From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from baldric (baldric.uwo.ca [129.100.10.225]) by dsl2.external.hp.com (Postfix) with ESMTP id 06594483E for ; Sun, 21 Sep 2003 08:27:17 -0600 (MDT) Date: Sun, 21 Sep 2003 10:24:58 -0400 From: Carlos O'Donell To: Helge Deller Cc: Joel Soete , parisc-linux@parisc-linux.org Subject: Re: [parisc-linux] sched_clock implementation Message-ID: <20030921142458.GE6963@systemhalted> References: <20030918203510.GD21596@parcelfarce.linux.theplanet.co.uk> <3F6C9622.60402@tiscali.be> <20030921000447.GC31268@dsl2.external.hp.com> <200309211320.36485.deller@gmx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <200309211320.36485.deller@gmx.de> Sender: parisc-linux-admin@lists.parisc-linux.org Errors-To: parisc-linux-admin@lists.parisc-linux.org List-Help: List-Post: List-Subscribe: , List-Id: parisc-linux developers list List-Unsubscribe: , List-Archive: On Sun, Sep 21, 2003 at 01:20:36PM +0200, Helge Deller wrote: > On Sunday 21 September 2003 02:04, Grant Grundler wrote: > > On Sat, Sep 20, 2003 at 06:02:10PM +0000, Joel Soete wrote: > > > a quick look into paxx.pdf which about CR16 speak of "peak instruction > > > rate" but do not define anywhere? > > > I presume that is the cpu clock but would like somebody confirm. > > > > Read about "Interval Timer" (cr16) in the PA 2.0 Arch book. > > PDC provides the exact rate that CR16 is changing. > > Looks like PDC_TOD_ITIMER is the call but I'm not sure offhand. > > In any case, I've only seen it used as CPU cycle counter. > > (ie 1:1 with CPU clock). > > Hi Joel, > > I think we have the rate in the variable "boot_cpu_data.cpu_hz" (see > arch/parisc/kernel/processor.c) already. Technically that's our highest precision timer :) c.