From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Thu, 05 Jun 2003 21:05:00 +0100 (BST) Received: from 66-122-194-201.ded.pacbell.net ([IPv6:::ffff:66.122.194.201]:18049 "EHLO localhost.localdomain") by linux-mips.org with ESMTP id ; Thu, 5 Jun 2003 21:04:58 +0100 Received: from localhost.localdomain (greglaptop [127.0.0.1]) by localhost.localdomain (8.12.8/8.12.5) with ESMTP id h55K6WOW001670 for ; Thu, 5 Jun 2003 13:06:32 -0700 Received: (from lindahl@localhost) by localhost.localdomain (8.12.8/8.12.8/Submit) id h55K6W9m001668 for linux-mips@linux-mips.org; Thu, 5 Jun 2003 13:06:32 -0700 X-Authentication-Warning: localhost.localdomain: lindahl set sender to lindahl@keyresearch.com using -f Date: Thu, 5 Jun 2003 13:06:32 -0700 From: Greg Lindahl To: linux-mips@linux-mips.org Subject: Re: [RFC] synchronized CPU count registers on SMP machines Message-ID: <20030605200632.GA1513@greglaptop.internal.keyresearch.com> Mail-Followup-To: linux-mips@linux-mips.org References: <20030604153930.H19122@mvista.com> <20030604231547.GA22410@linux-mips.org> <20030604164652.J19122@mvista.com> <20030605001232.GA5626@linux-mips.org> <20030604183836.B25414@mvista.com> <16094.64161.12926.645512@doms-laptop.algor.co.uk> <20030605084852.GA25712@linux-mips.org> <20030605095348.C25414@mvista.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030605095348.C25414@mvista.com> User-Agent: Mutt/1.4.1i Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 2547 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: lindahl@keyresearch.com Precedence: bulk X-list: linux-mips On Thu, Jun 05, 2003 at 09:53:48AM -0700, Jun Sun wrote: > 1) yes, it is always possible to use some external system-wide > timer source, if available, to solve this problem. However, that could > get tricky too, and I wanted to do something generic which is hopefully > applicable to more systems. Such sources are generally both much lower resolution, and they take a long time to read. But a _consistent_ but higher overhead, lower resolution number is better than an inconsistent number. greg