From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754862AbcJLVXi (ORCPT ); Wed, 12 Oct 2016 17:23:38 -0400 Received: from mout.gmx.net ([212.227.15.19]:58777 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751969AbcJLVXa (ORCPT ); Wed, 12 Oct 2016 17:23:30 -0400 To: "john.stultz@linaro.org" , "linux-kernel@vger.kernel.org" , "linux-parisc@vger.kernel.org" From: Helge Deller Subject: timekeeping: Cycle offset (32) is larger than allowed by the 'jiffies' clock's max_cycles value (10): time overflow danger X-Enigmail-Draft-Status: N1110 Message-ID: <57FEA996.3030004@gmx.de> Date: Wed, 12 Oct 2016 23:22:30 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K0:SNhRZIrKD4N3iSAkJCwnfPSUF3mrEZ7oK/FCOkO/bXheYE3IlnO Okr/qCNBsUGp9KfUrdGQbQFV97O6ztJPgyg0CBAC6k2ToQeFJwVe/k0tbsukRpwUI++IHIZ fdzrDjcGGkVymSP/4XkLG3oX0KAp7u3P0lYXRLGx63FNiw2znghrURdc1WGJYX7weTDb2QK JkVO6YMv0jX8RL9jNmAnA== X-UI-Out-Filterresults: notjunk:1;V01:K0:vX/J5F2dPrs=:Id3EeqWyQ9fkdp0BTDn1mR IYb+Mj1oT00D48fId+7rGRFM+/zPj5DvuVSvJNN/rL61vUEvZl9hOQPSWJAOOsw15OPGhr+hf i6nFFBCQlDf9Zq7VLhNEI+VwPnICApN0+PTKI0JOxmu1fm3tifB6Iz+bqrikycpW0yCliJTLV OcRLYD/6/fIARzZjVeEEbsP48ndOpd3QWOUq39qelN2ox+SSQ+QPkrgQl5QQzloFUWP+4OjV8 m6h0QJg4I7082gL4fz0pMobt8eYXRrlDeyvTfO8zufyCCHk1KvRcAtYMumkbcgjh7A2yJasS+ fI3dwE1ZlpDrqBf7Z2cInqY9qNrb6j4e8UHpLPllNldUrBMngmX6Bme46zHucIw59jfbAV1bu gGzUr1YU/vxKnQmIroVbYV8nYd4V9Eg7giG2wKWgfITP5brIpwpazSA9i7DSh+84sLhZs4InO aTKhF2be/UBhibvAoSC6weKAgYvkCR+x9sYqY/ZykPGKDg/FKMvSPK0xi1FmPh9ExlBQrvfmv UlgbJi+bzyta7mzd/BcCMLeOWSaKD5gaSc/fbUVYrQ1a/TEyGr1n7Z1+Sflzb0MYzDytIY7GK 0HluWVUxlinUnGogRppY6wnbfdCLQjh7FAeXjRxygn/J5G/C22ERX7gQZhCX2hDg/pcc/r1pP VClzkmjj7XzLvLc9cXzcDgnCvVdz16WVspN4FbC92ufDT4g/hszLhPHXCkmM6VNsD+DeshZoq jwR7C1nwXcLyHT8H2xZsbrNxAkLz7lMs9SponqHaMQDTBA8bt/fdr9l/0Cv7/Zhf9TyMEjrA1 lVMjZ9y Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When enabling CONFIG_DEBUG_TIMEKEEPING, I see on kernel 4.8 git head those warnings on the parisc architecture: Linux version 4.8.0-64bit+ (deller@p100.box) (gcc version 4.9.2 20150212 (Red Hat Cross 4.9.2-5) (GCC) ) #516 SMP Wed Oct 12 22:52:58 CEST 2016 ... clocksource: cr16: mask: 0xffffffffffffffff max_cycles: 0xacf9151134, max_idle_ns: 440795214493 ns WARNING: timekeeping: Cycle offset (32) is larger than allowed by the 'jiffies' clock's max_cycles value (10): time overflow danger timekeeping: Your kernel is sick, but tries to cope by capping time updates WARNING: timekeeping: Cycle offset (42) is larger than allowed by the 'jiffies' clock's max_cycles value (10): time overflow danger timekeeping: Your kernel is sick, but tries to cope by capping time updates ... At this stage the jiffies clocksource was not yet registered (at least not mentioned in the bootlog). This warning happens over and over. Maybe it should be rate-limited too? Comparing to 4.7 where CONFIG_DEBUG_TIMEKEEPING is not enabled I see: root@c8000:~# dmesg | grep clock [ 0.000000] clocksource: cr16: mask: 0xffffffffffffffff max_cycles: 0xcf914c9718, max_idle_ns: 440795231327 ns [ 0.873644] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645041785100000 ns [ 7.968087] clocksource: Switched to clocksource cr16 Am I somehow missing to initialize the max_cycles field of the jiffies clocksource on the parisc architecture ? Helge