From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: [RFC] Replacing malloc_get_state functionality. Date: Mon, 24 Feb 2014 18:11:35 -0800 Organization: UCLA Computer Science Department Message-ID: <530BFBD7.2040606@cs.ucla.edu> References: <20140220232941.GA2929@domone.podge> <53070258.5090804@cs.ucla.edu> <530BDB13.5040601@dancol.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1393294312 30201 80.91.229.3 (25 Feb 2014 02:11:52 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 25 Feb 2014 02:11:52 +0000 (UTC) Cc: =?UTF-8?B?T25kxZllaiBCw61sa2E=?= To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Feb 25 03:12:00 2014 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1WI7V0-0007Iu-7V for ged-emacs-devel@m.gmane.org; Tue, 25 Feb 2014 03:11:58 +0100 Original-Received: from localhost ([::1]:60654 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WI7Uz-000727-Mb for ged-emacs-devel@m.gmane.org; Mon, 24 Feb 2014 21:11:57 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:48034) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WI7Up-00071z-VC for emacs-devel@gnu.org; Mon, 24 Feb 2014 21:11:55 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WI7Ui-0008H9-MJ for emacs-devel@gnu.org; Mon, 24 Feb 2014 21:11:47 -0500 Original-Received: from smtp.cs.ucla.edu ([131.179.128.62]:41317) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WI7Ui-0008H3-Gp for emacs-devel@gnu.org; Mon, 24 Feb 2014 21:11:40 -0500 Original-Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp.cs.ucla.edu (Postfix) with ESMTP id D2A5239E8014; Mon, 24 Feb 2014 18:11:39 -0800 (PST) X-Virus-Scanned: amavisd-new at smtp.cs.ucla.edu Original-Received: from smtp.cs.ucla.edu ([127.0.0.1]) by localhost (smtp.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ei8tS-WJZltx; Mon, 24 Feb 2014 18:11:39 -0800 (PST) Original-Received: from [192.168.1.9] (pool-108-0-233-62.lsanca.fios.verizon.net [108.0.233.62]) by smtp.cs.ucla.edu (Postfix) with ESMTPSA id 6777F39E8008; Mon, 24 Feb 2014 18:11:39 -0800 (PST) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 In-Reply-To: <530BDB13.5040601@dancol.org> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.x X-Received-From: 131.179.128.62 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 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.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:169854 Archived-At: './configure emacs_cv_var_doug_lea_malloc=no' works for me in the sense that I can do a 'make bootstrap' on Fedora 20 x86-64, and the resulting Emacs works interactively. In this configuration Emacs supplies its own malloc so the performance is not quite as good (text 0.5% larger, data 7.6% larger, 14% more CPU time on my usual benchmark) but I don't observe any bugs. It's possible that there's a bigger problem here; but if so, wouldn't it the same bigger problem exist on non-glibc platforms already? If so, any fix should also work on any future glibc platforms that lack malloc_get_state. More generally, Emacs by itself should not inhibit glibc from making significant malloc performance improvements that would benefit a large set of programs. If Emacs is the main reason these improvements aren't being made, then we should go ahead and make them, as we should be able to tweak Emacs to work well with the resulting system.