[Python-Dev] PEP 393 review

[M.-A. Lemburg]

"Martin v. Löwis" wrote:
> tl;dr: PEP-393 reduces the memory usage for strings of a very small
> Django app from 7.4MB to 4.4MB, all other objects taking about 1.9MB.
> 
> Am 26.08.2011 16:55, schrieb Guido van Rossum:
>> It would be nice if someone wrote a test to roughly verify these
>> numbers, e.v. by allocating lots of strings of a certain size and
>> measuring the process size before and after (being careful to adjust
>> for the list or other data structure required to keep those objects
>> alive).
> 
> I have now written a Django application to measure the effect of PEP
> 393, using the debug mode (to find all strings), and sys.getsizeof:
> 
> https://bitbucket.org/t0rsten/pep-393/src/ad02e1b4cad9/pep393utils/djmemprof/count/views.py
> 
> The results for 3.3 and pep-393 are attached.
> 
> The Django app is small in every respect: trivial ORM, very few
> objects (just for the sake of exercising the ORM at all),
> no templating, short strings. The memory snapshot is taken in
> the middle of a request.
> 
> The tests were run on a 64-bit Linux system with 32-bit Py_UNICODE.

For comparison, could you run the test of the unmodified
Python 3.3 on a 16-bit Py_UNICODE version as well ?

Thanks,
-- 
Marc-Andre Lemburg
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