Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S269477AbUICBIG (ORCPT ); Thu, 2 Sep 2004 21:08:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S269501AbUICBEv (ORCPT ); Thu, 2 Sep 2004 21:04:51 -0400 Received: from gateway-1237.mvista.com ([12.44.186.158]:41710 "EHLO av.mvista.com") by vger.kernel.org with ESMTP id S269477AbUICBAo (ORCPT ); Thu, 2 Sep 2004 21:00:44 -0400 Message-ID: <4137C1FA.7070000@mvista.com> Date: Thu, 02 Sep 2004 17:59:38 -0700 From: George Anzinger Reply-To: george@mvista.com Organization: MontaVista Software User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2.1) Gecko/20030225 X-Accept-Language: en-us, en MIME-Version: 1.0 To: OGAWA Hirofumi CC: Tim Schmielau , john stultz , Andrew Morton , Petri Kaukasoina , albert@users.sourceforge.net, lkml , voland@dmz.com.pl, nicolas.george@ens.fr, david+powerix@blue-labs.org Subject: Re: [PATCH] Re: boot time, process start time, and NOW time References: <87smcf5zx7.fsf@devron.myhome.or.jp> <20040816124136.27646d14.akpm@osdl.org> <412285A5.9080003@mvista.com> <1092782243.2429.254.camel@cog.beaverton.ibm.com> <1092787863.2429.311.camel@cog.beaverton.ibm.com> <1092781172.2301.1654.camel@cube> <1092791363.2429.319.camel@cog.beaverton.ibm.com> <20040819191537.GA24060@elektroni.ee.tut.fi> <20040826040436.360f05f7.akpm@osdl.org> <1093916047.14662.144.camel@cog.beaverton.ibm.com> <87fz61yf75.fsf@devron.myhome.or.jp> <4137896E.5080802@mvista.com> <87u0uggxme.fsf@devron.myhome.or.jp> In-Reply-To: <87u0uggxme.fsf@devron.myhome.or.jp> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1599 Lines: 48 OGAWA Hirofumi wrote: > George Anzinger writes: > > >>OGAWA Hirofumi wrote: >>Well, my machine says the result should be 996000000, so something is >>wrong with your or my math. > > > Hmm.. I don't know why. I'm using x86 cpu machine. > > >>As to if the initial jiffie value should >>be a multiple of HZ, I don't see why. I think it is several counts >>off of this value when the system wall clock is set in any case. > > > Ah, sorry for quite insufficiency explanation. > > Since INITIAL_JIFFIES is -5 minutes, so I though tv.tv_nsec should be 0. > The cause of this is > > INITIAL_JIFFIES % HZ (4294667296 % 1000) > > because INITIAL_JIFFIES is unsigned long. > > So, I guessed this is not intention. > Looks like this should be (-300*1000) % 1000. What "should be"? Are you refering to some real code or some thoughts you had? I am not aware of the kernel converting INITIAL_JIFFIES to time .... > > What do you think of this? The actual initial value of jiffies is not important. The reason this value was chosen was to catch problems that occur when the unsigned value rolls over to zero (and several were found and fixed). -- George Anzinger george@mvista.com High-res-timers: http://sourceforge.net/projects/high-res-timers/ Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml - 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/