From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.devel Subject: Re: cc-mode fontification feels random Date: Fri, 11 Jun 2021 16:11:19 +0000 Message-ID: References: <62e438b5-d27f-1d3c-69c6-11fe29a76d74@dancol.org> <83fsxsdxhu.fsf@gnu.org> <83pmwudgw3.fsf@gnu.org> <83k0n2cjg5.fsf@gnu.org> <83im2lbqmv.fsf@gnu.org> <179f6e4fa40.2816.cc5b3318d7e9908e2c46732289705cb0@dancol.org> <83fsxpbpn9.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="4899"; mail-complaints-to="usenet@ciao.gmane.io" Cc: rudalics@gmx.at, Daniel Colascione , emacs-devel@gnu.org, monnier@iro.umontreal.ca, rms@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Fri Jun 11 18:13:03 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 1lrjmI-0000yt-GH for ged-emacs-devel@m.gmane-mx.org; Fri, 11 Jun 2021 18:13:02 +0200 Original-Received: from localhost ([::1]:38570 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lrjmH-0006GJ-GB for ged-emacs-devel@m.gmane-mx.org; Fri, 11 Jun 2021 12:13:01 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:53468) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lrjkl-0003kD-51 for emacs-devel@gnu.org; Fri, 11 Jun 2021 12:11:27 -0400 Original-Received: from colin.muc.de ([193.149.48.1]:64828 helo=mail.muc.de) by eggs.gnu.org with smtp (Exim 4.90_1) (envelope-from ) id 1lrjki-0001Ak-Jl for emacs-devel@gnu.org; Fri, 11 Jun 2021 12:11:26 -0400 Original-Received: (qmail 99861 invoked by uid 3782); 11 Jun 2021 16:11:20 -0000 Original-Received: from acm.muc.de (p4fe15c6b.dip0.t-ipconnect.de [79.225.92.107]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Fri, 11 Jun 2021 18:11:19 +0200 Original-Received: (qmail 6163 invoked by uid 1000); 11 Jun 2021 16:11:19 -0000 Content-Disposition: inline In-Reply-To: <83fsxpbpn9.fsf@gnu.org> X-Submission-Agent: TMDA/1.3.x (Ph3nix) X-Primary-Address: acm@muc.de Received-SPF: pass client-ip=193.149.48.1; envelope-from=acm@muc.de; helo=mail.muc.de 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_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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:270704 Archived-At: Hello, Eli. On Thu, Jun 10, 2021 at 20:22:50 +0300, Eli Zaretskii wrote: > > From: Daniel Colascione > > Date: Thu, 10 Jun 2021 10:07:52 -0700 > > Cc: rudalics@gmx.at, monnier@iro.umontreal.ca, rms@gnu.org, emacs-devel@gnu.org > > > Then I suggest to set it to 2 by default. > > Performance is reasonable most of the time. > Not IME. I have measured CC Mode's scrolling performance using: (defmacro time-it (&rest forms) "Time the running of a sequence of forms using `float-time'. Call like this: \"M-: (time-it (foo ...) (bar ...) ...)\"." `(let ((start (float-time))) ,@forms (- (float-time) start))) together with M-: (time-it (scroll-up-window) (sit-for 0)) on regions of text which are not yet fontified. My window has 65 lines of buffer text. Starting at the middle of xdisp.c, I see the following timings for the first few scrolls: 0.026s, 0.025s, 0.026s, 0.078s, 0.026s, 0.027s. That is, with the exception of the fourth timing, the scroll operation takes a little over 1/40 second. This is in an Emacs-28 compiled with default optimisation, on a 4 year-old first generation Ryzen machine. For me personally, this scrolling speed, in conjunction with fast-but-imprecise-scrolling, is acceptable. I also accept there are people with slower machines. -- Alan Mackenzie (Nuremberg, Germany).