From owner-freebsd-i386@FreeBSD.ORG  Wed Mar 28 12:24:39 2007
Return-Path: <owner-freebsd-i386@FreeBSD.ORG>
X-Original-To: freebsd-i386@freebsd.org
Delivered-To: freebsd-i386@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
	by hub.freebsd.org (Postfix) with ESMTP id 4C79316A40B
	for <freebsd-i386@freebsd.org>; Wed, 28 Mar 2007 12:24:39 +0000 (UTC)
	(envelope-from rpaulo@gmail.com)
Received: from wr-out-0506.google.com (wr-out-0506.google.com [64.233.184.228])
	by mx1.freebsd.org (Postfix) with ESMTP id ED7DB13C4E8
	for <freebsd-i386@freebsd.org>; Wed, 28 Mar 2007 12:24:38 +0000 (UTC)
	(envelope-from rpaulo@gmail.com)
Received: by wr-out-0506.google.com with SMTP id 70so1584504wra
	for <freebsd-i386@freebsd.org>; Wed, 28 Mar 2007 05:24:38 -0700 (PDT)
DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta;
	h=domainkey-signature:received:received:message-id:date:from:sender:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition:x-google-sender-auth;
	b=QuUgJTtT5nbpZ6ah+US7qYeZWnXlWuyKgGECBSya5ePZvihkUNh0+XxUT1dhETiVfR6T2PJG49G/XTmzTzLbVh9T0ciggCk41hs5Py4XHjiyK5mpZFN4TgzONveMbfJwmJjT2LTARr6rI3ieW202Dz90hBFJmtY0RIvH8Vo4mPs=
DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta;
	h=received:message-id:date:from:sender:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition:x-google-sender-auth;
	b=S2I21pq1eHSHnZ2ARTaaCtgeRH+cHgghRL82jF42zouaixudYm8TxMYF4qd9e3GFoH0pUtOAGxs8oDC4RFgzDp8uA8nSaXm+aDaZBfAbB4PJPEMa+Vm+srD/cyn5cuYnPoSLbyVrS6nqlCDmCHKkPVSQy/sgA0zuhl49RYlSj78=
Received: by 10.114.107.19 with SMTP id f19mr3657566wac.1175083044181;
	Wed, 28 Mar 2007 04:57:24 -0700 (PDT)
Received: by 10.114.132.18 with HTTP; Wed, 28 Mar 2007 04:57:24 -0700 (PDT)
Message-ID: <e1309ba60703280457v394e7263x17f0e93512d11ad4@mail.gmail.com>
Date: Wed, 28 Mar 2007 12:57:24 +0100
From: "Rui Paulo" <rpaulo@fnop.net>
Sender: rpaulo@gmail.com
To: freebsd-i386@freebsd.org
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
X-Google-Sender-Auth: 29ec73272603c035
Subject: Timecounting issue
X-BeenThere: freebsd-i386@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: I386-specific issues for FreeBSD <freebsd-i386.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-i386>,
	<mailto:freebsd-i386-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-i386>
List-Post: <mailto:freebsd-i386@freebsd.org>
List-Help: <mailto:freebsd-i386-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-i386>,
	<mailto:freebsd-i386-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 28 Mar 2007 12:24:39 -0000

Hi,
I have a machine only knows to count time if I'm using TSC.

For example:
# sysctl kern.timecounter.hardware=ACPI-fast && time sleep 1 && sysctl
 kern.timecounter.hardware=i8254 && time sleep 1 && sysctl
kern.timecounter.hardware=HPET && time sleep 1 && sysctl
kern.timecounter.hardware=TSC && time sleep 1

Gives:
kern.timecounter.hardware: HPET -> ACPI-fast
sleep 1  0.00s user 0.00s system 0% cpu 1.517 total
kern.timecounter.hardware: ACPI-fast -> i8254
sleep 1  0.00s user 0.00s system 0% cpu 1.516 total
kern.timecounter.hardware: i8254 -> HPET
sleep 1  0.00s user 0.00s system 0% cpu 1.516 total
kern.timecounter.hardware: HPET -> TSC
sleep 1  0.00s user 0.00s system 0% cpu 1.006 total

This happens if I enable SMP or not.

Any hint on how to debug this ?

Thanks