From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: Opportunistic GC Date: Mon, 08 Mar 2021 10:50:48 -0500 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="37808"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: eliz@gnu.org, emacs-devel@gnu.org, Andrea Corallo To: Pip Cet Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Mar 08 16:51:59 2021 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lJIAo-0009cs-6L for ged-emacs-devel@m.gmane-mx.org; Mon, 08 Mar 2021 16:51:58 +0100 Original-Received: from localhost ([::1]:58648 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lJIAm-0007pq-Ss for ged-emacs-devel@m.gmane-mx.org; Mon, 08 Mar 2021 10:51:57 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:57944) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lJI9n-0006vc-A4 for emacs-devel@gnu.org; Mon, 08 Mar 2021 10:50:55 -0500 Original-Received: from mailscanner.iro.umontreal.ca ([132.204.25.50]:50806) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lJI9l-0003az-Cs; Mon, 08 Mar 2021 10:50:54 -0500 Original-Received: from pmg3.iro.umontreal.ca (localhost [127.0.0.1]) by pmg3.iro.umontreal.ca (Proxmox) with ESMTP id 64A4344091A; Mon, 8 Mar 2021 10:50:51 -0500 (EST) Original-Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg3.iro.umontreal.ca (Proxmox) with ESMTP id 36B484408A0; Mon, 8 Mar 2021 10:50:50 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1615218650; bh=XpEFaxpJjiOHu9/1aFiBCm5FuWAS+IITQumeZ4ZVLD8=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=lv8ay6n3X356cMd1U0lLpLRw0HldjF6AzvXBN0aE3HyBAgoR/GQ4W89M/YDboOY4m 9r6ef1gfPv7UU3ZGZ8heKMPKCWms8gp/xAtfkiFaVxagmVoddye5bNoXfVjx02Jt0n U71ODH9GDWxVE0QaRG5Vi96/WiSqlnfJIWmFQuT7xpUeKS9b9kQVOomsOq+SzedeVN W86HpRVoy+q8n2swQtNGVTgttnWc58VCEUhO5sOfL2r9a1dFq31wDVDp/3jeIwVWsz S96jO8V0e20FE4wKHDilpyjqQCJJxhqOVZHtKPs759SlXxyWIOleNrIiicCZgBn49A 63Q7zsge14vtg== Original-Received: from alfajor (unknown [216.154.43.249]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id F3BED1203C4; Mon, 8 Mar 2021 10:50:49 -0500 (EST) In-Reply-To: (Pip Cet's message of "Mon, 8 Mar 2021 15:04:32 +0000") Received-SPF: pass client-ip=132.204.25.50; envelope-from=monnier@iro.umontreal.ca; helo=mailscanner.iro.umontreal.ca X-Spam_score_int: -42 X-Spam_score: -4.3 X-Spam_bar: ---- X-Spam_report: (-4.3 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:266198 Archived-At: > I'm not sure. I do know some systems prefer using spawn() to fork() + > exec(), and I always suspected the main reason for that is because > they do not have an efficient fork(). IIRC the reason is that `fork` can be unnecessarily costly if your forked application is large and it just wants to spawn a small /bin/sh process: while `fork` doesn't need to copy the application's pages, it still has to copy its pagetable(!) and it may have to pre-allocate or pre-reserve the pages that it may copy-on-write later. Stefan