[pypy-dev] support for 64-bit processors and eliminating global state
jonah at eecs.berkeley.edu
Wed Sep 30 18:27:55 CEST 2009
I'm new to pypy but would encourage the development folks to apply some
focus towards two things: support for both 32 and 64-bit processors and
eliminating global state including the GIL.
The near future of mainstream processors is multi-core x86_64. For the
short-term both 32-bit and 64-bit platforms will be around. Code that
makes "naked" assumptions about word size will break and needs to be
re-factored to hide the word-size dependencies. Similarly code that
assumes a single thread of execution or uses a GIL to protect global
state will make efficient use of modern processors. Any language or
system that cannot make the transition to 64-bit multi-core will start
to loose ground to those that do.
At the Parallel Computing Laboratory (UC Berkeley) one of the projects
we are working on is called SEJITS which stands for Selective Embedded
Just in Time Specialization. The idea is that one can extend a
self-introspecting modern scripting language for calling native coded
modules (e.g. C) at selected points for handling specialized operations
(e.g. vector/matrix operations using tuned SIMD or CUDA code). You can
see the abstract of a recent SEJITS paper at
http://pmea.ac.upc.edu/program.html (session 1a) but unfortunately the
paper is not online yet.
Both Python and Ruby are being looked at as potential target languages
for SEJITS work. Both have sufficient introspection facilities to
support selective JIT operations. Python has an advantage in having
been used by the scientific community for longer than Ruby with more
established users. I'd love to see this work integrate with pypy. At
the moment the folks involved are targeting CPython.
In any case, I think the transition to multi-core/multi-threaded 64-bit
machines is a potential watershed of major importance which it would
behoove pypy-dev folks to keep in mind.
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