[pypy-dev] minimum system requirements, build configuration

[Armin Rigo]

Hi Dima,

On Tue, Apr 5, 2011 at 9:26 PM, Dima Tisnek <dimaqq at gmail.com> wrote:
> What I'm trying to say, is gc should adapt to run-time behaviour of a
> particular script, in some cases 16MB heap threshold would impact both
> user expectation and performance significantly.

It may impact user expectation and performance, but:

User expectation: so far we've considered the "desktop" users, which
do not care about 10MB versus 20MB but start to care when it's about
300MB versus 600MB.  It's true that other categories of users exist.
Sorry for not being able to care for all possible use cases at once
:-)

Performance: actually this setting of ours -- not collecting before we
have at least 16MB of data -- was done to avoid degradation of
performance in cases where the Python script has really low memory
usage, so the idea "it's consuming 30MB instead of 5MB so it must have
a terrible performance" sounds pretty abstract.  But again this is
assuming a system where 30MB is a small fraction of the total amount
of RAM.

If you want to care about the use case of, say, systems with 16MB of
RAM in total, then feel free to tweak PyPy.  I suppose that you'd get
the best results by tweaking one of our GCs, or writing a new one.
(For example it probably doesn't make much sense to have a nursery at
all.)


I hope this helps to clarify the issue,

Armin