[LLVMdev] [cfe-dev] [3.6 Release] RC3 has been tagged

Jack Howarth
2015-02-18T17:04:47Z

On Wed, Feb 18, 2015 at 11:53 AM, Renato Golin <renato.golin at
linaro.org> wrote:
> On 18 February 2015 at 16:39, Jack Howarth
> <howarth.mailing.lists at gmail.com> wrote:
>> This still all begs the question of what exact metrics exist for the
>> Q/A of llvm releases? IMHO, the bad PR from shoving out compiler
>> releases with severe performance regressions in the generated code far
>> outweighs a brief delay to triage these issues as much as possible.
>
> Hi Jack,
>
> It depends on how you interpret LLVM releases.
>
> I still see them as points in time where we actually did some deeper
> investigations as a community and made sure the compiler is still
> sane. If it's not, future points in time shall fix it, for example, on
> dot releases or next releases, depending on how severe the regression
> is.
>
> A while ago we kind of agreed on a release Go/NoGo table that was
> somewhat like this:
>
> Before release:
> * Any conformance regressions
> * Bad conformance breakage (new)
>
> Next dot release:
> * Any conformance breakage
> * Bad performance regression
>
> Next release:
> * Any performance regression
>
> Since most people use LLVM on top-of-tree, the problem of having a
> release that is not as good as the previous is somewhat washed away by
> the fact that we now have dot-releases, and can fix the horrible cases
> before a new full release comes in 6 months time.
>
> Also, we don't have a limit for dot releases, and last year we had a
> dot release almost right after the major release due to similar
> problems. So, what we release now won't necessarily go to
> distributions, if we continue the process on the next dot-release,
> 3.6.1.
>
> I think we all agree that this is a "bad performance regression",
but
> most of us think this is not bad enough to delay the release further,
> but probably bad enough to start the next dot release right after the
> end of this one.
>
> Does that really sound like such a bad idea?
>
> cheers,
> --renato

Renato,
       My concern is that, without strict enforcement of the triaging
serious P1-type bugs, the major  llvm.org releases will devolve into a
continual exchange of one set of major regressions for another set.
Strict enforcement of back porting the required fixes from later trunk
for point releases seem to require as just much effort and even more
due diligence than just defining certain types of bugs as release
blockers and dealing with them upfront. Otherwise, folks will decide
that the major releases are unsafe and eventually avoid them entirely.
               Jack