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#25279: 26.0.50; Slowdown/crash on certain characters Date: Mon, 26 Dec 2016 22:49:00 +0200 Message-ID: <83tw9qwh4z.fsf@gnu.org> References: <83vau6wi7r.fsf@gnu.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: blaine.gmane.org X-Trace: blaine.gmane.org 1482785428 10880 195.159.176.226 (26 Dec 2016 20:50:28 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Mon, 26 Dec 2016 20:50:28 +0000 (UTC) Cc: 25279@debbugs.gnu.org To: Richard Copley Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Mon Dec 26 21:50:24 2016 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 1cLcDv-000286-Bi for geb-bug-gnu-emacs@m.gmane.org; Mon, 26 Dec 2016 21:50:23 +0100 Original-Received: from localhost ([::1]:51675 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cLcE0-000314-6Q for geb-bug-gnu-emacs@m.gmane.org; Mon, 26 Dec 2016 15:50:28 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:44528) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cLcDq-000309-EC for bug-gnu-emacs@gnu.org; Mon, 26 Dec 2016 15:50:19 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cLcDl-0007OT-D5 for bug-gnu-emacs@gnu.org; Mon, 26 Dec 2016 15:50:18 -0500 Original-Received: from debbugs.gnu.org ([208.118.235.43]:40644) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cLcDa-0007Il-53 for bug-gnu-emacs@gnu.org; Mon, 26 Dec 2016 15:50:13 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1cLcDZ-0007oQ-Ii for bug-gnu-emacs@gnu.org; Mon, 26 Dec 2016 15:50:01 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Mon, 26 Dec 2016 20:50:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 25279 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 25279-submit@debbugs.gnu.org id=B25279.148278537129985 (code B ref 25279); Mon, 26 Dec 2016 20:50:01 +0000 Original-Received: (at 25279) by debbugs.gnu.org; 26 Dec 2016 20:49:31 +0000 Original-Received: from localhost ([127.0.0.1]:56043 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cLcD5-0007nZ-HG for submit@debbugs.gnu.org; Mon, 26 Dec 2016 15:49:31 -0500 Original-Received: from eggs.gnu.org ([208.118.235.92]:53412) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cLcD4-0007nN-Vu for 25279@debbugs.gnu.org; Mon, 26 Dec 2016 15:49:31 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cLcCu-00074Y-N7 for 25279@debbugs.gnu.org; Mon, 26 Dec 2016 15:49:25 -0500 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:44680) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cLcCu-00074U-Jr; Mon, 26 Dec 2016 15:49:20 -0500 Original-Received: from 84.94.185.246.cable.012.net.il ([84.94.185.246]:1093 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1cLcCt-00059N-Ss; Mon, 26 Dec 2016 15:49:20 -0500 In-reply-to: (message from Richard Copley on Mon, 26 Dec 2016 20:40:42 +0000) 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:127467 Archived-At: > From: Richard Copley > Date: Mon, 26 Dec 2016 20:40:42 +0000 > Cc: 25279@debbugs.gnu.org > > > Because you don't have Symbola installed, I guess. The fonts Emacs > > finds for displaying these characters all have non-Unicode registry > > fields, and that causes Emacs to desperately look for a Unicode font > > each time it needs to display one of these characters. > > OK, thanks, but I don't quite follow, sorry. Unless you're saying there's a > non-desperate mechanism that's usually used but which fails unless a > font with a Unicode registry field is found for the character? When Emacs doesn't find a font with a Unicode registry, it looks in many fonts trying many alternative registries. Each font is tried twice, ones with the Uniscribe back-end, the other one with the GDI back-end. All of that does a lot of consing, so the next GC comes soon, and compacts font caches by deleting all that information. Then the next time redisplay kicks in, it searches all of those fonts again, and again conses a lot, which again causes GC. Etc. etc. > Commendably thorough, but causes the editor to grind to a halt and crash > in some circumstances. A crash shouldn't happen in any case, so if you can show a recipe and a backtrace, maybe this could be fixed. Thanks.