Re: "Unknown HZ value! (0) Assume 100." Wraparound bug?

Re: "Unknown HZ value! (0) Assume 100." Wraparound bug?

[Albert Cahalan]

Matt Bernstein writes:

> Two of our machines (one running 2.4.18-xfs-ipsec, one
> running 2.4.19-pre10-ac2)  started spitting this message
> before some commands (might be in Debian procps 2.0.7-8)
> after an uptime of about 248 days (certainly in the latter
> case, probably the same in the former).
>
> This smells a bit as about 248 is about half of about 497,
> which was a trigger (which I managed to hit :) in the
> mid 2.1.x series for the uptime counter to wrap.

Yep. Debian-unstable has procps-3.1.5 now, which won't emit
this message with 2.4.xx and 2.5.xx kernels. Your system is
still inconsistant though, so rebooting would be a good idea.
(processes may appear to have been started in the future and
run for negative time)

The recent 2.5.xx kernels should be able to handle huge
uptimes better; you'll need the procps-3.1.6 release for
the most recent 2.5.xx kernels though.

http://procps.sf.net/

"Unknown HZ value! (0) Assume 100." Wraparound bug?

[Matt Bernstein]

Two of our machines (one running 2.4.18-xfs-ipsec, one running
2.4.19-pre10-ac2)  started spitting this message before some commands
(might be in Debian procps 2.0.7-8) after an uptime of about 248 days
(certainly in the latter case, probably the same in the former).

This smells a bit as about 248 is about half of about 497, which was a 
trigger (which I managed to hit :) in the mid 2.1.x series for the uptime 
counter to wrap.

Apart from the message the machines were still running fine. I rebooted 
the 2.4.18 one recently after about 330-340 days' uptime due to a power 
outage confusing its routing. The 2.4.19-pre10-ac2 one is our mail server 
and will need rebooting sooner as this bizarre message gets mailed back to 
anyone who mails any of our majordomo lists :-/

Anyway, can't grumble. Thanks for all the uptime :)

Matt