From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751883AbdFHVp1 (ORCPT ); Thu, 8 Jun 2017 17:45:27 -0400 Received: from mail-ot0-f173.google.com ([74.125.82.173]:36486 "EHLO mail-ot0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751547AbdFHVpZ (ORCPT ); Thu, 8 Jun 2017 17:45:25 -0400 MIME-Version: 1.0 In-Reply-To: References: <20170608134811.60786-1-andriy.shevchenko@linux.intel.com> <20170608134811.60786-5-andriy.shevchenko@linux.intel.com> <20170608150540.rek7a4akuxm3k36l@piout.net> <20170608184154.y7tqsv7ghpbcbf77@piout.net> <87wp8mky7z.fsf@rasmusvillemoes.dk> From: Arnd Bergmann Date: Thu, 8 Jun 2017 23:45:23 +0200 X-Google-Sender-Auth: XJnuzZtb0drsU_20mGpF6IDhn7I Message-ID: Subject: Re: [PATCH v1 04/25] lib/vsprintf: Print time and date in human readable format via %pt To: Andy Shevchenko Cc: Rasmus Villemoes , Alexandre Belloni , Andy Shevchenko , Rasmus Villemoes , Greg Kroah-Hartman , Andrew Morton , Linux Kernel Mailing List , Alessandro Zummo , linux-rtc@vger.kernel.org, Bartlomiej Zolnierkiewicz , Dmitry Torokhov , Geert Uytterhoeven , Guan Xuetao , Ingo Molnar , Jason Wessel , Jonathan Corbet , Jonathan Hunter , Krzysztof Kozlowski , "Rafael J. Wysocki" Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 8, 2017 at 11:25 PM, Andy Shevchenko wrote: > On Thu, Jun 8, 2017 at 11:42 PM, Rasmus Villemoes > wrote: >> On Thu, Jun 08 2017, Andy Shevchenko wrote: >>> On Thu, Jun 8, 2017 at 9:41 PM, Alexandre Belloni >>> wrote: >>>> On 08/06/2017 at 20:57:05 +0300, Andy Shevchenko wrote: >>>>> On Thu, Jun 8, 2017 at 6:05 PM, Alexandre Belloni >>>>> wrote: > >>> Yeah, but the problem is to pass the reference. All dances around will >>> uglify the code. >>> (Obviously we can't pass timespec64/time64_t or anything longer than >>> 32 bits as is in %p extension) > >> I like that this gets rid of some mm/dd/yy and other more or less random >> format and ends up standardizing yyyy-mm-dd HH:MM:SS. However, I do >> think %pt should take either ktime_t or timespec64 (obviously by >> reference), > > I will try to look in this direction. sounds good. >> Please don't give people the option of eliding either the time or the >> date; I've spent too much time dealing with syslog files that don't >> include the year in the timestamps. > > I understand that, but see above. When we pretty-print a ktime_t, we probably want to leave out the high fields as well, as this often refers to a time interval, e.g. a few seconds. Even for absolute values, the start of ktime_t is usually not the 1970 epoch but system boot, so we may not necessarily want the higher fields. I hoped to find some inspiration in the 'date' man page, which contains a lot of formatting options, but it's hard to translate that into a useful format string within the constraints of %p flags in printk. Arnd