1. Problem.
Last week I successfully built Rakudo Star from source on two different
Linux/i386 machines, one real, one virtual. However, my attempt to
build Rakudo Star on my iBook was unsuccessful. It repeatedly failed at
this point:
/Users/jimk/work/rstar/rakudo-star-2010.07/install/bin/parrot
src/gen/perl6.pbc --target=pir \
src/gen/core.pm > src/gen/core.pir
I filed an RT for this:
http://rt.perl.org/rt3//Ticket/Display.html?id=76828.
In the course of discussion in that ticket, I noted that I had been able
to build Perl 6 on top of Parrot on that same machine at least as late
as June 2008, when I led a workshop to do that at YAPC::NA in Chicago.
Coke responded that the file where compilation failed was "the single
largest compilation that occurs during the process, and requires a LOT
of memory, and it's likely gotten bigger since the last time you ran."
I have 256 MB of physical memory available on this machine, to which
Coke responded, "Based on recent history, I think 1G is the minimum
recommend memory for building rakudo (for that file in particular)."
2. General Issue.
I recapitulate this discussion here because this is an issue that both
the Parrot and Rakudo development teams will have to address: What are
the memory (and other) requirements for building Perl 6 on Parrot?
3. Disposal of Red Herring; A Bit of History.
To be frank, one approach would be to say, "kid51, your iBook is six
years old -- ancient in computer years. You're the only one still
submitting smolder tests for Darwin/PPC. Go out and buy a new one and
throw that G4 away."
You could say that, but of course I would not do that. I am
tempermentally the kind of person who keeps hardware running as long as
possible.
But more to the point, this kind of computer is where we came in! When
the Parrot project was born nine years ago, this kind of computer -- and
more importantly, computers with this size memory -- was state of the
art. It was what the original Parrot developers would have been using.
(ISTR being told at YAPC::NA::2002 in St Louis that Apple had given
iBooks to "the Perl 6 development team." They certainly seemed to be
ubiquitous at that conference.)
So, if we were to turn away from building Rakudo Star on a box of this
size, we would be saying, "We can't build Perl 6 on the machines on
which we started out to write Perl 6." To me, that's a very sub-optimal
solution.
4. Current Issues.
In the days since Rakudo Star was released, critics have taken Rakudo
Star to task for (a) a slower start-up time than Perl 5; and (b) a
slower total runtime than Perl 5. We have acknowledged those concerns
-- and have done so for a long time -- but have argued that we want to
get things right before we optimize for speed.
But we've had much less focus on memory usage and apparently none on the
amount of memory needed to *build* Rakudo (as distinct from the amount
needed to *run* Rakudo). My hunch is that most Parrot and Rakudo
developers are, unlike me, early adopters of hardware that has come with
vastly greater amounts of memory than mine, and therefore have never
been bitten by the amount of memory needed to build Rakudo.
5. A New Goal and Obstacles to Achieving It.
I think that lowering the memory required to build Rakudo ought to be an
explicit goal of both Parrot and Rakudo. *Do you agree?*
If so, then we have to prioritize efforts to reach this goal and herd
our developer cats in the direction of a solution. And, to complicate
matters, we have to recognize that this will be exponentially harder
because it will require changes in both Parrot and Rakudo. Both will be
difficult. Parrot will have to shrink its memory footprint. And Coke
has suggested on IRC that the file in Rakudo which failed to compile is
one of the biggest and most difficult in that distribution.
Furthermore, the sort of changes that are needed are way out of my
personal area of expertise.
6. Incentive.
But perhaps I can offer an incentive! I am prepared to offer a prize of
US$200 (total), payable in cash or in beer, to the person or persons who
enable Perl 6 to once again build on Rakudo Star on my iBook G4.
Stipulations: We're talking about Rakudo Star here; not the monthly
Rakudo compiler releases. Cet. par., we'll assume that the solution
lies partly in Parrot and partly in Rakudo and, hence, the prize will be
shared. The winner of the Parrot part of the prize will be decided in
#parrotsketch. The winner of the Rakudo part will be decided in
whatever is Rakudo's equivalent to #parrotsketch. And I will be the
person who decides whether Rakudo Star has actually successfully built
on my laptop.
Any takers?
Thank you very much.
kid51
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