Bug 698125

Summary: Memory leak in get_active_devices() and get_interfaces_info()
Product: Red Hat Enterprise Linux 6 Reporter: Petr Šplíchal <psplicha>
Component: python-ethtoolAssignee: Dave Malcolm <dmalcolm>
Status: CLOSED ERRATA QA Contact: Branislav Náter <bnater>
Severity: medium Docs Contact:
Priority: medium    
Version: 6.1CC: bnater, davids, ohudlick
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: python-ethtool-0.6-2.el6 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
: 712870 (view as bug list) Environment:
Last Closed: 2013-02-21 10:48:05 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 712870    

Description Petr Šplíchal 2011-04-20 09:15:32 UTC 
Description of problem:

While unit-testing the python-ethtool using TC#81755 I've observed
an increased memory usage when functions get_active_devices() and
get_interfaces_info() are called repeatedly (see bug 680559). The
memory usage can be checked by the following script:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

#!/usr/bin/python

import ethtool
import subprocess, os

max = 1000000

def memory():
    """ Get current memory usage in MB """
    command = "ps --no-header -o rss -p %s" % os.getpid()
    p = subprocess.Popen(command.split(), stdout=subprocess.PIPE)
    stdout, stderr = p.communicate()
    return int(stdout) / 1024

def measure(fun, arg):
    """ Run given function on give arg max times """
    start = memory()
    print "\n%s on %s" % (fun, arg)
    for i in range(max + 1):
        result = fun(arg)
        if i % (max / 10) == 0:
            print "%s %% ... %s MB" %
                    (str(100 * i / max).rjust(3), str(memory()).rjust(3))
    print "Memory increase: %s MB" % (memory() - start)

measure(ethtool.get_active_devices, None)
measure(ethtool.get_interfaces_info, 'eth0')
measure(ethtool.get_interfaces_info, 'bad interface name')
measure(os.listdir, '/')

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Which on python-ethtool-0.3-5.1.el6.x86_64 gives:

<built-in function get_active_devices> on None
  0 % ...  36 MB
 10 % ...  46 MB
 20 % ...  56 MB
 30 % ...  65 MB
 40 % ...  75 MB
 50 % ...  84 MB
 60 % ...  94 MB
 70 % ... 104 MB
 80 % ... 113 MB
 90 % ... 123 MB
100 % ... 132 MB
Memory increase: 120 MB

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

And on the latest python-ethtool-0.6-1.el6.x86_64 gives:

<built-in function get_active_devices> on None
  0 % ...  36 MB
 10 % ...  46 MB
 20 % ...  55 MB
 30 % ...  65 MB
 40 % ...  74 MB
 50 % ...  84 MB
 60 % ...  93 MB
 70 % ... 103 MB
 80 % ... 112 MB
 90 % ... 121 MB
100 % ... 131 MB
Memory increase: 118 MB

<built-in function get_interfaces_info> on eth0
  0 % ... 131 MB
 10 % ... 156 MB
 20 % ... 181 MB
 30 % ... 205 MB
 40 % ... 230 MB
 50 % ... 255 MB
 60 % ... 280 MB
 70 % ... 305 MB
 80 % ... 329 MB
 90 % ... 354 MB
100 % ... 379 MB
Memory increase: 256 MB

<built-in function get_interfaces_info> on bad interface name
  0 % ... 379 MB
 10 % ... 404 MB
 20 % ... 429 MB
 30 % ... 453 MB
 40 % ... 478 MB
 50 % ... 503 MB
 60 % ... 528 MB
 70 % ... 553 MB
 80 % ... 577 MB
 90 % ... 602 MB
100 % ... 627 MB
Memory increase: 248 MB

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

So this is not a regression. However it seems there is some memory
issue which causes memory to constantly grow and which should be
investigated.
Comment 1 Petr Šplíchal 2011-04-20 09:24:18 UTC 
Memory check script once more, this time without syntax error ;-)

#!/usr/bin/python

import ethtool
import subprocess, os

max = 1000000

def memory():
    """ Get current memory usage in MB """
    command = "ps --no-header -o rss -p %s" % os.getpid()
    p = subprocess.Popen(command.split(), stdout=subprocess.PIPE)
    stdout, stderr = p.communicate()
    return int(stdout) / 1024

def measure(fun, arg):
    """ Run given function on give arg max times """
    start = memory()
    print "\n%s on %s" % (fun, arg)
    for i in range(max + 1):
        result = fun(arg)
        if i % (max / 10) == 0:
            print "%s %% ... %s MB" % \
                    (str(100 * i / max).rjust(3), str(memory()).rjust(3))
    print "Memory increase: %s MB" % (memory() - start)

measure(ethtool.get_active_devices, None)
measure(ethtool.get_interfaces_info, 'eth0')
measure(ethtool.get_interfaces_info, 'bad interface name')
measure(os.listdir, '/')
Comment 2 David Sommerseth 2011-04-20 09:28:46 UTC 
This should be fixed in upstream commit abc7f912f66d41dd734a10900429d4cad9377da5.

http://fedorapeople.org/gitweb?p=dsommers/public_git/python-ethtool.git;a=commitdiff;h=abc7f912f66d41dd734a10900429d4cad9377da5

This is fix is also included in the python-ethtool-0.7 release.

