Re: kern/56322: Excessive clock drift

[Frank Kardel <kardel%kardel.name@localhost>]

The following reply was made to PR kern/56322; it has been noted by GNATS.

From: Frank Kardel <kardel%kardel.name@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: kern/56322: Excessive clock drift
Date: Thu, 22 Jul 2021 10:10:51 +0200

 On 07/22/21 09:00, David Holland wrote:
 
 >   
 >    >  Can you try
 >    >
 >    >  sysctl -w kern.timecounter.hardware=i8254
 >    >
 >    >  and see whether that improves the situation.
 >   
 >   Yes.
 >   
 >   As of ~now when I did that it had dropped to two full minutes behind,
 >   in something like seven hours, so tomorrow morning should indicate
 >   whether the situation's better.
 >   
 120s / 25200 sec ~ 0.0048 = 4800ppm
 
 Something must be really wrong with TSC frequency estimation or 
 stability on that system.
 Also I would have expected a timecounter like hpet. Could that be 
 disabled in the BIOS?
 >   --
 >   David A. Holland
 >   dholland%netbsd.org@localhost
 >   
 Frank