Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752858AbdLMMXc (ORCPT ); Wed, 13 Dec 2017 07:23:32 -0500 Received: from mail.free-electrons.com ([62.4.15.54]:33977 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752509AbdLMMXb (ORCPT ); Wed, 13 Dec 2017 07:23:31 -0500 Date: Wed, 13 Dec 2017 13:23:29 +0100 From: Alexandre Belloni To: Mark Brown Cc: Arnd Bergmann , Baolin Wang , Alessandro Zummo , Steven Rostedt , Ingo Molnar , linux-rtc@vger.kernel.org, LKML Subject: Re: [PATCH v2] rtc: Add tracepoints for RTC system Message-ID: <20171213122329.GU8318@piout.net> References: <64a38f4a15a2f8dae4a9fd0a3fc2a312e86c733d.1510749847.git.baolin.wang@linaro.org> <20171212221643.GL8318@piout.net> <20171213110426.GQ8318@piout.net> <20171213121603.GF6416@sirena.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171213121603.GF6416@sirena.org.uk> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 896 Lines: 20 On 13/12/2017 at 12:16:03 +0000, Mark Brown wrote: > On Wed, Dec 13, 2017 at 12:04:26PM +0100, Alexandre Belloni wrote: > > > Also, I think we could try having only the time64_t in the ring buffer. > > Maybe I'm wrong but I think tools reading that buffer can do the > > conversion themselves. Maybe I don't understand correctly how > > tracepoints work and this doesn't make sense, tell me. > > Tools reading the buffer can do the conversion themselves but it's also > useful for users to just view the log directly via tracing/trace > sometimes. OTOH the whole point is to be low overhead so... Yes, that is why I suggest keeping both representation in the printk but only time64_t in the buffer. And this would be more convenient if we add a way to pretty print a time64_t in vsprintf. -- Alexandre Belloni, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com