Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail From: Michael Torrie Newsgroups: comp.lang.python Subject: Re: Python garbage collection: not releasing memory to OS! Date: Fri, 15 Apr 2016 07:59:47 -0600 Lines: 25 Message-ID: References: <215cf2a4-c2fa-41d0-8c49-23b9494234d4@googlegroups.com> <5710F3D3.7010603@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Trace: news.uni-berlin.de NijXXLxh6GjXsSM33riVdA7oFLV21X/2oMD7lZPqF+Gg== Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.001 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'subject:Python': 0.05; 'memory.': 0.05; 'finished.': 0.07; 'lines.': 0.07; 'problem?': 0.07; 'spawn': 0.09; 'python': 0.10; 'itself.': 0.11; 'subject:not': 0.11; 'output': 0.13; '(completely': 0.16; 'correctly,': 0.16; 'from:addr:torriem': 0.16; 'from:name:michael torrie': 0.16; 'received:io': 0.16; 'received:psf.io': 0.16; 'released.': 0.16; 'subprocess': 0.16; 'wrote:': 0.16; 'memory': 0.17; 'config': 0.18; 'python?': 0.18; 'input': 0.18; 'amounts': 0.22; 'file.': 0.22; 'am,': 0.23; 'finished': 0.23; "python's": 0.23; 'tried': 0.24; 'header:In-Reply-To:1': 0.24; 'module': 0.25; 'header:User-Agent:1': 0.26; 'separate': 0.27; 'question': 0.27; 'function': 0.28; 'concern': 0.29; 'code': 0.30; 'task': 0.30; 'checked': 0.31; 'guess': 0.31; 'run': 0.33; 'message- id:@gmail.com': 0.34; 'file': 0.34; 'returning': 0.35; 'skip:* 20': 0.35; 'stopped': 0.35; 'there': 0.36; 'data.': 0.36; 'to:addr :python-list': 0.36; 'subject:: ': 0.37; 'say': 0.37; 'received:org': 0.37; 'why': 0.39; 'received:192': 0.39; 'to:addr:python.org': 0.40; 'your': 0.60; 'email addr:gmail.com': 0.62; 'charset:windows-1252': 0.62; 'is.': 0.63; 'facilities': 0.72; '**is': 0.84; 'rises': 0.84; 'killed': 0.91 X-Virus-Scanned: amavisd-new at torriefamily.org User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.2 In-Reply-To: <215cf2a4-c2fa-41d0-8c49-23b9494234d4@googlegroups.com> X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Mailman-Original-Message-ID: <5710F3D3.7010603@gmail.com> X-Mailman-Original-References: <215cf2a4-c2fa-41d0-8c49-23b9494234d4@googlegroups.com> Xref: csiph.com comp.lang.python:107057 On 04/15/2016 04:25 AM, cshintov@gmail.com wrote: > The input was a 4MB file. Even after returning from the 'fileopen' > function the 4MB memory was not released. I checked htop output while > the loop was running, the resident memory stays at 14MB. So unless > the process is stopped the memory stays with it. I guess the question is, why is this a problem? If there are no leaks, then I confess I don't understand what your concern is. And indeed you say it's not leaking as it never rises above 14 MB. Also there are ways of reading a file without allocating huge amounts of memory. Why not read it in in chunks, or in lines. Take advantage of Python's generator facilities to process your data. > So if the celery worker is not killed after its task is finished it > is going to keep the memory for itself. I know I can use > **max_tasks_per_child** config value to kill the process and spawn a > new one. **Is there any other way to return the memory to OS from a > python process?.** Have you tried using the subprocess module of python? If I understand it correctly, this would allow you to run python code as a subprocess (completely separate process), which would be completely reaped by the OS when it's finished.