From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752117Ab3BOUD3 (ORCPT ); Fri, 15 Feb 2013 15:03:29 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52096 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751940Ab3BOUD1 (ORCPT ); Fri, 15 Feb 2013 15:03:27 -0500 Message-ID: <511E9480.5070202@redhat.com> Date: Fri, 15 Feb 2013 20:03:12 +0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Oleg Nesterov CC: Andrey Vagin , linux-kernel@vger.kernel.org, criu@openvz.org, linux-api@vger.kernel.org, Andrew Morton , "Paul E. McKenney" , David Howells , Dave Jones , "Michael Kerrisk (man-pages)" , Pavel Emelyanov , Linus Torvalds Subject: Re: [PATCH] ptrace: add ability to retrieve signals without removing them from a queue References: <1360768595-31943-1-git-send-email-avagin@openvz.org> <511E8223.6010506@redhat.com> <20130215194356.GA12413@redhat.com> In-Reply-To: <20130215194356.GA12413@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Forgot to reply to this bit: On 02/15/2013 07:43 PM, Oleg Nesterov wrote: >> We'd miss the poke >> > variant, but that looks like something that could be always be added >> > later. > Yes. _POKE_ or _QUEUE_ or _DEQUEUE_, we can add more features if user- > space wants them. In general, IMO, I agree with Roland at https://lkml.org/lkml/2002/12/20/84 in that it's good to have setters for completeness, so that you can change all the state via ptrace that you can read via ptrace. But I'm not doing any of this work, hence my "could always be added later" comment instead of actually requesting it. But if we had it, we could make e.g., gdb inspect the signal queues, and then be able to tweak a realtime signal before it is delivered. -- Pedro Alves