strange load peaks with recent kernels

Rob Janssen (rob@pe1chl.ampr.org)
Fri, 26 Apr 96 10:52 MET DST


Yesterday I installed 1.3.95 after having used 1.3.69 for a couple
of weeks (after I got nothing but problems somewhere in the 1.3.7x series).

This kernels looks like being stable, but I still see the funny load
average peaks that also showed up somewhere in 1.3.7x when I tried those
before.
This is most apparent when running xload, but it can also be seen in top.
Sometimes the load just goes up to 1 or 2 without apparent reason (with
the usual exponential ramp-up and ramp-down).
Often the load just climbs to that level and then immediately starts
falling down again, like:

2 - /\
/ \
1 - /\ / \
/ \ / \
0 -/ \/ \-------------

It seems like it often happens when the X server has entered the screen
saver while some process that displays output is on the currently active
screen area. But this isn't the only cause for sure, I sometimes see
the load go to 1 and stay there for half an hour while the screen is
switched on and "top" shows no processes taking noticable CPU time.

It also looks like the "noise" above the 0-level when the system is idle
and there happens to be no load peak at the time has a higher amplitude
than it had with older kernels.

I have seen others mentioning this before, but apparently it was not yet
solved. Is this happening on all systems? Or maybe only on some
configurations?

Rob