From mboxrd@z Thu Jan 1 00:00:00 1970 From: Giuliano Colla Subject: CLOCK_MONOTONIC issue Date: Mon, 22 Jun 2015 13:06:28 +0200 Message-ID: <5587EC34.2070808@fastwebnet.it> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15; format=flowed Content-Transfer-Encoding: 7bit To: linux-rt-users@vger.kernel.org Return-path: Received: from mr004msr.fastwebnet.it ([85.18.95.67]:53441 "EHLO mr004msr.fastwebnet.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753921AbbFVLMQ (ORCPT ); Mon, 22 Jun 2015 07:12:16 -0400 Received: from microserver.localdomain (151.41.156.223) by mr004msr.fastwebnet.it (8.5.140.03) (authenticated as giuliano.colla) id 54FF13C4065674D8 for linux-rt-users@vger.kernel.org; Mon, 22 Jun 2015 13:06:30 +0200 Sender: linux-rt-users-owner@vger.kernel.org List-ID: Hi all, in order both to profile the performance of my rt threads, and to perform timed operations (such as sem_timedwait), I'm using the clock_gettime() function. Using as a parameter CLOCK_REALTIME everything appears to work as expected, but if I attempt to use CLOCK_MONOTONIC (which should be a more reliable timing source, from what I read), I get bogus times. This occurs on different platforms, and with different kernel versions/rt patch. (3.10.10-rt7 - 3.10.67-rt71 - 3.12.31-rt45). Am I missing something obvious, such as a kernel misconfiguration, or this is something to be expected? Any hint will be appreciated. Thanks in advance, Giuliano -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in