From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.help Subject: Re: Performance problems (CPU 100%) with NULs in files Date: Sat, 24 Sep 2011 09:04:15 +0300 Message-ID: <83aa9uqxwg.fsf@gnu.org> References: NNTP-Posting-Host: lo.gmane.org X-Trace: dough.gmane.org 1316844147 32135 80.91.229.12 (24 Sep 2011 06:02:27 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Sat, 24 Sep 2011 06:02:27 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Sat Sep 24 08:02:23 2011 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([140.186.70.17]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1R7LJe-00058k-7c for geh-help-gnu-emacs@m.gmane.org; Sat, 24 Sep 2011 08:02:22 +0200 Original-Received: from localhost ([::1]:59361 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R7LJd-0006tV-H6 for geh-help-gnu-emacs@m.gmane.org; Sat, 24 Sep 2011 02:02:21 -0400 Original-Received: from eggs.gnu.org ([140.186.70.92]:50205) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R7LJY-0006tE-Sx for help-gnu-emacs@gnu.org; Sat, 24 Sep 2011 02:02:17 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1R7LJX-00011S-J4 for help-gnu-emacs@gnu.org; Sat, 24 Sep 2011 02:02:16 -0400 Original-Received: from mtaout20.012.net.il ([80.179.55.166]:32798) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R7LJX-00011K-BN for help-gnu-emacs@gnu.org; Sat, 24 Sep 2011 02:02:15 -0400 Original-Received: from conversion-daemon.a-mtaout20.012.net.il by a-mtaout20.012.net.il (HyperSendmail v2007.08) id <0LS000300IEFES00@a-mtaout20.012.net.il> for help-gnu-emacs@gnu.org; Sat, 24 Sep 2011 09:02:13 +0300 (IDT) Original-Received: from HOME-C4E4A596F7 ([84.228.8.215]) by a-mtaout20.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0LS0003RAJFO0PB0@a-mtaout20.012.net.il> for help-gnu-emacs@gnu.org; Sat, 24 Sep 2011 09:02:13 +0300 (IDT) In-reply-to: X-012-Sender: halo1@inter.net.il X-detected-operating-system: by eggs.gnu.org: Solaris 10 (beta) X-Received-From: 80.179.55.166 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:82325 Archived-At: > From: "Ludwig, Mark" > Date: Sat, 24 Sep 2011 00:20:24 +0000 > > What I have found is that the "problem" is due to a "line" of text being extremely long. In the test file I have, it is ~800,000 characters (bytes). (It came to me with NULs, but I can replace those with any other printable character and get the same result.) Yes, this is a well-known case that causes the current display engine become very slow. IIRC, it has been like that since Emacs 21.1. > OTOH, if you guys really think this is worth asking any developer to fix, I'll file a bug report. I don't need to send any data, because it's easy to reproduce this behavior starting with an empty buffer. Please file a bug report. It is not unreasonable to expect the code to be optimized in some way to cater to such use cases. And thanks for taking your time to investigate this.