Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755378AbaJNQq0 (ORCPT ); Tue, 14 Oct 2014 12:46:26 -0400 Received: from mail-ig0-f178.google.com ([209.85.213.178]:40811 "EHLO mail-ig0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752580AbaJNQqY (ORCPT ); Tue, 14 Oct 2014 12:46:24 -0400 MIME-Version: 1.0 In-Reply-To: References: <1413285078-7027-1-git-send-email-huishao@microsoft.com> <20141014111915.GV23154@mwanda> Date: Tue, 14 Oct 2014 17:46:24 +0100 Message-ID: Subject: Re: [PATCH 2/2] hyperv: Implement Time Synchronization using host time sample From: Mike Surcouf To: Thomas Shao Cc: Dan Carpenter , "tglx@linutronix.de" , "gregkh@linuxfoundation.org" , "linux-kernel@vger.kernel.org" , "devel@linuxdriverproject.org" , "olaf@aepfle.de" , "apw@canonical.com" , "jasowang@redhat.com" , KY Srinivasan Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >The value for TICK_USEC is defined as ((1000000UL + USER_HZ/2) / USER_HZ). > In my box, it's 10000. OK got it thanks . Checked the algorithm OK by me. Of course you can only adjust clock by a tick (smallest resolution) so you could be flapping between 2 values so as you say NTP is preferred. However it may be good enough for some scenarios. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/