From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Making font-lock handle long lines better Date: Fri, 10 Feb 2017 18:24:48 +0200 Message-ID: <83wpcy2eun.fsf@gnu.org> References: Reply-To: Eli Zaretskii NNTP-Posting-Host: blaine.gmane.org X-Trace: blaine.gmane.org 1486743936 23727 195.159.176.226 (10 Feb 2017 16:25:36 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Fri, 10 Feb 2017 16:25:36 +0000 (UTC) Cc: emacs-devel@gnu.org To: Ryan B Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri Feb 10 17:25:31 2017 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1ccE0n-0005jn-9Y for ged-emacs-devel@m.gmane.org; Fri, 10 Feb 2017 17:25:29 +0100 Original-Received: from localhost ([::1]:44690 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ccE0s-00060Z-KV for ged-emacs-devel@m.gmane.org; Fri, 10 Feb 2017 11:25:34 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:48631) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ccE05-0005yr-8M for emacs-devel@gnu.org; Fri, 10 Feb 2017 11:24:46 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ccE00-0002jb-9W for emacs-devel@gnu.org; Fri, 10 Feb 2017 11:24:45 -0500 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:47601) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ccE00-0002jX-67; Fri, 10 Feb 2017 11:24:40 -0500 Original-Received: from 84.94.185.246.cable.012.net.il ([84.94.185.246]:4978 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1ccDzz-0007w7-Fx; Fri, 10 Feb 2017 11:24:39 -0500 In-reply-to: (message from Ryan B on Fri, 10 Feb 2017 07:44:15 -0800) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2001:4830:134:3::e X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 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.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:212210 Archived-At: > From: Ryan B > Date: Fri, 10 Feb 2017 07:44:15 -0800 > > hi all! it seems like it's been a known issue for a while that font-lock is slow on very long lines. i've tried lots of > optimizations - jit-lock/lazy-lock, font-lock-maximum-decoration, etc. - but even on modern hardware, > fontifying still hangs my emacs for 5-10s on long lines, e.g. 10k-20k characters, whenever they appear. > > i'm thinking of adding an opt-in line length limit to font-lock-mode, after which it would stop fontifying, evaluating > regexps, etc. within each line. i'd love to hear opinions on whether that makes sense, and whether you might > consider accepting it into trunk. Please file a bug report by sending this information using report-emacs-bug. If you can attach to your report a minimal test case that exhibits the problematic behavior, it will be appreciated. Thanks.