NetBSD Problem Report #36530

From fukumoto@imasy.or.jp  Sat Jun 23 17:46:26 2007
Return-Path: <fukumoto@imasy.or.jp>
Received: from mail.netbsd.org (mail.netbsd.org [204.152.190.11])
	by narn.NetBSD.org (Postfix) with ESMTP id 5C1C263B882
	for <gnats-bugs@gnats.NetBSD.org>; Sat, 23 Jun 2007 17:46:26 +0000 (UTC)
Message-Id: <20070623174623.B2E874F38B@kestrel.imasy.or.jp>
Date: Sun, 24 Jun 2007 02:46:23 +0900 (JST)
From: fukumoto@imasy.or.jp
Reply-To: fukumoto@imasy.or.jp
To: gnats-bugs@NetBSD.org
Subject: High CPU temperature with XEN3_DOM0
X-Send-Pr-Version: 3.95


>Number:         36530
>Category:       port-xen
>Synopsis:       High CPU temperature with XEN3_DOM0
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    port-xen-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Jun 23 17:50:00 +0000 2007
>Last-Modified:  Wed Jun 04 02:15:02 +0000 2008
>Originator:     fukumoto@imasy.or.jp
>Release:        NetBSD 4.0_BETA2
>Organization:
>Environment:
System: NetBSD kestrel 4.0_BETA2 NetBSD 4.0_BETA2 (GENERIC.MP) #4: Sat Mar 31 04:34:08 JST 2007 fukumoto@kestrel:/usr/src.netbsd4/sys/arch/i386/compile/GENERIC.MP i386
Architecture: i386
Machine: i386
>Description:


CPU temperature is high with XEN3_DOM0 kernel even when 100% idle state.
No DOMU is running.
This has been same for xen 3.0.3, 3.0.4, 3.1.0 with netbsd-4 XEN3_DOM0.
Xen 2 + XEN2_DOM0 does not have this symptom.
Hardware is AMD Athlon 64 X2 on ASUS M2NPV-VM motherboard.
Temperature is measured using a modified it(4) (see pr/35796 for the detail of modification).


On Xen 3.1 + XEN3_DOM0, idle state:
   CPU Temp:     46.000 degC


For comparison, idle GENERIC.MP kernel:
   CPU Temp:     34.000 degC


GENERIC.MP kernel with 100% load (md5 /dev/zero)
   CPU Temp:     39.000 degC


GENERIC.MP kernel with 200% load (md5 /dev/zero & md5 /dev/zero &)
   CPU Temp:     53.000 degC
>How-To-Repeat:
set up xen3 and XEN3_DOM0, boot and measure CPU temperature
>Fix:


>Audit-Trail:
From: Christoph Egger <Christoph_Egger@gmx.de>
To: gnats-bugs@NetBSD.org
Cc: 
Subject: Re: port-xen/36530: High CPU temperature with XEN3_DOM0
Date: Tue, 03 Jun 2008 22:48:32 +0200


 Xen3 disables C1E resulting in more power consumption than in C1.
 This leads to the higher cpu temperature even when idling.

 
 In C1E state, the LAPIC is off and causes timer problems which in
 turn impact scheduling and the guest clock.
 That's why C1E is disabled.

 
 The "fix" would be to implement PowerNow support in NetBSD/Xen
 (Dom0 only feature). PowerNow support in Xen is partially
 available in Xen 3.2, better support will be in the coming Xen 3.3.

 
 Christoph

 
From: fukumoto@imasy.or.jp
To: gnats-bugs@NetBSD.org
Cc: port-xen-maintainer@netbsd.org, gnats-admin@netbsd.org,
        netbsd-bugs@netbsd.org
Subject: Re: port-xen/36530: High CPU temperature with XEN3_DOM0
Date: Wed, 04 Jun 2008 11:14:01 +0900


 Christoph Egger <Christoph_Egger@gmx.de> wrote:
 >>  Xen3 disables C1E resulting in more power consumption than in C1.
 >>  This leads to the higher cpu temperature even when idling.
 >>  

 
 I don't know what C1E does, but, googling "xen c1e" shows that Xen
 disable_c1e() patch is dated 2007-10-11, whereas the version I used
 was prior to that.  Wasn't it using C1E in older version?

 

 
 						FUKUMOTO Atsushi
 						fukumoto@imasy.or.jp

 
>Unformatted:

 	

 	

Home	PR Database Search