From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Gregory Heytings Newsgroups: gmane.emacs.bugs Subject: bug#56682: Fix the long lines font locking related slowdowns Date: Mon, 01 Aug 2022 08:38:19 +0000 Message-ID: References: <837d46mjen.fsf@gnu.org> <8a3eaeef01be5bfaa5ef@heytings.org> <05388e8d8812bfa3695d@heytings.org> <83v8rf5894.fsf@gnu.org> <65cb7c73fd4a999cca00@heytings.org> <8c7321f2f3400a5db9be@heytings.org> <8c7321f2f388e5343475@heytings.org> <6ea376f6-d503-06d8-6d83-50c52b695394@yandex.ru> <8c7321f2f3ac52bfee4b@heytings.org> <8c7321f2f3ec1ef81af9@heytings.org> 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="10558"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 56682@debbugs.gnu.org, Eli Zaretskii , Dmitry Gutov To: Stefan Monnier Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Mon Aug 01 10:39:18 2022 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1oIQxI-0002WE-At for geb-bug-gnu-emacs@m.gmane-mx.org; Mon, 01 Aug 2022 10:39:16 +0200 Original-Received: from localhost ([::1]:38892 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oIQxG-0005Mk-UA for geb-bug-gnu-emacs@m.gmane-mx.org; Mon, 01 Aug 2022 04:39:14 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:58680) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oIQx5-0005Lu-1C for bug-gnu-emacs@gnu.org; Mon, 01 Aug 2022 04:39:03 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:49471) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1oIQx4-0002v6-OE for bug-gnu-emacs@gnu.org; Mon, 01 Aug 2022 04:39:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1oIQx4-0000In-G6 for bug-gnu-emacs@gnu.org; Mon, 01 Aug 2022 04:39:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Gregory Heytings Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Mon, 01 Aug 2022 08:39:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 56682 X-GNU-PR-Package: emacs Original-Received: via spool by 56682-submit@debbugs.gnu.org id=B56682.16593431061096 (code B ref 56682); Mon, 01 Aug 2022 08:39:02 +0000 Original-Received: (at 56682) by debbugs.gnu.org; 1 Aug 2022 08:38:26 +0000 Original-Received: from localhost ([127.0.0.1]:39220 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1oIQwT-0000Hb-J8 for submit@debbugs.gnu.org; Mon, 01 Aug 2022 04:38:26 -0400 Original-Received: from heytings.org ([95.142.160.155]:33418) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1oIQwO-0000HL-Ie for 56682@debbugs.gnu.org; Mon, 01 Aug 2022 04:38:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=heytings.org; s=20220101; t=1659343099; bh=PKX6roBY3dFN+wM/YoZaTkuf6hD+6S07dMwardHkYAE=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References:From; b=lVBRALLJDXYW76MWbWFLS6Vrkw8fvY9OhPM2LFjCVaQq5VCh0t5vPNm+ALHF/GLAC AwZXDKOWVH9Iti2y7y3KIJZqXZEW654qMEYgWcyLSqsNTaseoifmgDbSWxty1dXWV3 OZx52kCXQG6vMNH4NVXHT4cOfyHe5gNd/4ArQvpD2V9zkJ967ug5F46s9BHnJGu2gl eXnFyOGKEjNzO6vPzaHGGcSa71I9v2lEiyBfik1BqniiohLmhKwb7or++kEIDw/J6P 74njcbkHOalPyGDxuB0WCDfBBhg8tDt4p7ptczNyc7lG/x63YyxLZh6XKtyCa14Yap i+TsvxedVxUOQ== In-Reply-To: X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:238394 Archived-At: >>>> That's true, but with such big files, the initial scan is slow. So >>>> the scenario is simple: you open a big enough file, type M->, and >>>> C-p. M-> will be instantaneous, and C-p will take a while, because of >>>> syntax-ppss. >>> >>> Really? I'd expect that `M->` is slow because of `syntax-ppss` >>> (called by font-lock) and then `C-p` is instantaneous. >> >> Yes, really. M-> is fast because syntax-ppss is called inside >> fontification-functions, which are evaluated in a small portion of the >> buffer (with locked narrowing). >> >> [...] >> >> And C-p is slow because post-command-hook is (or rather was) not >> subjected to the same locked narrowing. > > I wonder what `C-p` has to do with `post-command-hook`. > > After all, that same `post-command-hook` is also run after `M->` as > well. > You're right here. Technically it's M-> that is slow. But it's not what the user sees (hence my own confusion): the effect of M-> is immediately visible.