From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: "Ludwig, Mark" Newsgroups: gmane.emacs.help Subject: RE: Performance problems (CPU 100%) with NULs in files Date: Thu, 22 Sep 2011 13:00:42 +0000 Message-ID: References: <3BB0836868D54090A9A9930F81EFF891@us.oracle.com> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable X-Trace: dough.gmane.org 1316696466 25512 80.91.229.12 (22 Sep 2011 13:01:06 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Thu, 22 Sep 2011 13:01:06 +0000 (UTC) To: "help-gnu-emacs@gnu.org" Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Thu Sep 22 15:01:02 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 1R6ite-0000HP-0Z for geh-help-gnu-emacs@m.gmane.org; Thu, 22 Sep 2011 15:00:58 +0200 Original-Received: from localhost ([::1]:41492 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R6itb-0001rz-HV for geh-help-gnu-emacs@m.gmane.org; Thu, 22 Sep 2011 09:00:55 -0400 Original-Received: from eggs.gnu.org ([140.186.70.92]:35966) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R6itW-0001ri-P6 for help-gnu-emacs@gnu.org; Thu, 22 Sep 2011 09:00:51 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1R6itQ-000810-AN for help-gnu-emacs@gnu.org; Thu, 22 Sep 2011 09:00:50 -0400 Original-Received: from usslmhub002.ugs.com ([134.244.32.85]:29721 helo=ugs.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R6itQ-00080r-3f for help-gnu-emacs@gnu.org; Thu, 22 Sep 2011 09:00:44 -0400 Original-Received: from USSLMMBX002.net.plm.eds.com (161.134.138.62) by USSLMHUB002.net.plm.eds.com (134.244.32.85) with Microsoft SMTP Server (TLS) id 14.1.323.3; Thu, 22 Sep 2011 08:00:43 -0500 Original-Received: from USSLMMBX003.net.plm.eds.com ([169.254.2.147]) by USSLMMBX002.net.plm.eds.com ([169.254.1.150]) with mapi id 14.01.0323.003; Thu, 22 Sep 2011 08:00:42 -0500 Thread-Topic: Performance problems (CPU 100%) with NULs in files Thread-Index: Acx4opaN4QXNwclhR/W8cESA6FxoywAPQkYgABFiD6A= In-Reply-To: <3BB0836868D54090A9A9930F81EFF891@us.oracle.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [146.122.220.190] X-detected-operating-system: by eggs.gnu.org: Windows 2000 SP2+, XP SP1+ (seldom 98) X-Received-From: 134.244.32.85 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:82293 Archived-At: > From: Drew Adams [mailto:drew.adams@oracle.com] > Subject: RE: Performance problems (CPU 100%) with NULs in files >=20 > > What happens is that as I scroll through the file, when > > the NULs are visible, Emacs gets into some intensive > > processing for a long time (minutes, sometimes!). It > > eventually unwinds and repaints the display, but any > > movement of point sends it into this loop again. I have > > found that M-< or M-> will quickly reposition away from > > the problem (assuming the beginning and/or end of the file > > do not contain NULs). Most other movement operations send > > it into the loop. > > > > I understand about encodings, and have messed around with > > forcing it into us-ascii, but it appears not to be related > > to this CPU consumption problem. Does anyone know how to > > solve this? I'll file a bug report if this is a legitimate bug. > > I'm just concerned that it's a "feature" of some sort, though > > I hope not. >=20 > Are you using the development version of Emacs (aka Emacs 24)? No, I'm still on Emacs 23, but this behavior has been happening since at le= ast Emacs 21, and perhaps longer than that. (I've just never bothered to r= eport it, because it wasn't affecting me very often.) > If so, I have no idea whether this will help or help you find the > problem, but > you might try doing this to see if it makes a difference: >=20 > (setq-default bidi-display-reordering nil) This variable doesn't seem to exist in Emacs 23, which you probably were im= plying. I tried setting it anyway, and it had no effect. (Is it possible = to have undefined/invisible variables that the code uses if they are brough= t into existence?) > Others might have helpful suggestions. In any case, especially if you > have a > reproducible case starting from `emacs -Q' (no init file), I'd suggest > reporting > a bug. Emacs developers will be able to tell you whether there is > really a bug. The problem does reproduce with -Q. It only happens where there are a sign= ificant number of NULs, though. I am narrowing down the range to get to a = minimal test case that shows the problem. > Whatever Emacs version you are using, this sounds like a regression wrt > the > behavior you report with an older version. Hehe. I have no idea what Emacs version did NOT do this, other than being = certain that it did not happen in the TECO-based EMACS in the 1980's.... Cheers, Mark