From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: The Emacs master is much slower than the emacs-27 branch. Date: Fri, 04 Dec 2020 21:58:46 +0200 Message-ID: <83360le421.fsf@gnu.org> 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> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="40329"; mail-complaints-to="usenet@ciao.gmane.io" Cc: acm@muc.de, stephen.berman@gmx.net, emacs-devel@gnu.org To: Gregory Heytings Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Fri Dec 04 22:13:54 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 1klIOn-000AOG-2r for ged-emacs-devel@m.gmane-mx.org; Fri, 04 Dec 2020 22:13:53 +0100 Original-Received: from localhost ([::1]:49164 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1klIOm-0002HH-53 for ged-emacs-devel@m.gmane-mx.org; Fri, 04 Dec 2020 16:13:52 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:53764) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1klHER-0006Bj-S1 for emacs-devel@gnu.org; Fri, 04 Dec 2020 14:59:09 -0500 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:57335) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1klHEO-0007Vs-R7; Fri, 04 Dec 2020 14:59:04 -0500 Original-Received: from [176.228.60.248] (port=4731 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1klHEN-0005BM-MX; Fri, 04 Dec 2020 14:59:04 -0500 In-Reply-To: (message from Gregory Heytings on Fri, 04 Dec 2020 19:27:37 +0000) 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:260322 Archived-At: > Date: Fri, 04 Dec 2020 19:27:37 +0000 > From: Gregory Heytings > cc: Stephen Berman , acm@muc.de, emacs-devel@gnu.org > > Indeed with CFLAGS='-Og -g3', on my computer (Debian GNU/Linux, GCC > 10.2.0) with 28.0.50 this benchmark takes 25.2 seconds, whereas with > 27.1.50 it takes 67.6 seconds. > > I bisected this, and the origin of the regression is commit > 365dad197bac5deec9244fd9c189d23c46c99b31, which changes the default to > "use 'static' instead of 'extern inline' [in C headers] because 'static' > typically has better performance for Emacs". With -Og or -O0, the > benchmark takes 67 seconds, with -O1 or above (-O2 is the default) it > takes 25 seconds. Thanks, then I think there''s no issue here, and we can stop wondering about the difference in performance.