This recipe provides a number of functions to get the memory usage of a Python application on Linux.
Python, 43 lines
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Copy to clipboard1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 | import os
_proc_status = '/proc/%d/status' % os.getpid()
_scale = {'kB': 1024.0, 'mB': 1024.0*1024.0,
'KB': 1024.0, 'MB': 1024.0*1024.0}
def _VmB(VmKey):
'''Private.
'''
global _proc_status, _scale
# get pseudo file /proc/<pid>/status
try:
t = open(_proc_status)
v = t.read()
t.close()
except:
return 0.0 # non-Linux?
# get VmKey line e.g. 'VmRSS: 9999 kB\n ...'
i = v.index(VmKey)
v = v[i:].split(None, 3) # whitespace
if len(v) < 3:
return 0.0 # invalid format?
# convert Vm value to bytes
return float(v[1]) * _scale[v[2]]
def memory(since=0.0):
'''Return memory usage in bytes.
'''
return _VmB('VmSize:') - since
def resident(since=0.0):
'''Return resident memory usage in bytes.
'''
return _VmB('VmRSS:') - since
def stacksize(since=0.0):
'''Return stack size in bytes.
'''
return _VmB('VmStk:') - since
|
To find the memory usage in a particular section of code these functions are typically used as follows
<pre> m0 = memory() ... m1 = memory(m0) </pre>
Getting and parsing the /proc//status file is not the most efficient way to determine the memory usage.
This recipe has been tested on RedHat Linux 8.0 with Python 2.3.2.
Tags: sysadmin
RE: memory usage. it's good idea! thank you.
but it can only get the information for current process. in my Application, i want only to get the memory usage for children process(os.popen("children_process") or os.exec("children_process")).
how can i do?
memory usage of child processes. You can get the memory usage of any process by using the proper _process_status string: simply replace os.getpid() with the pid of the process. To get the pid of a spawned process, use the Popen3 class from the standard popen2 module.
For more details, see recipe 6.6 "Capturing the Output and Error Streams from a Unix Shell Command" by Brent Burley on page 227 of the Python Cookbook by O'Reilly, check the documentation of the popen2 module and source code in file .../lib/python.../popen2.py of your Python installation.
i think that the "proper_process_status" can be used only in Linux, it can't be runned in Unix (i.e.Solaris). because the file /proc/pid/sttus is a binary-file.
perhaps the function "resource.getrusage(resource.RUSAGE_CHILDREN)" is a choice too. but I don't konw how use it. :(