Hey Maciej, On Thu, Feb 11, 2010 at 6:39 AM, Maciej Fijalkowski <fij...@gmail.com> wrote: > Snippet from: > > http://codereview.appspot.com/186247/diff2/5014:8003/7002 > > *PyPy*: PyPy [#pypy]_ has good performance on numerical code, but is > slower than Unladen Swallow on non-numerical workloads. PyPy only > supports 32-bit x86 code generation. It has poor support for CPython > extension modules, making migration for large applications > prohibitively expensive. > > That part at the very least has some sort of personal opinion > "prohibitively",
Of course; difficulty is always in the eye of the person doing the work. Simply put, PyPy is not a drop-in replacement for CPython: there is no embedding API, much less the same one exported by CPython; important libraries, such as MySQLdb and pycrypto, do not build against PyPy; PyPy is 32-bit x86 only. All of these problems can be overcome with enough time/effort/money, but I think you'd agree that, if all I'm trying to do is speed up my application, adding a new x86-64 backend or implementing support for CPython extension modules is certainly north of "prohibitively expensive". I stand by that wording. I'm willing to enumerate all of PyPy's deficiencies in this regard in the PEP, rather than the current vaguer wording, if you'd prefer. > while the other part is not completely true "slower > than US on non-numerical workloads". Fancy providing a proof for that? > I'm well aware that there are benchmarks on which PyPy is slower than > CPython or US, however, I would like a bit more weighted opinion in > the PEP. Based on the benchmarks you're running at http://codespeak.net:8099/plotsummary.html, PyPy is slower than CPython on many non-numerical workloads, which Unladen Swallow is faster than CPython at. Looking at the benchmarks there at which PyPy is faster than CPython, they are primarily numerical; this was the basis for the wording in the PEP. My own recent benchmarking of PyPy and Unladen Swallow (both trunk; PyPy wouldn't run some benchmarks): | Benchmark | PyPy | Unladen | Change | +==============+=======+=========+=================+ | ai | 0.61 | 0.51 | 1.1921x faster | | django | 0.68 | 0.8 | 1.1898x slower | | float | 0.03 | 0.07 | 2.7108x slower | | html5lib | 20.04 | 16.42 | 1.2201x faster | | pickle | 17.7 | 1.09 | 16.2465x faster | | rietveld | 1.09 | 0.59 | 1.8597x faster | | slowpickle | 0.43 | 0.56 | 1.2956x slower | | slowspitfire | 2.5 | 0.63 | 3.9853x faster | | slowunpickle | 0.26 | 0.27 | 1.0585x slower | | unpickle | 28.45 | 0.78 | 36.6427x faster | I'm happy to change the wording to "slower than US on some workloads". Thanks, Collin Winter _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
