freebsd stable - Dec 2006 - negative runtime etc., the story continues

Hi,
I wrote about how FreeBSD 6.1 RC1, with latest RELENG_6 kernel, prints loads
of "calcru: runtime went backwards..." and "calcru: negative
runtime..."
messages when the FreeBSD runs as virtual server under Microsoft Virtual
Server 2006 R2. When I wrote this I was compiling and installing lots of
packages, setting up the OS. Now that it is idle I have noticed one quite bad
thing. Any process that sleeps on timer or sleep() call will wake up much
later than it should. For example, when I start top there should be two
seconds delay between updates of the screen. It takes up to 20 seconds! But
when there is compilation running or something else CPU intensive, the timer
seems to work fine.

I even tried setting different kern.timecounter.hardware (TSC, ACPI-safe,
i8254) and kern.hz (to lower than the default 1000) but that did not help a bit.

Is there anything I can do to get rid of the calcru messages apart from
reinstalling to real hardware?

--
Vaclav Haisman

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 542 bytes
Desc: OpenPGP digital signature
Url :
http://lists.freebsd.org/pipermail/freebsd-stable/attachments/20061219/b1313a5a/signature.pgp

On Tue, Dec 19, 2006 at 11:49:43PM +0100, V??clav Haisman
wrote:
> Hi,
> I wrote about how FreeBSD 6.1 RC1, with latest RELENG_6 kernel, prints
loads
> of "calcru: runtime went backwards..." and "calcru: negative
runtime..."
> messages when the FreeBSD runs as virtual server under Microsoft Virtual
> Server 2006 R2. When I wrote this I was compiling and installing lots of
> packages, setting up the OS. Now that it is idle I have noticed one quite
bad
> thing. Any process that sleeps on timer or sleep() call will wake up much
> later than it should. For example, when I start top there should be two
> seconds delay between updates of the screen. It takes up to 20 seconds! But
> when there is compilation running or something else CPU intensive, the
timer
> seems to work fine.
> 
> I even tried setting different kern.timecounter.hardware (TSC, ACPI-safe,
> i8254) and kern.hz (to lower than the default 1000) but that did not help a
bit.
> 
> Is there anything I can do to get rid of the calcru messages apart from
> reinstalling to real hardware?
Last time I was trying to run FreeBSD as a guest OS in MS VS, I
found that TSC would work the best, but only if I made sure that
the TSC frequency was correct.  For some weird reason, the frequency
initially detected by the kernel was totally bogus and changing
from one boot to another, so I just estimated it from cpu-z output
in the host OS, and it fairly worked.  I still couldn't get rid of
the annoying warnings, especially when under load.

-- 
Yar