From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21100 invoked by alias); 27 Nov 2007 16:42:58 -0000 Received: (qmail 21089 invoked by uid 22791); 27 Nov 2007 16:42:58 -0000 X-Spam-Check-By: sourceware.org Received: from mtagate3.de.ibm.com (HELO mtagate3.de.ibm.com) (195.212.29.152) by sourceware.org (qpsmtpd/0.31) with ESMTP; Tue, 27 Nov 2007 16:42:51 +0000 Received: from d12nrmr1607.megacenter.de.ibm.com (d12nrmr1607.megacenter.de.ibm.com [9.149.167.49]) by mtagate3.de.ibm.com (8.13.8/8.13.8) with ESMTP id lARGgmMQ123492 for ; Tue, 27 Nov 2007 16:42:48 GMT Received: from d12av02.megacenter.de.ibm.com (d12av02.megacenter.de.ibm.com [9.149.165.228]) by d12nrmr1607.megacenter.de.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id lARGglVU2916408 for ; Tue, 27 Nov 2007 17:42:47 +0100 Received: from d12av02.megacenter.de.ibm.com (loopback [127.0.0.1]) by d12av02.megacenter.de.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id lARGglUE031752 for ; Tue, 27 Nov 2007 17:42:47 +0100 Received: from tuxmaker.boeblingen.de.ibm.com (tuxmaker.boeblingen.de.ibm.com [9.152.85.9]) by d12av02.megacenter.de.ibm.com (8.12.11.20060308/8.12.11) with SMTP id lARGglTe031746; Tue, 27 Nov 2007 17:42:47 +0100 Message-Id: <200711271642.lARGglTe031746@d12av02.megacenter.de.ibm.com> Received: by tuxmaker.boeblingen.de.ibm.com (sSMTP sendmail emulation); Tue, 27 Nov 2007 17:42:47 +0100 Subject: Re: Non-stop multi-threaded debugging To: nathan@codesourcery.com (Nathan Sidwell) Date: Tue, 27 Nov 2007 16:42:00 -0000 From: "Ulrich Weigand" Cc: gdb@sourceware.org, jimb@codesourcery.com (Jim Blandy) In-Reply-To: <4743178A.3050501@codesourcery.com> from "Nathan Sidwell" at Nov 20, 2007 05:21:14 PM X-Mailer: ELM [version 2.5 PL2] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit 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: 2007-11/txt/msg00245.txt.bz2 Nathan Sidwell wrote: > A client of CodeSourcery's has contracted with us to implement a > number of new features in GDB, some of which have been on the > frequently requested list for quite some time: Thanks, these are indeed very interesting and useful features. > - We're to implement a limited form of multi-process debugging. > > Full multi-process debugging would entail changes to > 1) process management code, > 2) target interfaces, and > 3) symbol tables. > Our client would very much like for this work to be incorporated into > the public GDB sources (although they understand that the decision is > in the public project's hands), so we'll be posting our design > thoughts for general discussion. In particular, I believe the > multi-process work may overlap with some of the work IBM has done to > support the Cell processor; we'd very much like to work with IBM to > ensure that the final model is appropriate for both our client and for > Cell developers. It looks like the points 1) and 2) you are planning to address actually do *not* overlap with the work we've been doing on the Cell combined debugger. The Cell programming model our debugger supports is bascially a regular multi-threaded model, except that some threads may execute either PowerPC or SPU architecture code at any time. Multi-process support is not required. [ However, of course multi-process support would be a nice *extension* to the Cell combined debugger, allowing to debug multiple processes, each of which follows the normal multi-threaded Cell model. ] Point 3) above would be relevant to the Cell combined debugger as well. You do not address this point in more detail in your document, but I assume this would imply introducing the notion of "address spaces" and associating symbol tables to a particular address space. Something similar is already needed for the Cell combined debugger, as we have multiple address spaces even within a single process. I'm definitely interested in working on adding this support to mainline GDB -- if that then also helps the multi-process work, that's an additional benefit. Bye, Ulrich -- Dr. Ulrich Weigand GNU Toolchain for Linux on System z and Cell BE Ulrich.Weigand@de.ibm.com