From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LNcNN-0000bt-Vq for qemu-devel@nongnu.org; Thu, 15 Jan 2009 19:15:54 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LNcNM-0000bE-Dj for qemu-devel@nongnu.org; Thu, 15 Jan 2009 19:15:53 -0500 Received: from [199.232.76.173] (port=38263 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LNcNM-0000b7-6f for qemu-devel@nongnu.org; Thu, 15 Jan 2009 19:15:52 -0500 Received: from mx20.gnu.org ([199.232.41.8]:43840) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1LNcNK-0005yd-DA for qemu-devel@nongnu.org; Thu, 15 Jan 2009 19:15:51 -0500 Received: from mail.codesourcery.com ([65.74.133.4]) by mx20.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1LNcNH-0005L8-Ko for qemu-devel@nongnu.org; Thu, 15 Jan 2009 19:15:47 -0500 From: Paul Brook Subject: Re: [Qemu-devel] Re: [RESEND][PATCH] gdbstub: Add vCont support Date: Fri, 16 Jan 2009 00:15:44 +0000 References: <496DFA33.2020606@siemens.com> <496F9D75.4020802@codemonkey.ws> <496FAA5D.3000403@web.de> In-Reply-To: <496FAA5D.3000403@web.de> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200901160015.44729.paul@codesourcery.com> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Jan Kiszka > a) Modeling cpus as processes buys us nothing compared to threads given > the fact that we cannot provide a stable memory mapping to the gdb > frontend anyway. (*) I disagree. The process model fits perfectly. The whole point is that each CPU has its own virtual address space. Separate address spaces is the fundamental difference between a process and a thread. If you have a multicore system where several cores share a MMU[1] then modelling these as threads probably make sense. Don't confuse this with OS awareness in GDB (i.e. implementing a userspace debug environment via a bare metal kernel level debug interface). That's a completely separate issue. > b) The model is already part of mainline qemu. This patch is just > about adding even more usefulness to it. I have no problems with ripping out the bogus "thread" support once (or even before) proper process support is implemented. Likewise I've no problem requiring a recent GDB if you want to do multicore debugging. Paul [1] or have no MMU at all.