Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268594AbUIGVAI (ORCPT ); Tue, 7 Sep 2004 17:00:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268270AbUIGVAI (ORCPT ); Tue, 7 Sep 2004 17:00:08 -0400 Received: from omx3-ext.sgi.com ([192.48.171.20]:46498 "EHLO omx3.sgi.com") by vger.kernel.org with ESMTP id S268609AbUIGU7y (ORCPT ); Tue, 7 Sep 2004 16:59:54 -0400 Date: Tue, 7 Sep 2004 13:55:53 -0700 (PDT) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: George Anzinger cc: Andi Kleen , john stultz , lkml , tim@physik3.uni-rostock.de, albert@users.sourceforge.net, Ulrich.Windl@rz.uni-regensburg.de, Len Brown , linux@dominikbrodowski.de, David Mosberger , paulus@samba.org, schwidefsky@de.ibm.com, jimix@us.ibm.com, keith maanthey , greg kh , Patricia Gaughen , Chris McDermott Subject: Re: [RFC] New Time of day proposal (updated 9/2/04) In-Reply-To: <413DFCC2.7080405@mvista.com> Message-ID: References: <1094159238.14662.318.camel@cog.beaverton.ibm.com> <20040903151710.GB12956@wotan.suse.de> <1094242317.14662.556.camel@cog.beaverton.ibm.com> <20040904130022.GB21912@wotan.suse.de> <413DFCC2.7080405@mvista.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 906 Lines: 19 On Tue, 7 Sep 2004, George Anzinger wrote: > Also, we don't "know" what rate the TSC is actully clocking so we must > "discover" it at boot time. This process either is inaccurate or slow (I think > we use ~ 50 ms these days which gives an error of ~10 TSC cycles on a 800MHZ > box). FWIW the problem here is the sync up with the I/O backplane to find the > start and ending of the measured time. > > I suspect that the IA64 "tells" you what its clock rate is. Right? Not the CPU itself. There is a special hardware I/O interface called the PAL/SAL that allows one to retrive that information. Doesnt the BIOS on i386 allow you to get to that information? - 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/