Bug 31971

Summary: microuptime() went backwards when apm is already disabled in the kernel on intel CPU
Product: Base System Reporter: ming <ming>
Component: kernAssignee: Poul-Henning Kamp <phk>
Status: Closed FIXED    
Severity: Affects Only Me    
Priority: Normal    
Version: Unspecified   
Hardware: Any   
OS: Any   

Description ming 2001-11-14 07:10:01 UTC 
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

Fix: 

I thought you may know....
How-To-Repeat:       Don't know
Comment 1 dwmalone 2001-11-14 10:41:55 UTC 
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.
Comment 2 ming 2001-11-14 17:26:23 UTC 
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.
>
Comment 3 iedowse freebsd_committer freebsd_triage 2002-12-01 20:30:05 UTC 
State Changed
From-To: open->feedback


Does this still happen on more recent releases?
Comment 4 Kris Kennaway freebsd_committer freebsd_triage 2003-07-13 00:21:38 UTC 
Responsible Changed
From-To: freebsd-bugs->phk

phk is Mr Timekeeping
Comment 5 Poul-Henning Kamp freebsd_committer freebsd_triage 2003-07-29 11:30:50 UTC 
State Changed
From-To: feedback->closed

timed out.