[pypy-dev] pypy 2.2.1 performance on Raspian

[Maciej Fijalkowski]

do you have a link to those wrappers? Generally speaking using CPython
C API from PyPy is bound to be slow and there is not much we can do
about it (it's a miracle if it works at all)

On Wed, Jul 1, 2015 at 4:00 PM, Andy Baker <andy at pistuffing.co.uk> wrote:
> To clarify, these are python libraries, imported into the main python
> script.  It's these libraries that are just python library API wrappers for
> some underlyinig synchronous C code.  Had a quick browse a CFFI, but this
> seems more related to call 'C' directly from a Python scripts rather than
> 'wrapping' it up as a python library.  Since these libraries are not mine,
> I'd prefer to stay with the current model rather than discard the library
> wrapper and use CFFI instead.
>
> -----Original Message-----
> From: Andy Baker [mailto:andy at pistuffing.co.uk]
> Sent: 01 July 2015 14:15
> To: 'Cory Benfield'
> Cc: 'pypy-dev at python.org'
> Subject: RE: [pypy-dev] pypy 2.2.1 performance on Raspian
>
> Hi Cory,
>
> I didn't write the 'C' code or the Python wrappers myself but I have
> modified the 'C' source code and added new python wrapper function - they
> are for the Raspberry Pi RPiGPIO and RPIO hardware integration code.  The
> "wrappers" are very thin layers defining to the Cpython interpreter (or pypy
> JIT) how to map the Python call to the 'C' equvalent call along with
> exceptions and control of the GIL.  There's no state stored within this
> 'wrapper' code - the 'C' code blocks returning OK, or an error which raises
> a Python exception.  I'll look at CFFI to see if that sheds any light.
>
> Andy
>
> -----Original Message-----
> From: Cory Benfield [mailto:cory at lukasa.co.uk]
> Sent: 01 July 2015 13:48
> To: Andy Baker
> Cc: pypy-dev at python.org
> Subject: Re: [pypy-dev] pypy 2.2.1 performance on Raspian
>
>
>> On 1 Jul 2015, at 09:58, Andy Baker <andy at pistuffing.co.uk> wrote:
>>
>> I am trying pypy as a performance increase over CPython.  My code uses
> standard python libraries (not numpy), plus 2 'C' libraries accessing
> Raspberry Pi GPIO hardware with python wrappers.  I have compiled both with
> pypy (sudo pypy setup.py install).  The pypy version runs with no problems
> but is 2.5 times slower than CPython.  From the performance stats, I believe
> 2.2.1 should be on average 6 times faster.  I presume it's my 'C' python
> libraries which are the cause of the reduced performance.  What do I need to
> do to make these private libraries pypy compatible?
>>
>
> When you say you have Python wrappers, how have you written them? Generally
> PyPy works best with Python interfaces written using CFFI[0].
>
> Cory
>
> [0]: https://cffi.readthedocs.org/en/latest/
>
> _______________________________________________
> pypy-dev mailing list
> pypy-dev at python.org
> https://mail.python.org/mailman/listinfo/pypy-dev