From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: Andreas Schwab Newsgroups: gmane.emacs.devel Subject: Re: Any idea about what makes Emacs slow reading on pipes? Date: Fri, 16 May 2003 15:55:33 +0200 Sender: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Message-ID: References: NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Trace: main.gmane.org 1053095222 15124 80.91.224.249 (16 May 2003 14:27:02 GMT) X-Complaints-To: usenet@main.gmane.org NNTP-Posting-Date: Fri, 16 May 2003 14:27:02 +0000 (UTC) Cc: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Fri May 16 16:26:59 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 19Gg4e-0003Pw-00 for ; Fri, 16 May 2003 16:20:40 +0200 Original-Received: from monty-python.gnu.org ([199.232.76.173]) by quimby.gnus.org with esmtp (Exim 3.12 #1 (Debian)) id 19GgD1-00056n-00 for ; Fri, 16 May 2003 16:29:19 +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 19GfzA-0008En-05 for emacs-devel@quimby.gnus.org; Fri, 16 May 2003 10:15:00 -0400 Original-Received: from list by monty-python.gnu.org with tmda-scanned (Exim 4.10.13) id 19Gfy6-0007sD-00 for emacs-devel@gnu.org; Fri, 16 May 2003 10:13:54 -0400 Original-Received: from mail by monty-python.gnu.org with spam-scanned (Exim 4.10.13) id 19Gfxr-0007M3-00 for emacs-devel@gnu.org; Fri, 16 May 2003 10:13:42 -0400 Original-Received: from gnuftp.gnu.org ([199.232.41.6]) by monty-python.gnu.org with esmtp (Exim 4.10.13) id 19Gfws-0005uR-00; Fri, 16 May 2003 10:12:38 -0400 Original-Received: from ns.suse.de ([213.95.15.193] helo=Cantor.suse.de) by gnuftp.gnu.org with esmtp (Exim 4.10.13) id 19Gfgn-0001Db-00; Fri, 16 May 2003 09:56:01 -0400 Original-Received: from Hermes.suse.de (Hermes.suse.de [213.95.15.136]) by Cantor.suse.de (Postfix) with ESMTP id 445D314CAB; Fri, 16 May 2003 15:55:34 +0200 (MEST) Original-To: dak@gnu.org X-Yow: HOW could a GLASS be YELLING?? In-Reply-To: (David Kastrup's message of "16 May 2003 15:08:13 +0200") User-Agent: Gnus/5.1001 (Gnus v5.10.1) Emacs/21.3.50 (gnu/linux) 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:13929 X-Report-Spam: http://spam.gmane.org/gmane.emacs.devel:13929 David.Kastrup@t-online.de (David Kastrup) writes: |> The following exhibits abysmal speed within Emacs: |> |> (let (process-connection-type) (switch-to-buffer (generate-new-buffer |> "*test*"))(erase-buffer)(start-process "test" (current-buffer) "sh" |> "-c" "hexdump -v /dev/zero|dd bs=1 count=100k")(erase-buffer)) |> |> More to the point, things start out dead slow and get faster later. |> It is not the fault of the programs on the sending side: just piping |> into cat >/dev/null instead of Emacs is much much faster. It does |> not seem that setting process-connection-type to nil as above (using |> a pipe instead of a pty) does help worth noting. |> |> The system I see this in is |> GNU Emacs 21.3.50.3 (i686-pc-linux-gnu) |> a RedHat 9 system, but I have seen this in practically every Linux |> system up to now. Is this a Linux-specific problem, or do others see |> this as well? I cannot reproduce that on ppc-suse-linux. I also tried out MacOS X on the same machine, and there the overall speed is much lower, but still mostly constant. Andreas. -- Andreas Schwab, SuSE Labs, schwab@suse.de SuSE Linux AG, Deutschherrnstr. 15-19, D-90429 Nürnberg Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different."