Subject: Re: Jerky/frozen mouse under load
To: Jakub Misak <email@example.com>
From: Matthias Buelow <firstname.lastname@example.org>
Date: 02/15/2005 19:33:39
Jakub Misak wrote:
> And like I said, NetBSD 1.6 was very smooth on the same PC with the same
> software, drivers and settings. And multitasking in Linux is also a lot
> smoother than it is in NetBSD 2.0 on the same PC, with the same
Another point concerning the scheduler, doesn't anybody notice the
nonsensical load values that uptime, top etc. report? Nonsensical, in
the way of, unconventional. I don't know exactly how NetBSD measures or
defines the CPU "load" (last time I wanted to look that up in the
source, I was left a bit confused) but traditionally it's the number of
"runnable" processes at a given time, averaged over some time interval.
Uptime reports load averaged over 1, 5 and 15 minutes. However, the
reported load values are far too high, and they go up too fast aswell.
As soon as disk i/o is involved, it seems to me that things get counted
double, or even triple. Packing up pkgsrc with pax into a file (no
pipeline, no gzip) almost immediately pushes the load over 1 from under
0.10, after about 1-2 seconds (which should be impossible, considering
that the first value is supposed to be averaged over 1 minute), and
after a while it sticks at around load 3, even though only one process
is running (pax), and top displays around 80% idle. Even if kernel time
would be included, shouldn't it go no higher than 1.0, given that the
system is otherwise idle? Also, load on an idle system always seems to
be around 0.10, instead of 0.0 which one can observe on other systems.
This isn't something that appeared with NetBSD 2.0, however, I have
observed this with earlier releases aswell.