From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758953AbZEFION (ORCPT ); Wed, 6 May 2009 04:14:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757237AbZEFIMy (ORCPT ); Wed, 6 May 2009 04:12:54 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:51032 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757379AbZEFIMw (ORCPT ); Wed, 6 May 2009 04:12:52 -0400 Date: Wed, 6 May 2009 10:12:25 +0200 From: Ingo Molnar To: Oleg Nesterov Cc: Andrew Morton , Roland McGrath , jdike@addtoit.com, utrace-devel@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [RFC, PATCH 0/2] utrace/ptrace: simplify/cleanup ptrace attach Message-ID: <20090506081225.GD8098@elte.hu> References: <20090503185537.GA17071@redhat.com> <20090504184951.623CEFC32F@magilla.sf.frob.com> <20090504193016.GA17076@redhat.com> <20090504194348.BC0EBFC32F@magilla.sf.frob.com> <20090504163154.f3672a83.akpm@linux-foundation.org> <20090505230642.GA980@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090505230642.GA980@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Oleg Nesterov wrote: > On 05/04, Andrew Morton wrote: > > > > On Mon, 4 May 2009 12:43:48 -0700 (PDT) > > Roland McGrath wrote: > > > > > I guess we should take Andrew's advice on this. To me, it > > > makes most sense just to order the -mm patches so utrace comes > > > later, and replace the utrace patch as necessary with a > > > compatible version. Perhaps things would be simpler if we > > > made a separate standalone series or git tree (tip/ptrace?) > > > for ptrace cleanups. > > > > Staging the utrace patch at end-of-series would make sense if > > utrace is not on track for a 2.6.31 merge. > > > > And afaict, this is indeed the case - things seem to have gone a > > bit quiet on the utrace front lately. > > The only goal of current ptrace cleanups is to simplify the > "ptrace over utrace" change (hopefully they make sense by > themselves though). > > I am obviously biased, but imho the only real problem with > utrace-ptrace.patch is the current ptrace code which needs > cleanups. Yes. But realize the fundamental reason for that: _without_ ptrace-over-utrace the utrace core code is a big chunk of dead code only used on the fringes. I see and agree with all the future uses of utrace, but it's easy to be problem-free if a facility is not used by anything significant. So a clean ptrace-over-utrace plugin is absolutely needed for utrace to go upstream in v2.6.31. The ftrace plugin alone does not justify it. The real prize here is a (much!) cleaner ptrace code. Once ptrace is driven via utrace and it works, its value (and trust level) will skyrocket. Ingo