From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751800AbcFRTBi (ORCPT ); Sat, 18 Jun 2016 15:01:38 -0400 Received: from mout.kundenserver.de ([217.72.192.74]:56860 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751639AbcFRTBg (ORCPT ); Sat, 18 Jun 2016 15:01:36 -0400 From: Arnd Bergmann To: Jeff Moyer Cc: Jens Axboe , Steven Rostedt , Ingo Molnar , y2038@lists.linaro.org, Hannes Reinecke , Mike Christie , Shaohua Li , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] blktrace: avoid using timespec Date: Sat, 18 Jun 2016 21:02:08 +0200 Message-ID: <3744206.k1Hv7RyTzG@wuerfel> User-Agent: KMail/5.1.3 (Linux/4.4.0-22-generic; KDE/5.18.0; x86_64; ; ) In-Reply-To: References: <20160617145849.3771756-1-arnd@arndb.de> <57646E09.9080408@kernel.dk> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:L1+wBW8vJfw777ha/Exm3lKCdWZ60x183n3eahu2rgA2AKwkK3I amjOfAnS3pbwPSRTNOQgmzqB7gvwrT5cnnRdkW4WsNaSGcE2k2FY+eqk/yH/xTJJpX7HwD+ sCEKkhbuFhd8XkuGUfvnnx73eFR33xnWfQb7873IefkfrWL9kaGzv3mLrtGrvTHmJS0/Gz/ hENDFlpYt+tmnTREg3c6g== X-UI-Out-Filterresults: notjunk:1;V01:K0:sZ7LhXui3Fc=:ccSGRBML1UawcqKG2Knha3 iR3wBvbsSc2esw4rjnGP83wPCRZaNZVW9ho65+6QuPINOASQIqFzRiFp10SMS3ksuO4aTkKSP hyNjd5M4sPIPzVanbGGPuFIWOF+jo8GXEgDiXa2pRdOgK8yu5x5oMLxMiwj6Aw/657BVFlpVo IKzIyPsE5OjtixFxqlIP/pfduByJ3asScdI1tukss2+smDO5zDndHYOhHDtQuHZWBCiC3OjSZ kBvhTcWuHLsx61yV/cyzYheCHVaonqJih/03NdhxWCQOtO5/RliZDCs37FumZ/iiHPOL5Bmyg 6PTJG0t1fy+PkpIGyoaU+02c7DdnFvgpZU70v3A8QYBZM7iL6dFjCyRTM1PThPVqPdh5WnR1U pUaP96FLYj+KC08HEvKlZA9yFle5nb/ytrmasceEKCdk+rib9O8Ya4tXhX+Tw32YnZZ32sWot fn1JRI174DspSWB2zeBnYt//Ev32mqlv17MyYjUKExjETs2qjtR2wWxtGbg4S7aNmfj8Kd+2I ZOHOeSrKiN5H28VNvKGEvk8KozqF2MI7HZ3fn0CvBK4OeIjvWq/NsHwHfn1CFFnlCBtPEK09+ RwYUMxSjUdqktdGzpyR1BaIkGsPD9T0OGyQ2EGifUJv0yZxfkqItB6OWOzzFvYO76Sc+W6sRF bCDOEqK6uEMxggtv40+B2bakARC0XEO0Qhyjei2Z3ye2yMnph/arlNYeBktg5keXLB8j7fhtm df+B9kFTmI381+2Z Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday, June 17, 2016 5:54:16 PM CEST Jeff Moyer wrote: > Jens Axboe writes: > > > On 06/17/2016 05:36 PM, Steven Rostedt wrote: > >> > >> Jens, > >> > >> You want to take this, or do you want me to? > > > > I'll add it to my 4.8 tree, thanks Arnd. > > + /* need to check user space to see if this breaks in y2038 or y2106 */ > > Userspace just uses it to print the timestamp, right? So do we need the > comment? If we have more details, the comment should describe what happens and when it overflows. If you have the source at hand, maybe you can answer these: How does it print the timestamp? Does it print the raw seconds value using %u (correct) or %d (incorrect), or does it convert it into year/month/day/hour/min/sec? In the last case, how does it treat second values above 0x80000000? Are those printed as year 2038 or year 1902? Are we sure that there is only one user space implementation that reads these values? Arnd