[altq 883] Re: Configuration of Altq

[Kenjiro Cho <kjc@csl.sony.co.jp>]

Karl Pielorz wrote:
> > You can use "exactbandwidth" to specify less than 1% in CBQ.
> > See altq.conf(5).
> >
> > But be aware that our CBQ implementation may not have the precision of
> > 1/1000.
> 
> Didn't this used to cause rounding errors, that resulted in queues 
> 'jamming' when their allocation was less than 1% (i.e. a fraction, 0.4%)? 
> Or has this been fixed now, and I missed it?

I guess it's the following entry in CHANGES:

2000/01/29	altq/altq_rmclass.c:
		add a workaround that clears undertime when a class is
		resumed to avoid eventual outage under a long stress test.

		somehow, the kernel timer expires earlier than the expected
		time under certain conditions on FreeBSD (the cause of this
		phenomenon is not known).
		when this happens, a resumed class could get suspended
		immediately after its resume for another offtime.

	    	report by  George Uhl <uhl@mamba-e.gsfc.nasa.gov> in [altq-120]
		and Karl Pielorz <kpielorz@tdx.co.uk>

-Kenjiro