Path: csiph.com!eeepc.pasdenom.info!news.pasdenom.info!news.dougwise.org!aioe.org!news.stack.nl!newsfeed.xs4all.nl!newsfeed5.news.xs4all.nl!xs4all!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 0.000 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'emulate': 0.07; "he's": 0.07; 'identical': 0.07; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:80.91.229.12': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'received:lo.gmane.org': 0.09; 'semantics': 0.09; 'subject:removing': 0.09; 'that).': 0.09; 'url:faq': 0.09; 'scripts': 0.09; 'server,': 0.12; 'wrote:': 0.14; 'linux': 0.14; 'creation.': 0.16; 'cygwin': 0.16; 'cygwin,': 0.16; 'kern': 0.16; 'make).': 0.16; 'scenarios': 0.16; 'subject:Idea': 0.16; 'memory': 0.18; 'saying': 0.22; 'stefan': 0.23; 'header:In-Reply-To:1': 0.23; 'perl': 0.24; 'code': 0.25; "isn't": 0.26; 'windows': 0.28; 'project': 0.29; 'received:84': 0.30; 'to:addr:python-list': 0.31; 'considering': 0.31; 'intensive': 0.31; 'header:X-Complaints- To:1': 0.32; 'hours.': 0.32; 'mention': 0.33; 'windows.': 0.33; 'does': 0.33; 'minutes.': 0.34; 'windows,': 0.34; 'pass': 0.34; 'header:User-Agent:1': 0.34; 'received:org': 0.35; 'shell': 0.36; 'used': 0.36; 'less': 0.37; 'data': 0.38; 'entirely': 0.39; 'subject:: ': 0.39; 'header:Mime-Version:1': 0.39; 'to:addr:python.org': 0.40; 'could': 0.40; 'full': 0.61; 'due': 0.69; 'took': 0.69; 'heavy': 0.71; 'here.': 0.71; 'gig': 0.84; 'lifting': 0.91; 'url:api': 0.93 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Stefan Behnel Subject: Re: Idea for removing the GIL... Date: Tue, 08 Feb 2011 18:05:33 +0100 References: <7d3a67ba-b5ff-4b11-95b5-71f041dfc63a@o7g2000prn.googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Gmane-NNTP-Posting-Host: dslb-084-056-035-247.pools.arcor-ip.net User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101208 Lightning/1.0b2 Thunderbird/3.1.7 In-Reply-To: X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 25 NNTP-Posting-Host: 82.94.164.166 X-Trace: 1297185009 news.xs4all.nl 81483 [::ffff:82.94.164.166]:50978 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:55718 Roy Smith, 08.02.2011 17:52: > Robert Kern wrote: > >> Unlike a UNIX fork, CreateProcess() does not have the same copy-on-write >> semantics for initializing the memory of the new process. If you want to pass >> data to the children, the data must be pickled and sent across the process >> boundary. He's not saying that multiprocessing isn't useful at all on >> Windows, just less useful for the scenarios he is considering here. > > Amen, brother! I used to work on a project that had a build system > which was very fork() intensive (lots of little perl and shell scripts > driven by make). A full system build on a linux box took 30-60 minutes. > Building the same code on windows/cygwin took about 12 hours. Identical > hardware (8-core, 16 gig Dell server, or something like that). > > As far as we could tell, it was entirely due to how bad Windows was at > process creation. Unlikely. Since you mention cygwin, it was likely due to the heavy lifting cygwin does in order to emulate fork() on Windows. http://www.cygwin.com/faq/faq-nochunks.html#faq.api.fork Stefan