From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19243 invoked by alias); 17 Jul 2003 16:34:44 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 19219 invoked from network); 17 Jul 2003 16:34:43 -0000 Received: from unknown (HELO localhost.redhat.com) (66.30.197.194) by sources.redhat.com with SMTP; 17 Jul 2003 16:34:43 -0000 Received: from redhat.com (localhost [127.0.0.1]) by localhost.redhat.com (Postfix) with ESMTP id 130D02B7F; Thu, 17 Jul 2003 12:34:43 -0400 (EDT) Message-ID: <3F16D022.30209@redhat.com> Date: Thu, 17 Jul 2003 16:34:00 -0000 From: Andrew Cagney User-Agent: Mozilla/5.0 (X11; U; NetBSD macppc; en-US; rv:1.0.2) Gecko/20030223 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Robert Vazan Cc: gdb@sources.redhat.com Subject: Re: Terminally slow (75 seconds) on some steps References: <1057999221.6815.ezmlm@sources.redhat.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2003-07/txt/msg00208.txt.bz2 > I am trying to debug large program and I am observing unusual slowdown. > I don't have any breakpoints, I am just running the app. I measured 75 > seconds of wall clock for single click operation that takes fraction of > second outside debugger. Process time (as viewed by ps) of gdb increased > by 68 seconds. I get realtime reaction with some operations and this > delay with some other operations. When single stepping, it seems that > the more lines must be executed the more time it takes in debugger (but > this is in 1-5 seconds range). > > As if gdb was emulating every instruction. I know this isn't the case. > However, breakpoints cause interrupts, so maybe gdb is being bogged down > by some other interrupts, timer maybe? Given that single step can take > one or more seconds, few timers could quickly accumulate to minute. > > I have also this problem that I cannot run the program twice per > session, so I have to restart gdb and consequently reload symbols. I > have aging snapshot from 1. April 2002. Is this a threaded program on GNU/Linux? 5.3 contained a major performance improvement for threaded debugging. Also, something from April '02 is seriously old. Try either 5.3, or a 6.0 snap (see http://www.gnu.org/software/gdb/download/)