Re: Load average and CPU hogs in realtime scheduling

Rik van Riel (
Mon, 17 Nov 1997 12:17:29 +0100 (MET)

On Sun, 16 Nov 1997, Olaf Titz wrote:

> MAME (arcade machine emulator) is cool. :-) In order to let it run
> smoothly, I run it in SCHED_FIFO (or was ist _RR?) mode (the svgalib
> version). This program seems to take 100% of the CPU time and no other
> process on the machine gets to run, not surprisingly.
> What does surprise me, however: when I exit MAME and let my machine
> resume normal operation, it displays a load average of perhaps 15 or
> 20, depending on how long MAME ran, despite no processes in R or D
> state. The load drops quickly to the usual "0+noise".
> Looks like there is something slightly wrong with load average
> computation.

Perfectly OK. When you are running MAME, there will (no doubt) be
some other programs that want to run. Because MAME is getting all
the CPU time, the other programs will be waiting on the queue, thus
pushing up the load.
When MAME gets exited, the other processes get run and also quit
(or go back to sleep) so you can't see they are (have been)


Send Linux memory-management wishes to me: I'm currently looking
for something to hack...