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 18:34:54 +0000 Message-ID: References: <83pmwudgw3.fsf@gnu.org> <83k0n2cjg5.fsf@gnu.org> <83im2lbqmv.fsf@gnu.org> <179f6e4fa40.2816.cc5b3318d7e9908e2c46732289705cb0@dancol.org> <83fsxpbpn9.fsf@gnu.org> <83k0n09tkp.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="38462"; mail-complaints-to="usenet@ciao.gmane.io" Cc: rudalics@gmx.at, dancol@dancol.org, 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 20:43:51 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 1lrm8E-0009oL-Kd for ged-emacs-devel@m.gmane-mx.org; Fri, 11 Jun 2021 20:43:50 +0200 Original-Received: from localhost ([::1]:53878 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lrm8D-0006W6-Kq for ged-emacs-devel@m.gmane-mx.org; Fri, 11 Jun 2021 14:43:49 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:51012) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lrlzl-0003O3-FB for emacs-devel@gnu.org; Fri, 11 Jun 2021 14:35:07 -0400 Original-Received: from colin.muc.de ([193.149.48.1]:13214 helo=mail.muc.de) by eggs.gnu.org with smtp (Exim 4.90_1) (envelope-from ) id 1lrlzd-000126-NW for emacs-devel@gnu.org; Fri, 11 Jun 2021 14:35:05 -0400 Original-Received: (qmail 96389 invoked by uid 3782); 11 Jun 2021 18:34:55 -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 20:34:55 +0200 Original-Received: (qmail 6957 invoked by uid 1000); 11 Jun 2021 18:34:54 -0000 Content-Disposition: inline In-Reply-To: <83k0n09tkp.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=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:270713 Archived-At: Hello, Eli. On Fri, Jun 11, 2021 at 20:53:10 +0300, Eli Zaretskii wrote: > > Date: Fri, 11 Jun 2021 16:11:19 +0000 > > Cc: Daniel Colascione , rudalics@gmx.at, > > monnier@iro.umontreal.ca, rms@gnu.org, emacs-devel@gnu.org > > From: Alan Mackenzie > > 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. > I suggest to compare these times with Emacs 23 to see how we > regressed. OK, on emacs-23.3 -Q, otherwise exactly the same circumstances, I get these timings: 0.0093s, 0.0089s, 0.0084s, 0.0144s, 0.0094s, 0.0084s. So the difference is around a factor of 3, perhaps a little more. "Half an order of magnitude" perhaps sums it up best. -- Alan Mackenzie (Nuremberg, Germany).