From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Mattias =?UTF-8?Q?Engdeg=C3=A5rd?= Newsgroups: gmane.emacs.bugs Subject: bug#42490: Emacs is very slow when navigating into a specific C++ file Date: Fri, 24 Jul 2020 18:46:45 +0200 Message-ID: <8E02A060-9CF0-4B1F-A780-4F51336291FA@acm.org> References: <11f564eb-74f1-980b-53e3-2de64abe62e0@algosyn.com> Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.15\)) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="27120"; mail-complaints-to="usenet@ciao.gmane.io" Cc: Alan Mackenzie , 42490@debbugs.gnu.org To: Olivier Scalbert Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Fri Jul 24 18:47:59 2020 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 1jz0rW-0006wD-KN for geb-bug-gnu-emacs@m.gmane-mx.org; Fri, 24 Jul 2020 18:47:58 +0200 Original-Received: from localhost ([::1]:37500 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jz0rV-0003lK-LS for geb-bug-gnu-emacs@m.gmane-mx.org; Fri, 24 Jul 2020 12:47:57 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:57030) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jz0qc-0001x0-Ku for bug-gnu-emacs@gnu.org; Fri, 24 Jul 2020 12:47:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:37106) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jz0qc-00039y-BR for bug-gnu-emacs@gnu.org; Fri, 24 Jul 2020 12:47:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1jz0qc-0000jq-AF for bug-gnu-emacs@gnu.org; Fri, 24 Jul 2020 12:47:02 -0400 X-Loop: help-debbugs@gnu.org In-Reply-To: <11f564eb-74f1-980b-53e3-2de64abe62e0@algosyn.com> Resent-From: Mattias =?UTF-8?Q?Engdeg=C3=A5rd?= Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Fri, 24 Jul 2020 16:47:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 42490 X-GNU-PR-Package: emacs Original-Received: via spool by 42490-submit@debbugs.gnu.org id=B42490.15956092202829 (code B ref 42490); Fri, 24 Jul 2020 16:47:02 +0000 Original-Received: (at 42490) by debbugs.gnu.org; 24 Jul 2020 16:47:00 +0000 Original-Received: from localhost ([127.0.0.1]:48652 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jz0qZ-0000jZ-Mp for submit@debbugs.gnu.org; Fri, 24 Jul 2020 12:46:59 -0400 Original-Received: from mail157c50.megamailservers.eu ([91.136.10.167]:34384 helo=mail51c50.megamailservers.eu) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jz0qY-0000jR-4R for 42490@debbugs.gnu.org; Fri, 24 Jul 2020 12:46:59 -0400 X-Authenticated-User: mattiase@bredband.net DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=megamailservers.eu; s=maildub; t=1595609210; bh=Zo/uolf6gQ3e9yV/yOliLMfMWFIt062vr+qtTOfOQQc=; h=From:Subject:Date:Cc:To:From; b=AlVyzogoxNmBHbB2o0ciJImZjpW7bByqeEBddmVwT8qmLKgD2u2dLKRO68olChCvs AjRwHVxTkDyjgCP08yeNZSWwPE1rf7aBSbKMblBEarNMNWmzR4mNDdmwbZ0DhhuDAE AxEE+7Y/gAZrBioFWYmwLGot3uqagEH+KUPOwcfQ= Feedback-ID: mattiase@acm.or Original-Received: from stanniol.lan (c-4e4ae655.032-75-73746f71.bbcust.telenor.se [85.230.74.78]) (authenticated bits=0) by mail51c50.megamailservers.eu (8.14.9/8.13.1) with ESMTP id 06OGkjYC001989; Fri, 24 Jul 2020 16:46:48 +0000 X-Mailer: Apple Mail (2.3445.104.15) X-CTCH-RefID: str=0001.0A782F26.5F1B107A.0001:SCFSTAT68638221, ss=1, re=-4.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0 X-CTCH-VOD: Unknown X-CTCH-Spam: Unknown X-CTCH-Score: -4.000 X-CTCH-Flags: 0 X-CTCH-ScoreCust: 0.000 X-CSC: 0 X-CHA: v=2.3 cv=MOMeZ/Rl c=1 sm=1 tr=0 a=klNLuyVZdLUgl+K5Uafb2A==:117 a=klNLuyVZdLUgl+K5Uafb2A==:17 a=kj9zAlcOel0A:10 a=M51BFTxLslgA:10 a=yeK0Hb666i2x0e7VDMQA:9 a=CjuIK1q_8ugA:10 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:183497 Archived-At: Hello Olivier, Thanks for the report! Could you try Emacs 27 (or git master), building = from source if necessary? Those versions should be slightly faster, = although the response time is probably well below acceptable. If we distill the essentials of your file to some sort of benchmark, we = might end up with: (with-temp-buffer (c++-mode) (dotimes (_ 1000) (insert "OP(ed,b0) { ldir(); } /* LDIR */\n")) (garbage-collect) (let ((t0 (current-time))) (font-lock-ensure (point-min) (point-max)) (time-to-seconds (time-since t0)))) Emacs 26.3 runs it in 11.9 s on this old lappy, but Emacs 27 does it in = 3.3 s. This is a clear improvement but we should be able to do better. = Alan may have a feeling for where the cycles are spent.