign of
> comparable size to 2.4 -> 2.6.

> > [Also as you indicate - gnome also doesn't conform - by removing
> > subminor release number]
> 
> Actually, I think they do conform in the sense that they never put
> ABI-incompatible changes in a subminor release.  Since they never make
> releases of any sort that preserve ABI compatibility, they don't bother
> with the extra decimal place since the subminor would always be 0.
> 
> > Are you sugesting going from:
> > 
> > petsc-3.0.0-p0.tar.gz
> > petsc-3.0.0-p1.tar.gz
> > 
> >  to:
> > 
> > petsc-3.1.0-p0.tar.gz
> > or
> > petsc-3.1-p0.tar.gz
> 
> Yes, and if the next release happened to preserve ABI compatibility,
> then it would be called 3.1.1-p0.

We've given up on preserving ABI changes in releases a long-long
time. So the above is not likely to happen. [even of there are no ABI
changes - we will not flag it as so - as we won't know for sure..]

> > The alternative - not suggested is:
> > petsc-3.1.0.tar.gz
> > petsc-3.1.1.tar.gz
> > etc..
> 
> This would be okay, but I wasn't suggesting this because subminor has
> the connotation that it may introduce new functionality, which a patch
> level never does.

Well petsc patches are now becoming more than just bug fixes. [they
are generally minor fixes - could be additional functionality].

Satish

> 
> > Any change is bound to create some confusion with users..
> 
> I don't see 3.1.0-p0 instead of 3.0.1-p0 causing any confusion, and
> would eliminate confusion of anyone not familiar with PETSc wondering
> why interfaces have changed relative to 3.0.0.
> 
> Jed
>