From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 24889 invoked by alias); 3 Mar 2008 16:27:46 -0000 Received: (qmail 24882 invoked by uid 22791); 3 Mar 2008 16:27:45 -0000 X-Spam-Status: No, hits=-2.5 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS,SPF_PASS X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (66.187.233.31) by sourceware.org (qpsmtpd/0.31) with ESMTP; Mon, 03 Mar 2008 16:27:24 +0000 Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id m23GRNQ5032716 for ; Mon, 3 Mar 2008 11:27:23 -0500 Received: from pobox.corp.redhat.com (pobox.corp.redhat.com [10.11.255.20]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id m23GRMDM020464; Mon, 3 Mar 2008 11:27:22 -0500 Received: from opsy.redhat.com (vpn-15-122.rdu.redhat.com [10.11.15.122]) by pobox.corp.redhat.com (8.13.1/8.13.1) with ESMTP id m23GRMpP032522; Mon, 3 Mar 2008 11:27:22 -0500 Received: by opsy.redhat.com (Postfix, from userid 500) id 2E54337811A; Mon, 3 Mar 2008 08:36:30 -0700 (MST) To: Phil Muldoon Cc: frysk Subject: Re: follow-on{fork|clone} References: <47CC0BF7.2090604@redhat.com> From: Tom Tromey Reply-To: Tom Tromey X-Attribution: Tom Date: Mon, 03 Mar 2008 16:27:00 -0000 In-Reply-To: <47CC0BF7.2090604@redhat.com> (Phil Muldoon's message of "Mon\, 03 Mar 2008 14\:32\:23 +0000") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.0.990 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Scanned-By: MIMEDefang 2.58 on 172.16.52.254 X-IsSubscribed: yes Mailing-List: contact frysk-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: frysk-owner@sourceware.org X-SW-Source: 2008-q1/txt/msg00111.txt.bz2 Phil> Given that you turn off follow-on-fork sometimes (in GDB) is Phil> that mechanic useful for Frysk as well? Why do you turn it off? Phil> Is it because of bugs, or more of a focus? In gdb it is off by default. Or, more precisely, gdb just has one setting -- follow the parent or follow the child -- and it defaults to follow the parent. At least on FC-6, with the distro gdb, it is also buggy. I don't think I've had it work successfully. With CVS gdb it seems a bit better. So, it is a combo: partly bugs but partly because usually I want to follow the parent. This latter thing is a false dichotomy, my hope for frysk is that I won't have to choose. Phil> In writing watchpoints I personally cannot see why Phil> follow-on-{fork|clone} would ever be turned off One might imagine the debugger using too much memory as it attaches to and loads debug info for every application in a big hierarchy of fork/execs. (I have no idea how fhpd scales here.) In a situation like this you'd want to be able to control things more tightly. For the kind of debugging I'm doing right now, yeah, I would like to simply watch all the processes started from "gcc" and have fhpd show me when any of them crashes. That would be delightful and is really not possible with gdb today. Tom