Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder1.news.weretis.net!feeder.erje.net!eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed3.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.023 X-Spam-Evidence: '*H*': 0.95; '*S*': 0.00; 'case.': 0.05; 'function,': 0.07; 'python': 0.09; "object's": 0.09; 'to:addr:comp.lang.python': 0.09; 'cc:addr:python-list': 0.10; 'library': 0.15; 'blocks': 0.16; 'increment': 0.16; 'multiples': 0.16; 'zero,': 0.16; 'wrote:': 0.17; 'circular': 0.17; 'memory': 0.18; 'windows': 0.19; 'written': 0.20; 'info.': 0.22; 'cc:2**0': 0.23; "i've": 0.23; 'cc:no real name:2**0': 0.24; 'cc:addr:python.org': 0.25; 'header:In-Reply-To:1': 0.25; 'header :User-Agent:1': 0.26; 'used,': 0.27; 'question': 0.27; "doesn't": 0.28; 'objects': 0.29; "i'm": 0.29; 'that.': 0.30; 'usually': 0.30; 'lists': 0.31; 'running': 0.32; 'certain': 0.33; 'goes': 0.33; 'affects': 0.33; 'received:google.com': 0.34; 'thanks': 0.34; 'said,': 0.35; 'pm,': 0.35; "won't": 0.35; 'but': 0.36; 'depends': 0.36; 'does': 0.37; 'being': 0.37; 'subject:: ': 0.38; 'some': 0.38; 'release': 0.39; 'where': 0.40; 'free': 0.61; 'back': 0.62; 'necessarily': 0.63; 'different': 0.63; 'times': 0.63; 'here': 0.65; 'gave': 0.65; 'results': 0.65; 'taking': 0.65; 'detail.': 0.65; '2013': 0.84; 'situations,': 0.84; 'verifying': 0.84; 'angel': 0.93 X-Received: by 10.50.6.135 with SMTP id b7mr687249iga.9.1363755103152; Tue, 19 Mar 2013 21:51:43 -0700 (PDT) Newsgroups: comp.lang.python Date: Tue, 19 Mar 2013 21:51:42 -0700 (PDT) In-Reply-To: Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=72.163.216.217; posting-account=tKULhwoAAADGQa_90ngAqNBJ-1rg4uyR References: <76cc4613-8086-4b36-a8bd-8ad0f21a19e0@googlegroups.com> User-Agent: G2/1.0 X-Google-Web-Client: true X-Google-IP: 72.163.216.217 MIME-Version: 1.0 Subject: Re: Wierd behavior of gc.collect From: Bodhi To: comp.lang.python@googlegroups.com Content-Type: text/plain; charset=ISO-8859-1 Cc: python-list@python.org X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Message-ID: Lines: 50 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1363755746 news.xs4all.nl 6968 [2001:888:2000:d::a6]:34375 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:41566 Thanks for the info. I now suspect that the free lists are taking up the memory which won't be released unless we do a collect. I'm verifying that. On Tuesday, March 19, 2013 10:43:11 PM UTC+5:30, Dave Angel wrote: > On 03/19/2013 12:36 PM, Bodhi wrote: > > > I know this, but my question is what does gc.collect do which results in the c library to free memory? Usually it is because of unreferenced objects in a cycle or something, but here that doesn't seem to be the case. > > > > > > > As I said, python calls the C free() function, whether it's when an > > object's ref-count goes to zero, or whether it's during a gc call, where > > circular refs are freed. > > > > But free() does not necessarily release the memory to the OS. And the > > times it does depends on which C library is being used, and what OS it's > > running on. > > > > If the freed memory affects top in some situations, it's a C library > > detail. I've written a replacement C allocator in the past for Windows > > that used a different scheme for blocks over a certain threshold, and > > when those blocks were freed, it gave them back to the OS. But such > > blocks were multiples of 64k, which was the increment for VirtualAlloc. > > > > > > > > > > -- > > DaveA