Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932333Ab0LNQ3R (ORCPT ); Tue, 14 Dec 2010 11:29:17 -0500 Received: from hera.kernel.org ([140.211.167.34]:40801 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756683Ab0LNQ3O (ORCPT ); Tue, 14 Dec 2010 11:29:14 -0500 Message-ID: <4D079B19.4010606@kernel.org> Date: Tue, 14 Dec 2010 17:28:09 +0100 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.2.13) Gecko/20101207 Lightning/1.0b2 Thunderbird/3.1.7 MIME-Version: 1.0 To: Linus Torvalds CC: "Suzuki K. Poulose" , linux-kernel@vger.kernel.org, Jeremy Fitzhardinge , Christoph Hellwig , Masami Hiramatsu , Ananth N Mavinakayanahalli , Daisuke HATAYAMA , Andi Kleen , Roland McGrath , Amerigo Wang , KAMEZAWA Hiroyuki , KOSAKI Motohiro , Oleg Nesterov , Andrew Morton Subject: Re: [RFC] [Patch 0/21] Non disruptive application core dump infrastructure References: <20101214152259.67896960@suzukikp> <4D079541.3090405@kernel.org> In-Reply-To: X-Enigmail-Version: 1.1.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Tue, 14 Dec 2010 16:28:11 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1144 Lines: 29 Hello, Linus. On 12/14/2010 05:19 PM, Linus Torvalds wrote: > On Tue, Dec 14, 2010 at 8:03 AM, Tejun Heo wrote: >> >> I think a better way would be adding a ptrace attach which is nestable >> and doesn't have the nasty side effect caused by the interactions >> between the implicit SIGSTOP and group stop. > > Don't we already nest at least to some degree? At least you can strace > a gdb session or another strace, no? Yes, it depends on what the 'nesting' means. I was thinking about gcore'ing or attching gdb to an already strace'd process. This might not be strictly necessary but for ptrace attach to be transparent, we need another PTRACE_* call anyway as PTRACE_ATTACH implies SIGSTOP and having nestable attach would be beneficial in several use cases including using debugging tools nested and allowing userland checkpointing of debugging sessions. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/