From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Gregory Heytings via "Emacs development discussions." Newsgroups: gmane.emacs.devel Subject: Re: The Emacs master is much slower than the emacs-27 branch. Date: Sat, 05 Dec 2020 12:55:19 +0000 Message-ID: References: <877dpyzg9d.fsf@rub.de> <87czzpsyqn.fsf@gmx.net> <83o8j9eqwx.fsf@gnu.org> <874kl1spe9.fsf@gmx.net> <83blf9em55.fsf@gnu.org> <87zh2tr82r.fsf@gmx.net> <87v9dhr7i5.fsf@gmx.net> <838sadefiw.fsf@gnu.org> <83360le421.fsf@gnu.org> <83y2idcn8q.fsf@gnu.org> <83wnxxcmjr.fsf@gnu.org> <83tut0d7e9.fsf@gnu.org> <8c5fe90c-72ca-a2c3-29d2-1849458bb85a@gmx.at> Reply-To: Gregory Heytings Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=US-ASCII Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="39699"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Alpine 2.22 (NEB 394 2020-01-19) Cc: Eli Zaretskii , acm@muc.de, stephen.berman@gmx.net, emacs-devel@gnu.org To: martin rudalics Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Dec 05 13:56:25 2020 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 1klX6t-000ACI-Dl for ged-emacs-devel@m.gmane-mx.org; Sat, 05 Dec 2020 13:56:23 +0100 Original-Received: from localhost ([::1]:57404 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1klX6s-0006VD-GO for ged-emacs-devel@m.gmane-mx.org; Sat, 05 Dec 2020 07:56:22 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:34626) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1klX6H-000651-4W for emacs-devel@gnu.org; Sat, 05 Dec 2020 07:55:45 -0500 Original-Received: from mx.sdf.org ([205.166.94.24]:53159) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1klX6C-0008AK-8z; Sat, 05 Dec 2020 07:55:44 -0500 Original-Received: from sdf.org (IDENT:ghe@faeroes.freeshell.org [205.166.94.9]) by mx.sdf.org (8.15.2/8.14.5) with ESMTPS id 0B5CtNh7029679 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits) verified NO); Sat, 5 Dec 2020 12:55:23 GMT Original-Received: (from ghe@localhost) by sdf.org (8.15.2/8.12.8/Submit) id 0B5Ctw9S027035; Sat, 5 Dec 2020 12:55:58 GMT In-Reply-To: <8c5fe90c-72ca-a2c3-29d2-1849458bb85a@gmx.at> Received-SPF: pass client-ip=205.166.94.24; envelope-from=ghe@sdf.org; helo=mx.sdf.org X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_PASS=-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:260352 Archived-At: >> I don't know what happens on your computer (what is your >> platform/compiler?) but on mine (Debian GNU/Linux with the latest Linux >> kernel and the latest GCC) the effect on -O0 is almost the same as on >> -Og for this particular benchmark. I just tried again on the emacs-27 >> branch: >> >> -Og: ~67s >> -O0: ~63s >> -O1: ~26s >> -O2: ~18s >> -O3: ~17s > > So when I want to compare Emacs 27 and Emacs 28 benchmarks, -Og builds > are off limits. Now can I use O0 builds or do I have to use O1-O3 > builds exclusively? > The emacs-27 branch since commit 365dad197bac5deec9244fd9c189d23c46c99b31 (Sep 4 2019) is about three times slower (at least on this benchmark, with GCC 10.2, on a 64-bit GNU/Linux) than the master branch since commit b9b32074cecb0e0d20cf527eadacbb0b7f5cced9 (Apr 7 2020) with -Og and -O0. With -O[1-3] it is not. I'd guess that Eli will merge b9b32074cecb0e0d20cf527eadacbb0b7f5cced9 into emacs-27 very soon after the Emacs 27.2 release, and this slowdown will disappear.