From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759444Ab3DAWxq (ORCPT ); Mon, 1 Apr 2013 18:53:46 -0400 Received: from mail-pb0-f45.google.com ([209.85.160.45]:46801 "EHLO mail-pb0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759421Ab3DAWxn (ORCPT ); Mon, 1 Apr 2013 18:53:43 -0400 Message-ID: <515A0E69.2040604@gmail.com> Date: Mon, 01 Apr 2013 16:47:05 -0600 From: David Ahern User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:17.0) Gecko/20130307 Thunderbird/17.0.4 MIME-Version: 1.0 To: John Stultz CC: Linux Kernel Mailing List , Thomas Gleixner , Steven Rostedt Subject: Re: [PATCH] timekeeping: Add tracepoints for xtime changes - v2 References: <1363710477-4203-1-git-send-email-dsahern@gmail.com> <515A0317.1070800@gmail.com> <515A072A.3080307@linaro.org> In-Reply-To: <515A072A.3080307@linaro.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/1/13 4:16 PM, John Stultz wrote: > I guess what I'm getting at is: What ABI are we creating here? Can > these tracepoints come and go without any consequence? Or would changing > them in the future cause application breakage? > > I'm somewhat worried even trace_tod_update() is maybe too vague (again > not that the name specifically is critical, but that the semantics we're > specifying are clear). In other words, I think you're wanting a > tracepoint at any time CLOCK_REALTIME is updated by anything other then > the normal progression of time? Is that right? yes. essentially everywhere timekeeping_update() is called except update_wall_time(). > > You may want to also include the leapsecond modification in the tracing > as well. I thought those were covered as well. hmm... maybe not if it triggers in update_wall_time. David