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: Tue, 27 Dec 2016 09:21:46 +0200 Message-ID: <83lgv1x2et.fsf@gnu.org> References: <83vau6wi7r.fsf@gnu.org> <83tw9qwh4z.fsf@gnu.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: blaine.gmane.org X-Trace: blaine.gmane.org 1482823399 25516 195.159.176.226 (27 Dec 2016 07:23:19 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 27 Dec 2016 07:23:19 +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 Tue Dec 27 08:23:15 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 1cLm6K-0005ku-I6 for geb-bug-gnu-emacs@m.gmane.org; Tue, 27 Dec 2016 08:23:12 +0100 Original-Received: from localhost ([::1]:53049 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cLm6N-0007Rg-II for geb-bug-gnu-emacs@m.gmane.org; Tue, 27 Dec 2016 02:23:17 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:39513) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cLm6F-0007RU-PW for bug-gnu-emacs@gnu.org; Tue, 27 Dec 2016 02:23:08 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cLm6A-0008Go-S5 for bug-gnu-emacs@gnu.org; Tue, 27 Dec 2016 02:23:07 -0500 Original-Received: from debbugs.gnu.org ([208.118.235.43]:40857) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cLm6A-0008Gk-On for bug-gnu-emacs@gnu.org; Tue, 27 Dec 2016 02:23:02 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1cLm6A-0005qc-Fp for bug-gnu-emacs@gnu.org; Tue, 27 Dec 2016 02:23:02 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Tue, 27 Dec 2016 07:23:02 +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=B25279.148282332922397 (code B ref 25279); Tue, 27 Dec 2016 07:23:02 +0000 Original-Received: (at 25279) by debbugs.gnu.org; 27 Dec 2016 07:22:09 +0000 Original-Received: from localhost ([127.0.0.1]:56256 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cLm5J-0005pB-EZ for submit@debbugs.gnu.org; Tue, 27 Dec 2016 02:22:09 -0500 Original-Received: from eggs.gnu.org ([208.118.235.92]:48272) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cLm5H-0005oy-Nj for 25279@debbugs.gnu.org; Tue, 27 Dec 2016 02:22:07 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cLm57-0007qu-M5 for 25279@debbugs.gnu.org; Tue, 27 Dec 2016 02:22:02 -0500 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:49400) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cLm57-0007qq-Iz; Tue, 27 Dec 2016 02:21:57 -0500 Original-Received: from 84.94.185.246.cable.012.net.il ([84.94.185.246]:1643 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1cLm56-0006EW-RF; Tue, 27 Dec 2016 02:21:57 -0500 In-reply-to: (message from Richard Copley on Mon, 26 Dec 2016 21:21:57 +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:127482 Archived-At: > From: Richard Copley > Date: Mon, 26 Dec 2016 21:21:57 +0000 > Cc: 25279@debbugs.gnu.org > > > A crash shouldn't happen in any case, so if you can show a recipe and > > a backtrace, maybe this could be fixed. > > > > Thanks. > > Reproducing the slowness and high CPU consumption is easy. > > The "crash" I referred to is probably better termed a "hang" (as > far as I can see an indefinite one), sorry. I don't know a simple > recipe, but if you use Emacs in this state for long enough, it > usually hangs eventually. Is it a hang, or just some long and very busy loop? E.g., if you set garbage-collection-messages to a non-nil value, do you see periodic announcements of GC during the "hang"? And if you go for a coffee, does Emacs eventually recover and starts responding again? What if you type M-< or M-> to force the problematic characters out of the displayed portion of the buffer -- does Emacs recover then? > Recipe: > Uninstall Symbola (but perhaps other font changes are required). It isn't easy to uninstall fonts from a running system, because they are usually in use by some application. So reproducing this will be hard for me, as I have Symbola installed everywhere. I will try to find such a system, but no promises. > Below are C call stacks obtained from a hung emacs process > by attaching gdb to it. Is it possible for you to try to figure out what is the looping stack frame, by following the advice in etc/DEBUG, under "If the symptom of the bug is that Emacs fails to respond"? > Possibly a clue: > While I had the hung emacs process stopped in GDB I started a > new Emacs process to edit this email and the new Emacs was > also horribly slow! When I killed the process in the debugger, > the new Emacs recovered to normal speed. Attaching a debugger to Emacs built from the master branch causes such problems due to the low-level keyboard hook in Emacs. (We avoid that problem when Emacs is started from GDB to begin with.) So I don't think this is relevant to the issue at hand. Thanks.