From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21011 invoked by alias); 22 Feb 2008 16:48:37 -0000 Received: (qmail 21000 invoked by uid 22791); 22 Feb 2008 16:48:37 -0000 X-Spam-Check-By: sourceware.org Received: from smtp-out.google.com (HELO smtp-out.google.com) (216.239.45.13) by sourceware.org (qpsmtpd/0.31) with ESMTP; Fri, 22 Feb 2008 16:48:19 +0000 Received: from zps37.corp.google.com (zps37.corp.google.com [172.25.146.37]) by smtp-out.google.com with ESMTP id m1MGmEYI030931 for ; Fri, 22 Feb 2008 08:48:14 -0800 Received: from wa-out-1112.google.com (wafj32.prod.google.com [10.114.186.32]) by zps37.corp.google.com with ESMTP id m1MGlnXb004075 for ; Fri, 22 Feb 2008 08:48:14 -0800 Received: by wa-out-1112.google.com with SMTP id j32so467027waf.19 for ; Fri, 22 Feb 2008 08:48:14 -0800 (PST) Received: by 10.115.54.1 with SMTP id g1mr162909wak.133.1203698893475; Fri, 22 Feb 2008 08:48:13 -0800 (PST) Received: by 10.115.107.7 with HTTP; Fri, 22 Feb 2008 08:48:13 -0800 (PST) Message-ID: Date: Fri, 22 Feb 2008 17:24:00 -0000 From: "Doug Evans" To: "Michael Snyder" Subject: Re: gdbserver tracepoint support (from Project Ideas page) Cc: gdb@sourceware.org In-Reply-To: <1203623152.19253.193.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <1203552043.19253.186.camel@localhost.localdomain> <1203555989.19253.190.camel@localhost.localdomain> <1203623152.19253.193.camel@localhost.localdomain> X-IsSubscribed: yes Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org X-SW-Source: 2008-02/txt/msg00187.txt.bz2 On Thu, Feb 21, 2008 at 11:45 AM, Michael Snyder wrote: > > A hybrid approach would be way cool (i.e. > > instrumenting the target program so tracepoints didn't stop the > > program even when running natively - this is where remote targets have > > an advantage, the stub is already in the same address space and > > process - but that ups the complexity a wee bit). > > I've always thought that one interesting implementation for > tracepoint data collection would be as a shared library that > the child program could be linked with at runtime -- in the > manner of libsegfault, so that you don't have to change the > child program at all. In that way, it would share address > space and only incur the cost of a signal handler, not a > full context switch (or even a thread context switch). > > Is that something like your thinking? That is one way to implement it, my "way cool" comment had in mind a more efficient implementation (albeit more complex too). I don't have any numbers so I'm not advocating one over the other. btw, is there any existing implementation anywhere for a remote target? Something in libgloss or rda (redhat debug agent?) or some such?