[New-bugs-announce] [issue23324] Python 3.4.2 running slow on Ubuntu 14.10

[Alan Yorinks]

New submission from Alan Yorinks:

Folks,
   I am not trying to waste anyone's time.  If this is not the correct mailing list to get this problem resolved, please point me to the correct one.

   To summarize my problem, if I run the configuration below with python 3.4.2 on Linux, the program reacts to user input (changing a potentiometer) extremely slowly. If I run the exact same code on Windows, there is no slow down. Also, if I run the exact same setup using pypy 3.2.4, there is no slowdown.

   I also tried running the software on pypy 3.2.4 on Linux and there is no slowdown. The only problem I encounter is using Python 3.4.2 on Linux. Python 2.7.8 works without issue on both Linux and Windows.

   The setup to reproduce the problem is not complicated but requires PyMata to be installed on an Arduino Uno or Leonardo attached to the computer.

Prerequisites:
    OS: Ubuntu Linux 14.10.
   Python: 3.4.2
   PyMata 2.02 or can be installed from PyPi
   Requires PySerial 2.7
   Arduino Uno or Leonardo microcontroller with StandardFirmata installed.
  
   Program to be executed: located in the PyMata/examples/digital_analog_io directory. The file is polling_digital_analog_io.py.

How the problem exhibits itself:
   When adjusting the potentiometer to set the intensity level of the LED, the intensity level greatly lags the pot adjustment. On Python 2.7 on Linux and Windows, on Python 3.4.2 on Windows, and on pypy3.2.4 on Linux, there is no lag and the program behaves as expected.

   The only variable is the Linux version of Python 3.4.2, so it is my belief that python 3.4.2 for linux has issues. I will be happy to provide any additional information to help resolve this. Again if this is the wrong mailing list, please point me to the correct one.

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components: Interpreter Core
messages: 234774
nosy: MrYsLab
priority: normal
severity: normal
status: open
title: Python 3.4.2 running slow on Ubuntu 14.10
versions: Python 3.4

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue23324>
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