From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: David.Kastrup@t-online.de (David Kastrup) Newsgroups: gmane.emacs.devel Subject: Re: Any idea about what makes Emacs slow reading on pipes? Date: 18 May 2003 17:36:15 +0200 Sender: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Message-ID: References: <5x1xyye3y4.fsf@kfs2.cua.dk> <5xznllw0wp.fsf@kfs2.cua.dk> <84of20skuq.fsf@lucy.is.informatik.uni-duisburg.de> <84smrc47ga.fsf@lucy.is.informatik.uni-duisburg.de> Reply-To: dak@gnu.org NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable X-Trace: main.gmane.org 1053272151 12901 80.91.224.249 (18 May 2003 15:35:51 GMT) X-Complaints-To: usenet@main.gmane.org NNTP-Posting-Date: Sun, 18 May 2003 15:35:51 +0000 (UTC) Original-X-From: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Sun May 18 17:35:50 2003 Return-path: Original-Received: from quimby.gnus.org ([80.91.224.244]) by main.gmane.org with esmtp (Exim 3.35 #1 (Debian)) id 19HQCU-0003Lw-00 for ; Sun, 18 May 2003 17:35:50 +0200 Original-Received: from monty-python.gnu.org ([199.232.76.173]) by quimby.gnus.org with esmtp (Exim 3.12 #1 (Debian)) id 19HQLr-00013L-00 for ; Sun, 18 May 2003 17:45:31 +0200 Original-Received: from localhost ([127.0.0.1] helo=monty-python.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.10.13) id 19HQDc-0001Vv-03 for emacs-devel@quimby.gnus.org; Sun, 18 May 2003 11:37:00 -0400 Original-Received: from list by monty-python.gnu.org with tmda-scanned (Exim 4.10.13) id 19HQDJ-0000wM-00 for emacs-devel@gnu.org; Sun, 18 May 2003 11:36:41 -0400 Original-Received: from mail by monty-python.gnu.org with spam-scanned (Exim 4.10.13) id 19HQDD-0000dC-00 for emacs-devel@gnu.org; Sun, 18 May 2003 11:36:38 -0400 Original-Received: from mailout01.sul.t-online.com ([194.25.134.80]) by monty-python.gnu.org with esmtp (Exim 4.10.13) id 19HQD3-0008QY-00 for emacs-devel@gnu.org; Sun, 18 May 2003 11:36:25 -0400 Original-Received: from fwd00.sul.t-online.de by mailout01.sul.t-online.com with smtp id 19HQD2-0008O1-0A; Sun, 18 May 2003 17:36:24 +0200 Original-Received: from localhost.localdomain (520018396234-0001@[62.226.12.133]) by fwd00.sul.t-online.com with esmtp id 19HQCv-0lDSfQC; Sun, 18 May 2003 17:36:17 +0200 Original-Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by localhost.localdomain (8.12.8/8.12.8) with ESMTP id h4IFaGZF018585 for ; Sun, 18 May 2003 17:36:16 +0200 Original-Received: (from dak@localhost) by localhost.localdomain (8.12.8/8.12.8/Submit) id h4IFaFmn018581; Sun, 18 May 2003 17:36:15 +0200 Original-To: emacs-devel@gnu.org In-Reply-To: <84smrc47ga.fsf@lucy.is.informatik.uni-duisburg.de> Original-Lines: 35 User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3.50 X-Sender: 520018396234-0001@t-dialin.net X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1b5 Precedence: list List-Id: Emacs development discussions. List-Help: List-Post: List-Subscribe: , List-Archive: List-Unsubscribe: , Errors-To: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Xref: main.gmane.org gmane.emacs.devel:13972 X-Report-Spam: http://spam.gmane.org/gmane.emacs.devel:13972 kai.grossjohann@gmx.net (Kai Gro=DFjohann) writes: > David.Kastrup@t-online.de (David Kastrup) writes: >=20 > > It pretty obviously does. Here is a test: start an xterm. Then run > > > > od -v /dev/zero|dd obs=3D1 > > > > in it. Then, in some other shell window, type > > > > while true;do :; done >=20 > Interestingly enough, I can't observe this effect. At least, the > output scrolls by really fast in both cases, and maybe I just can't > see the difference between two really fast speeds... Interestingly enough, I can't reliably reproduce this effect either. Hilarious. Maybe it has something to do with what xterms I started as background processes (different nicety?). Oh, if I have a block cursor blinking in yet another window, this seems to help. Crazy. > I'm running Linux 2.4.20 on a 2GHz Celeron. I think that means I > don't have Hyperthreading and therefore just one CPU. Perhaps your CPU is to fast. > I've now looked again on another machine (2GHz Mobile Pentium 4, same > kernel), and I can see the leading digits couting, and they count at > the same speed regardless of the while loop. Well, having just half the computing power available at least should not leave you with the same speed, should it? --=20 David Kastrup, Kriemhildstr. 15, 44793 Bochum