[Python-Dev] PyDict_SetItem hook (original) (raw)

Jeffrey Yasskin jyasskin at gmail.com
Fri Apr 3 22:17:37 CEST 2009

On Fri, Apr 3, 2009 at 12:28 PM, Michael Foord <fuzzyman at voidspace.org.uk> wrote:

Collin Winter wrote:

On Fri, Apr 3, 2009 at 2:27 AM, Antoine Pitrou <solipsis at pitrou.net> wrote:

Thomas Wouters <thomas python.org> writes:

Pystone is pretty much a useless benchmark. If it measures anything, it's the speed of the bytecode dispatcher (and it doesn't measure it particularly well.) PyBench isn't any better, in my experience. I don't think pybench is useless. It gives a lot of performance data about crucial internal operations of the interpreter. It is of course very little real-world, but conversely makes you know immediately where a performance regression has happened. (by contrast, if you witness a regression in a high-level benchmark, you still have a lot of investigation to do to find out where exactly something bad happened) Perhaps someone should start maintaining a suite of benchmarks, high-level and low-level; we currently have them all scattered around (pybench, pystone, stringbench, richard, iobench, and the various Unladen Swallow benchmarks; not to mention other third-party stuff that can be found in e.g. the Computer Language Shootout). Already in the works :) As part of the common standard library and test suite that we agreed on at the PyCon language summit last week, we're going to include a common benchmark suite that all Python implementations can share. This is still some months off, though, so there'll be plenty of time to bikeshed^Wrationally discuss which benchmarks should go in there. Where is the right place for us to discuss this common benchmark and test suite?

Dunno. Here, by default, but I'd subscribe to a tests-sig or commonlibrary-sig or benchmark-sig if one were created.

As the benchmark is developed I would like to ensure it can run on IronPython.

We want to ensure the same thing for the current unladen swallow suite. If you find ways it currently doesn't, send us patches (until we get it moved to the common library repository at which point you'll be able to submit changes yourself). You should be able to check out http://unladen-swallow.googlecode.com/svn/tests independently of the rest of the repository. Follow the instructions at http://code.google.com/p/unladen-swallow/wiki/Benchmarks to run benchmarks though perf.py. You'll probably want to select benchmarks individually rather than accepting the default of "all" because it's currently not very resilient to tests that don't run on one of the comparison pythons.

Personally, I'd be quite happy moving our performance tests into the main python repository before the big library+tests move, but I don't know what directory to put it in, and I don't know what Collin+Thomas think of that.

The test suite changes will need some discussion as well - Jython and IronPython (and probably PyPy) have almost identical changes to tests that currently rely on deterministic finalisation (reference counting) so it makes sense to test changes on both platforms and commit a single solution.

IMHO, any place in the test suite that relies on deterministic finalization but isn't explicitly testing that CPython-specific feature is a bug and should be fixed, even before we export it to the new repository.

Jeffrey

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