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: Redisplay slower in Emacs 28 than Emacs 27 Date: Mon, 07 Dec 2020 15:28:18 +0000 Message-ID: References: <877dptiro7.fsf@gnus.org> <87pn3lhcdd.fsf@gnus.org> Reply-To: Gregory Heytings Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="12231"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Alpine 2.22 (NEB 394 2020-01-19) Cc: emacs-devel@gnu.org To: Lars Ingebrigtsen Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Dec 07 16:31:12 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 1kmITn-000352-Oe for ged-emacs-devel@m.gmane-mx.org; Mon, 07 Dec 2020 16:31:11 +0100 Original-Received: from localhost ([::1]:48880 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kmITm-0003p7-Q5 for ged-emacs-devel@m.gmane-mx.org; Mon, 07 Dec 2020 10:31:10 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:41506) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kmIRA-0002NJ-IW for emacs-devel@gnu.org; Mon, 07 Dec 2020 10:28:28 -0500 Original-Received: from mx.sdf.org ([205.166.94.24]:51319) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kmIR8-0005Ky-8F for emacs-devel@gnu.org; Mon, 07 Dec 2020 10:28:28 -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 0B7FSKkB023838 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits) verified NO); Mon, 7 Dec 2020 15:28:20 GMT Original-Received: (from ghe@localhost) by sdf.org (8.15.2/8.12.8/Submit) id 0B7FSvOh021604; Mon, 7 Dec 2020 15:28:57 GMT In-Reply-To: <87pn3lhcdd.fsf@gnus.org> 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:260486 Archived-At: >> I was surprised, too. What I do know is that I observed this 10-15% >> slowdown consistently, on that particular revision, so it cannot be >> accidental. As you see on the graphs, I tested about hundred different >> revisions, each of them ten times. > > I have no explanation for that -- but if you add the "!" back, you > disable the Emacs cache completely. Try it, and load a large image with > > emacs -Q some-megapixel-image.jpg > > and Emacs will become unusable, because it'll re-decode the image for > each update. > I have no explanation either, and I did not write that the solution was to add the "!" back ;-) What is also odd is that the benchmark does not load any image: it loads the "xdisp.c" file and scrolls down until EOF.