Re: perf & rasd integration plan

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Tue, Oct 07, 2014 at 03:49:12PM +0200, Borislav Petkov escreveu:
> On Tue, Oct 07, 2014 at 10:40:21AM -0300, Arnaldo Carvalho de Melo wrote:
> > Right, we now should always think that the great advantage of having
> > this code and its users in the same repo tree is going away, i.e. we
> > will not be able to improve the code by fixing mistakes that require
> > changing its users.
> 
> Why? I mean, in the rasd case, changing function calling conventions as
> part of updating the perf libraries is no act. I mean, we won't link
> against a shared lib but build a static executable and thus the perf src
> lib (let's call it that - a source library) we're using is a don't care.

So you say that if we change a method, say, perf_evlist__open() to
accept a new argument, or change the type of one of its arguments,
with a good reason, it is acceptable and with just a change in the
README explaining why the build fails, which helps in finding how to fix
it in a particular project using these "source libraries" then it would
be ok?

That would be fine with me.

We should take care to make sure that the build _fails_ in such cases,
i.e.avoid changing the semantic of the Nth argument but keeping its type kind
of changes.

At some point there will be no more reasons to change things, and that
will be noticed by how long since the last change was made to a
particular class, at that point we may well think about making library
type promises.

- Arnaldo