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: bug-reference-prog-mode slows down CC Mode's scrolling by ~7% Date: Mon, 6 Sep 2021 10:46:48 +0000 Message-ID: References: <837dfwyird.fsf@gnu.org> <835yvgwdxb.fsf@gnu.org> <8335qkwddv.fsf@gnu.org> <83wnnwuxkj.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="12789"; mail-complaints-to="usenet@ciao.gmane.io" Cc: monnier@iro.umontreal.ca, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Sep 06 12:49:22 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 1mNCBl-00031w-2n for ged-emacs-devel@m.gmane-mx.org; Mon, 06 Sep 2021 12:49:21 +0200 Original-Received: from localhost ([::1]:51872 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mNCBj-0002jS-5D for ged-emacs-devel@m.gmane-mx.org; Mon, 06 Sep 2021 06:49:19 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:53820) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mNC9f-0000QR-IO for emacs-devel@gnu.org; Mon, 06 Sep 2021 06:47:13 -0400 Original-Received: from colin.muc.de ([193.149.48.1]:28872 helo=mail.muc.de) by eggs.gnu.org with smtp (Exim 4.90_1) (envelope-from ) id 1mNC9b-0008Oi-D1 for emacs-devel@gnu.org; Mon, 06 Sep 2021 06:47:11 -0400 Original-Received: (qmail 45877 invoked by uid 3782); 6 Sep 2021 10:46:49 -0000 Original-Received: from acm.muc.de (p4fe15c0e.dip0.t-ipconnect.de [79.225.92.14]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Mon, 06 Sep 2021 12:46:48 +0200 Original-Received: (qmail 6722 invoked by uid 1000); 6 Sep 2021 10:46:48 -0000 Content-Disposition: inline In-Reply-To: <83wnnwuxkj.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:274102 Archived-At: Hello, Eli and Stefan. On Sat, Sep 04, 2021 at 19:15:08 +0300, Eli Zaretskii wrote: > > Date: Sat, 4 Sep 2021 16:05:44 +0000 > > Cc: monnier@iro.umontreal.ca, emacs-devel@gnu.org > > From: Alan Mackenzie > > My previous timings were on a Linux console tty. Moving to X, and > > starting Emacs with emacs --no-desktop, I get 34 Lines and 80 columns. > > With my new propose jit-lock code I get the following timings with these > > jit-lock-chunk-sizes: > > (500): 24.5s > > (2000): 18.0s > > (8000): 16.4s > > .. So it would seem, at least in CC Mode, a larger jit-lock-chunk-size is > > advantageous on a default size GUI Emacs, too. > Yes, I guess we should increase the default. I think the optimal size for jit-lock-chunk-size is a little over how much text fits in a window. That way, an entire window can be fontified in a single chunk, minimising overhead. However, much more than that, and the fontification is less JIT, more like fontifying large chunks of a buffer just in case. So, I propose a default value of 2000. Approximately 1700 characters of xdisp.c fit into a default sized GUI window. I think the doc string should say a little more. So, how about: diff --git a/lisp/jit-lock.el b/lisp/jit-lock.el index a1287926eb..4c612a6398 100644 --- a/lisp/jit-lock.el +++ b/lisp/jit-lock.el @@ -44,10 +44,13 @@ jit-lock :version "21.1" :group 'font-lock) -(defcustom jit-lock-chunk-size 500 +(defcustom jit-lock-chunk-size 2000 "Jit-lock fontifies chunks of at most this many characters at a time. -This variable controls both display-time and stealth fontification." +This variable controls both display-time and stealth fontification. + +The optimum value is a little over the typical number of buffer +characters which fit in a window." :type 'integer) > Thanks. -- Alan Mackenzie (Nuremberg, Germany).