From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#38407: 27.0.50; infinite loop with display of large file without newlines Date: Thu, 28 Nov 2019 20:53:34 +0200 Message-ID: <83k17jq1ch.fsf@gnu.org> References: <39c498717f8958e7fdc408d4da51d378@webmail.orcon.net.nz> <24031.28277.201123.531348@cochabamba.vanoostrum.org> <83r21sowx1.fsf@gnu.org> <24032.4698.256238.87458@cochabamba.vanoostrum.org> Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="208419"; mail-complaints-to="usenet@blaine.gmane.org" Cc: psainty@orcon.net.nz, 38407@debbugs.gnu.org To: Pieter van Oostrum Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Thu Nov 28 21:31:00 2019 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iaQRI-000s3F-M8 for geb-bug-gnu-emacs@m.gmane.org; Thu, 28 Nov 2019 21:31:00 +0100 Original-Received: from localhost ([::1]:53040 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iaQRG-0006Tq-FN for geb-bug-gnu-emacs@m.gmane.org; Thu, 28 Nov 2019 15:30:58 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:53748) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iaP1T-0006sj-6M for bug-gnu-emacs@gnu.org; Thu, 28 Nov 2019 14:00:19 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iaOvT-0004vB-09 for bug-gnu-emacs@gnu.org; Thu, 28 Nov 2019 13:54:05 -0500 Original-Received: from debbugs.gnu.org ([209.51.188.43]:53156) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1iaOvS-0004uP-Rm for bug-gnu-emacs@gnu.org; Thu, 28 Nov 2019 13:54:02 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1iaOvS-0000gK-RY for bug-gnu-emacs@gnu.org; Thu, 28 Nov 2019 13:54:02 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 28 Nov 2019 18:54:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 38407 X-GNU-PR-Package: emacs Original-Received: via spool by 38407-submit@debbugs.gnu.org id=B38407.15749672202573 (code B ref 38407); Thu, 28 Nov 2019 18:54:02 +0000 Original-Received: (at 38407) by debbugs.gnu.org; 28 Nov 2019 18:53:40 +0000 Original-Received: from localhost ([127.0.0.1]:59126 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iaOv5-0000fQ-Qs for submit@debbugs.gnu.org; Thu, 28 Nov 2019 13:53:40 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:60211) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iaOv4-0000fD-WD for 38407@debbugs.gnu.org; Thu, 28 Nov 2019 13:53:39 -0500 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:47511) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1iaOuu-0002Fx-1U; Thu, 28 Nov 2019 13:53:28 -0500 Original-Received: from [176.228.60.248] (port=4987 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1iaOuq-0002nL-Eh; Thu, 28 Nov 2019 13:53:24 -0500 In-reply-to: <24032.4698.256238.87458@cochabamba.vanoostrum.org> (message from Pieter van Oostrum on Thu, 28 Nov 2019 19:30:50 +0100) 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: 209.51.188.43 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:172619 Archived-At: > Date: Thu, 28 Nov 2019 19:30:50 +0100 > From: Pieter van Oostrum > Cc: psainty@orcon.net.nz, > 38407@debbugs.gnu.org > > In Emacs 26, it is also slow, but the redisplay comes to an end, so I see this as a kind of regression. The timing with Emacs 26 is very similar to that in Emacs 27, except that it doesn't hang at the end. So my impression is that the real difference is when the scrolling reaches the end of the file. That also happens with M-> (end-of-buffer), which hangs indefinitely (or at least a long time that is virtually indistinguishable from indefinitely) in Emacs 27, but it does finish in Emacs 26. I don't think there's any difference in this aspect between Emacs 26 and 27. I see the same problem in both, FWIW, and I definitely didn't wait for hours for redisplay to finish, let alone saw it "hang indefinitely", even in an unoptimized build of Emacs 27 on a very slow machine. In my case it took something like 15 minutes. I don't understand why you see such long times. Of course, I tried this with a different JSON file than you did, so maybe there's something in your file that causes even more slowdown. In any case, try the latest master after setting bidi-inhibit-bpa to non-nil. In my testing, this is as fast as Emacs 23, i.e. no bidi reordering at all, give or take some 10%. And if you want the fastest display possible, use Fundamental mode, not Text.