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Date: Tue, 13 Nov 2001 23:02:45 -0800 (PST)
From: Ming Zhang <ming@unixbox.com>
To: freebsd-gnats-submit@FreeBSD.org
Subject: microuptime() went backwards when apm is already disabled in the kernel on intel CPU
X-Send-Pr-Version: www-1.0

>Number:         31971
>Category:       kern
>Synopsis:       microuptime() went backwards when apm is already disabled in the kernel on intel CPU
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    phk
>State:          closed
>Quarter:        
>Keywords:       
>Date-Required:  
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Nov 13 23:10:01 PST 2001
>Closed-Date:    Tue Jul 29 03:31:02 PDT 2003
>Last-Modified:  Tue Jul 29 03:31:02 PDT 2003
>Originator:     Ming Zhang
>Release:        4.4-Stable
>Organization:
>Environment:
FreeBSD shell.unixbox.com 4.4-STABLE FreeBSD 4.4-STABLE #1: Fri Oct 26 15:56:38 PDT 2001     root@shell.unixbox.com:/usr/src/sys/compile/unixbox  i386
  
>Description:
microuptime() went backwards (1569221.6122007 -> 1569220.755141)

it happens every other 3-4 days.

Machine is a PIII-650Mhz on ASUS CUV 4X
APM is already disabled from kernel (never was configured)

Never seen this before upgrading to 4.4
>How-To-Repeat:
      Don't know	
>Fix:
      I thought you may know....
>Release-Note:
>Audit-Trail:

From: David Malone <dwmalone@maths.tcd.ie>
To: Ming Zhang <ming@unixbox.com>
Cc: freebsd-gnats-submit@FreeBSD.org
Subject: Re: kern/31971: microuptime() went backwards when apm is already disabled in the kernel on intel CPU
Date: Wed, 14 Nov 2001 10:41:55 +0000

 On Tue, Nov 13, 2001 at 11:02:45PM -0800, Ming Zhang wrote:
 > >Description:
 > microuptime() went backwards (1569221.6122007 -> 1569220.755141)
 > 
 > it happens every other 3-4 days.
 > 
 > Machine is a PIII-650Mhz on ASUS CUV 4X
 > APM is already disabled from kernel (never was configured)
 > 
 > Never seen this before upgrading to 4.4
 
 Can you try running "sysctl kern.timecounter" and see what it
 outputs. You could try setting kern.timecounter.method to 1 or
 experimenting with kern.timecounter.hardware (which can probably
 be set to i8254 or TSC on your hardware).
 
 	David.

From: Ming Zhang <ming@unixbox.com>
To: David Malone <dwmalone@maths.tcd.ie>
Cc: <freebsd-gnats-submit@FreeBSD.org>
Subject: Re: kern/31971: microuptime() went backwards when apm is already
 disabled in the kernel on intel CPU
Date: Wed, 14 Nov 2001 09:26:23 -0800 (PST)

 Hi, here it's the output:
 
 # sysctl kern.timecounter
 kern.timecounter.method: 0
 kern.timecounter.hardware: TSC
 
 I've set kern.timecounter to 1 and will see if that stops the prob.
 
 thanks
 
 Ming
 
 On Wed, 14 Nov 2001, David Malone wrote:
 
 > On Tue, Nov 13, 2001 at 11:02:45PM -0800, Ming Zhang wrote:
 > > >Description:
 > > microuptime() went backwards (1569221.6122007 -> 1569220.755141)
 > >
 > > it happens every other 3-4 days.
 > >
 > > Machine is a PIII-650Mhz on ASUS CUV 4X
 > > APM is already disabled from kernel (never was configured)
 > >
 > > Never seen this before upgrading to 4.4
 >
 > Can you try running "sysctl kern.timecounter" and see what it
 > outputs. You could try setting kern.timecounter.method to 1 or
 > experimenting with kern.timecounter.hardware (which can probably
 > be set to i8254 or TSC on your hardware).
 >
 > 	David.
 >
 
State-Changed-From-To: open->feedback 
State-Changed-By: iedowse 
State-Changed-When: Sun Dec 1 12:30:05 PST 2002 
State-Changed-Why:  

Does this still happen on more recent releases? 

http://www.freebsd.org/cgi/query-pr.cgi?pr=31971 
Responsible-Changed-From-To: freebsd-bugs->phk 
Responsible-Changed-By: kris 
Responsible-Changed-When: Sat Jul 12 16:21:38 PDT 2003 
Responsible-Changed-Why:  
phk is Mr Timekeeping 

http://www.freebsd.org/cgi/query-pr.cgi?pr=31971 
State-Changed-From-To: feedback->closed 
State-Changed-By: phk 
State-Changed-When: Tue Jul 29 03:30:50 PDT 2003 
State-Changed-Why:  
timed out. 

http://www.freebsd.org/cgi/query-pr.cgi?pr=31971 
>Unformatted:
