[Python-Dev] Yet another "A better story for multi-core Python" comment

[Armin Rigo]

Hi Gary,

On Tue, Sep 8, 2015 at 4:12 PM, Gary Robinson <garyrob at me.com> wrote:
> 1) More the reference counts away from data structures, so copy-on-write isn’t an issue.

A general note about PyPy --- sorry, it probably doesn't help your use
case because SciPy is not supported right now...

Right now, PyPy hits the same problem as CPython, despite not being
based on reference counting, because every major collection needs to
write flag bits inside the header of every object.  However, fixing
this issue is much more straightforward here: there are
well-documented ways that other virtual machines (for other languages)
already do.  Mostly, instead of writing one bit in the GC header, we'd
write one bit in some compact out-of-line array of bits.  Moreover, it
is an issue that we hear about every now and again, so we may
eventually just do it.


A bientôt,

Armin.