$ rpm -q python-ethtool
python-ethtool-0.7-2.fc14.x86_64
$ python -c "import ethtool ; print ethtool.version"
python-ethtool v0.7
$ python python-ethtool-memleak-test.py 

<built-in function get_active_devices> on None
  0 % ...  37 MB
 10 % ...  37 MB
 20 % ...  37 MB
 30 % ...  37 MB
 40 % ...  37 MB
 50 % ...  37 MB
 60 % ...  37 MB
 70 % ...  37 MB
 80 % ...  37 MB
 90 % ...  37 MB
100 % ...  37 MB
Memory increase: 23 MB

<built-in function get_interfaces_info> on eth0
  0 % ...  37 MB
 10 % ...  37 MB
 20 % ...  37 MB
 30 % ...  37 MB
 40 % ...  37 MB
 50 % ...  37 MB
 60 % ...  37 MB
 70 % ...  37 MB
 80 % ...  37 MB
 90 % ...  37 MB
100 % ...  37 MB
Memory increase: 8 MB

<built-in function get_interfaces_info> on bad interface name
  0 % ...  37 MB
 10 % ...  37 MB
 20 % ...  37 MB
 30 % ...  37 MB
 40 % ...  37 MB
 50 % ...  37 MB
 60 % ...  37 MB
 70 % ...  37 MB
 80 % ...  37 MB
 90 % ...  37 MB
100 % ...  37 MB
Memory increase: 0 MB

<built-in function listdir> on /
  0 % ...  37 MB
 10 % ...  37 MB
 20 % ...  37 MB
 30 % ...  37 MB
 40 % ...  37 MB
 50 % ...  37 MB
 60 % ...  37 MB
 70 % ...  37 MB
 80 % ...  37 MB
 90 % ...  37 MB
100 % ...  37 MB
Memory increase: 0 MB
Comment 3 David Sommerseth 2011-04-20 09:55:07 UTC 
Results from running the memleak check script via valgrind:

$ valgrind --leak-check=full python python-ethtool-memleak-test.py
[...snip...]
==8434== LEAK SUMMARY:
==8434==    definitely lost: 0 bytes in 0 blocks
==8434==    indirectly lost: 0 bytes in 0 blocks
==8434==      possibly lost: 971,380 bytes in 6,009 blocks
==8434==    still reachable: 131,706 bytes in 3,055 blocks
==8434==         suppressed: 0 bytes in 0 blocks
Comment 4 Dave Malcolm 2011-04-20 17:17:56 UTC 
From my reading of comment #0, the rate of the leak is approximately:

  118MB over a million calls to ethtool.get_active_devices(None)
  256MB over a million calls to ethtool.get_interfaces_info('eth0')

(and these "MB" are the 1024*1024 version of the unit)

i.e. 

  leaking about 124 bytes per call to ethtool.get_active_devices(None)
  leaking about 268 bytes per call to ethtool.get_interfaces_info('eth0')

The precise amount leaked is dependent on the precise arguments to the function.
Comment 5 RHEL Program Management 2011-07-06 01:15:30 UTC 
This request was evaluated by Red Hat Product Management for
inclusion in the current release of Red Hat Enterprise Linux.
Because the affected component is not scheduled to be updated
in the current release, Red Hat is unfortunately unable to
address this request at this time. Red Hat invites you to
ask your support representative to propose this request, if
appropriate and relevant, in the next release of Red Hat
Enterprise Linux. If you would like it considered as an
exception in the current release, please ask your support
representative.
Comment 9 Suzanne Logcher 2012-02-14 23:08:42 UTC 
This request was evaluated by Red Hat Product Management for
inclusion in the current release of Red Hat Enterprise Linux.
Because the affected component is not scheduled to be updated
in the current release, Red Hat is unfortunately unable to
address this request at this time. Red Hat invites you to
ask your support representative to propose this request, if
appropriate and relevant, in the next release of Red Hat
Enterprise Linux. If you would like it considered as an
exception in the current release, please ask your support
representative.
Comment 12 RHEL Program Management 2012-07-10 06:52:58 UTC 
This request was not resolved in time for the current release.
Red Hat invites you to ask your support representative to
propose this request, if still desired, for consideration in
the next release of Red Hat Enterprise Linux.
Comment 13 RHEL Program Management 2012-07-11 01:58:12 UTC 
This request was erroneously removed from consideration in Red Hat Enterprise Linux 6.4, which is currently under development.  This request will be evaluated for inclusion in Red Hat Enterprise Linux 6.4.
Comment 18 errata-xmlrpc 2013-02-21 10:48:05 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2013-0454.html