From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sakari Ailus Subject: 32 kHz timer granularity when CONFIG_NO_HZ is enabled Date: Wed, 22 Oct 2008 16:13:02 +0300 Message-ID: <48FF26DE.4060107@nokia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from smtp.nokia.com ([192.100.122.230]:23672 "EHLO mgw-mx03.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752466AbYJVNNZ (ORCPT ); Wed, 22 Oct 2008 09:13:25 -0400 Received: from vaebh105.NOE.Nokia.com (vaebh105.europe.nokia.com [10.160.244.31]) by mgw-mx03.nokia.com (Switch-3.2.6/Switch-3.2.6) with ESMTP id m9MDD4mp011793 for ; Wed, 22 Oct 2008 16:13:22 +0300 Received: from [127.0.0.1] (localhost [127.0.0.1]) by maxwell.research.nokia.com (Postfix) with ESMTP id 3B88427B15D for ; Wed, 22 Oct 2008 16:13:03 +0300 (EEST) Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "linux-omap@vger.kernel.org" Hi, I have OMAP 3 and I'm using the 32 kHz timer, CONFIG_OMAP_32K_TIMER_HZ is set to 128 and CONFIG_NO_HZ is enabled. Many OMAP-based boards in arch/arm/config seem to have this kind of default configuration. This has the effect that for example msleep(1) sleeps much longer than intended, between 7,8 and 15,6 ms, for no apparent good reason. I'm just wondering whether all this is intentional. :-) -- Sakari Ailus sakari.ailus@nokia.com