From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 23392 invoked by alias); 1 Oct 2003 06:43:00 -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 23382 invoked from network); 1 Oct 2003 06:43:00 -0000 Received: from unknown (HELO zenia.home) (12.223.225.216) by sources.redhat.com with SMTP; 1 Oct 2003 06:43:00 -0000 Received: by zenia.home (Postfix, from userid 5433) id 8B87A20766; Wed, 1 Oct 2003 01:38:40 -0500 (EST) To: ankit thukral Cc: gdb@sources.redhat.com Subject: Re: about QTro packet (tracepoints) References: <20031001062341.86372.qmail@web60106.mail.yahoo.com> From: Jim Blandy Date: Wed, 01 Oct 2003 06:43:00 -0000 In-Reply-To: <20031001062341.86372.qmail@web60106.mail.yahoo.com> Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-SW-Source: 2003-10/txt/msg00013.txt.bz2 ankit thukral writes: > hi all, > i was reading the packets' format in GDB for > tracepoints (like QTStart,QTinit etc.) and came > across > "QTro" packet format.i learned that this packet > transmits the addresses of all the LOADABLE > READ-ONLY > sections to the remote stub so that the latter can > always entertain a request for data belonging to > these > address ranges,even if this was not specified as a > tracepoint action by the user. > would it not be a better option to let the > remote stub collect this information of it's own > (from > it's own copy of the executable) rather than GDB > transmitting it across the network which definitely > is > more costly in terms of time delay suffered by the > process which becomes all the more costly while > debugging a real-time application? If you're running Linux or something like that on the target, sure. But tracepoints also need to work on systems with no operating system at all, just a stub. In that case, the stub has no idea which sections are read-only and which sections may change. The QTro packet is only sent once, when the trace experiment begins; is it actually a major time sink? How many sections do you have?