From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933015AbcBXIsa (ORCPT ); Wed, 24 Feb 2016 03:48:30 -0500 Received: from mail-wm0-f67.google.com ([74.125.82.67]:36370 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756110AbcBXIs0 (ORCPT ); Wed, 24 Feb 2016 03:48:26 -0500 Date: Wed, 24 Feb 2016 09:48:22 +0100 From: Ingo Molnar To: Steven Rostedt Cc: Peter Zijlstra , Daniel Bristot de Oliveira , Ingo Molnar , Thomas Gleixner , Juri Lelli , Arnaldo Carvalho de Melo , LKML , linux-rt-users Subject: Re: [PATCH 3/4] sched/deadline: Tracepoints for deadline scheduler Message-ID: <20160224084822.GC22868@gmail.com> References: <20160222173259.GM6357@twins.programming.kicks-ass.net> <20160222124854.3816fec4@gandalf.local.home> <20160222213017.GN6357@twins.programming.kicks-ass.net> <20160222173043.24873ae8@gandalf.local.home> <20160223104408.GO6357@twins.programming.kicks-ass.net> <20160223081046.529d615c@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160223081046.529d615c@gandalf.local.home> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Steven Rostedt wrote: > On Tue, 23 Feb 2016 11:44:08 +0100 > Peter Zijlstra wrote: > > > No it very much illustrates the problem and is a very clear indication > > that tracepoints are an ABI. > > Yes they are. But note, they can change if nobody notices ;-) Which is rather seldom for something as high profile as core scheduler tracepoints ... You can be cavalier about tracepoints in subsystems where the tracepoints are at most used by the maintainers with specialized, closely maintained tooling that is easy to change. Not so much about scheduler tracepoints which are being widely utilized by various projects. Thanks, Ingo