Bug 18949

Summary: infinite "microuptime() went backwards" messages -- caused by intense disk access
Product: Base System Reporter: sussman <sussman>
Component: kernAssignee: freebsd-bugs (Nobody) <bugs>
Status: Closed FIXED    
Severity: Affects Only Me    
Priority: Normal    
Version: Unspecified   
Hardware: Any   
OS: Any   

Description sussman 2000-06-01 17:40:01 UTC 
This problem is identical, I think, to kern/18858, and possibly kern/18798.

The "microuptime() went backward" messages are so numerous, that my
system becomes destabilized;  the CPU load stays quite high,
everything slows down, I have to reboot.  There's no way to stop the
messages once they get started.

Fix: 

?
How-To-Repeat: Intense UDMA disk access on this particular motherboard.

I can *absolutely* reproduce it by doing
any sort of prolonged, intense disk access -- for example, building
the "ispell" port.  (ispell builds some huge indices.)
Comment 1 Poul-Henning Kamp freebsd_committer freebsd_triage 2000-06-10 20:16:09 UTC 
State Changed
From-To: open->feedback

Please try with a kernel without APM support 
Please include dmesg and sysctl kern.timecounter output.
Comment 2 alex freebsd_committer freebsd_triage 2000-06-12 09:59:33 UTC 
State Changed
From-To: feedback->closed

The originator said, that the problem disappeared with a non-APM kernel.