From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#30457: 26.0.91; bidi-display-reordering makes navigation around melpa/archive-contents slow Date: Wed, 14 Feb 2018 20:40:10 +0200 Message-ID: <83tvujwh2t.fsf@gnu.org> References: Reply-To: Eli Zaretskii NNTP-Posting-Host: blaine.gmane.org X-Trace: blaine.gmane.org 1518633559 19879 195.159.176.226 (14 Feb 2018 18:39:19 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 14 Feb 2018 18:39:19 +0000 (UTC) Cc: 30457@debbugs.gnu.org To: Aaron Jensen Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Wed Feb 14 19:39:15 2018 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1em1xV-0004Rz-1T for geb-bug-gnu-emacs@m.gmane.org; Wed, 14 Feb 2018 19:39:09 +0100 Original-Received: from localhost ([::1]:48378 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1em1zX-00038U-17 for geb-bug-gnu-emacs@m.gmane.org; Wed, 14 Feb 2018 13:41:15 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:39992) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1em1zN-000377-KL for bug-gnu-emacs@gnu.org; Wed, 14 Feb 2018 13:41:06 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1em1zK-0004m8-3N for bug-gnu-emacs@gnu.org; Wed, 14 Feb 2018 13:41:05 -0500 Original-Received: from debbugs.gnu.org ([208.118.235.43]:35254) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1em1zJ-0004lw-VS for bug-gnu-emacs@gnu.org; Wed, 14 Feb 2018 13:41:02 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1em1zJ-0004Hx-NL for bug-gnu-emacs@gnu.org; Wed, 14 Feb 2018 13:41:01 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Wed, 14 Feb 2018 18:41:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 30457 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 30457-submit@debbugs.gnu.org id=B30457.151863362616433 (code B ref 30457); Wed, 14 Feb 2018 18:41:01 +0000 Original-Received: (at 30457) by debbugs.gnu.org; 14 Feb 2018 18:40:26 +0000 Original-Received: from localhost ([127.0.0.1]:43151 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1em1yk-0004Gz-BU for submit@debbugs.gnu.org; Wed, 14 Feb 2018 13:40:26 -0500 Original-Received: from eggs.gnu.org ([208.118.235.92]:48846) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1em1yj-0004Gm-53 for 30457@debbugs.gnu.org; Wed, 14 Feb 2018 13:40:25 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1em1ya-0004Z5-Oc for 30457@debbugs.gnu.org; Wed, 14 Feb 2018 13:40:19 -0500 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:42351) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1em1ya-0004Yx-Cr; Wed, 14 Feb 2018 13:40:16 -0500 Original-Received: from [176.228.60.248] (port=1322 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1em1yZ-0001uk-Rf; Wed, 14 Feb 2018 13:40:16 -0500 In-reply-to: (message from Aaron Jensen on Wed, 14 Feb 2018 08:49:58 -0800) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 208.118.235.43 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.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.org gmane.emacs.bugs:143283 Archived-At: > From: Aaron Jensen > Date: Wed, 14 Feb 2018 08:49:58 -0800 > > In this thread, Eli asked for a real world repro where > bidi-display-reordering slows down emacs: > https://www.reddit.com/r/emacs/comments/7wezb4/how_can_i_make_line_rendering_faster/ > > I found that today, so I wanted to report it. > > Download: https://melpa.org/packages/archive-contents > > emacs -Q archive-contents > > Press and hold C-n (I have a very fast key repeat rate) > > On my machine, it takes about 13 seconds to get to the bottom of the > window (where it first scrolls, not the bottom of the buffer, I don't > have the patience for that). > > (setq bidi-display-reordering nil) > > Press and hold C-n > > On my machine, it takes about 1 second to get to the bottom of the > window. It's a 870K line with multi-level parentheses. As already mentioned there, the BPA implementation that is part of the bidi reordering makes this sluggish due to the many parentheses in such a long line. (However, it's nowhere near 13 sec on my box. And going several lines in one go, as in "C-u 20 C-n", makes it even faster.) > I hope that this is a compelling enough use-case. I don't believe I have > a use-case for it to be `t` right now, so I'll be setting it to `nil` by > default in my config Beware: the code which is used when bidi-display-reordering is nil is unsupported since Emacs 24, so you are on your own when using it. I urge you to reconsider.