[pypy-dev] Playing with PyPy and Django

[Maciej Fijalkowski]

I don't know :-( not sure if fixing those issues one by one is the way
to go, it's not like *this* particular code is a problem, it's the
culture that breeds those sort of things

On Sun, Feb 8, 2015 at 2:09 PM, Omer Katz <omer.drow at gmail.com> wrote:
> Isn't there anything we can do about it?
> We can open issues at the Django issue tracker if some code slows down
> execution in PyPy.
>
> 2015-02-08 12:17 GMT+02:00 Maciej Fijalkowski <fijall at gmail.com>:
>>
>> Hi Tin
>>
>> I have a bit sad news for you, but essentially from what I looked at
>> profling, the answer seems to be "don't use django, it has not been
>> written with performance in mind". For example here (which features in
>> django admin quite prominently, some stuff calls lazy() at each call):
>>
>> https://github.com/django/django/blob/master/django/utils/functional.py#L48
>>
>> What does it, per call that pypy does not like:
>>
>> * redefines classes
>>
>> * walks the class __mro__ and defines tons of new methods
>>
>> * proxies everything through a not so efficietn mechanisms
>>
>> Those things quite defy the purpose of the JIT - you're making tons of
>> very dynamic things that pypy generally assumes is "static enough", if
>> you wanted to do the same thing in C++, you would need to call gcc
>> with each request, that would not be so much fun.
>>
>> If you really care about performance, consider swapping your web
>> framework to something more performance-oriented where JIT compilation
>> can help.
>>
>> As a side note, we (me and my company, not to be confused with PyPy
>> open source project) do offer looking at proprietary code for
>> benchmarking purposes as a commercial service, look at
>> baroquesoftware.com
>>
>> Cheers,
>> fijal
>>
>>
>>
>> On Sat, Feb 7, 2015 at 1:12 AM, Tin Tvrtković <tinchester at gmail.com>
>> wrote:
>> > Hello, PyPy folks!
>> >
>> > While trying to speed up one of my Django sites, I noticed a new version
>> > of
>> > PyPy
>> > had just been released. So I grabbed a fresh download of PyPy 3 (since
>> > this
>> > is
>> > a Python 3 codebase) and tried taking it out for a spin.
>> >
>> > However, as far as I can see, whatever I try PyPy is consistently slower
>> > than
>> > CPython for this.
>> >
>> > Since this is a proprietary site, I've basically ripped out all the code
>> > except
>> > my settings.py and my requirements; and am benchmarking the Django admin
>> > index.
>> > The results are about the same.
>> >
>> > I've set up a small repo that can be used to reproduce the environment:
>> > https://github.com/Tinche/PyPy-Django-Playground. There's additional
>> > info in
>> > the README there.
>> >
>> > These tests have been carried out on Ubuntu Trusty, 64-bit. CPython 3 is
>> > the
>> > system Python, 3.4. PyPy has been downloaded from the official site and
>> > unzipped.
>> >
>> > So what I basically do is set up an admin session, and use the Django
>> > main
>> > admin
>> > page. 200 warmup requests, then 100 benchmarked requests, look at the
>> > mean
>> > request time.
>> >
>> > Some results:
>> >
>> > Django's runserver, DEBUG mode:
>> >
>> > PyPy3            485.389 [ms]
>> > CPython 3.4      105.777 [ms]
>> >
>> > Django's runserver, no debug:
>> >
>> > PyPy3             44.661 [ms]
>> > CPython 3.4       18.697 [ms]
>> >
>> > Gunicorn, 1 worker, no debug:
>> >
>> > PyPy3             28.615 [ms]
>> > CPython 3.4       13.532 [ms]
>> >
>> > I don't exactly claim to be an expert on benchmarking, but assuming my
>> > site
>> > is similar to the Django admin, CPython's gonna be giving me better
>> > performance.
>> > Also the debug runserver performance is kinda worrying. Nobody's going
>> > to be
>> > running this in production, but it makes development a little slower and
>> > more
>> > annoying than it should be.
>> >
>> > Is there anything to make PyPy more competitive in these kinds of
>> > scenarios?
>> >
>> > Kind regards,
>> > Tin
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