sysinfo, load average question

[Wayne Hayes]

In article <1990May23.160031.15723 at shibaya.lonestar.org> afc at shibaya.lonestar.org (Augustine Cano) writes:
>In article <1990May22.190038.5217 at bagend.uucp> jan at bilbo.uucp (Jan Isley) writes:
>>been running for many hours now with the usual background stuff going
>>on, reading news, a few megabytes of news coming in and going out, etc.
>>
>>The load average just read: 5.36 4.95 3.90.  Seems a bit high?
>>
>>Someone want to tell us again what these numbers really mean?
>
>They indicate (if I recall correctly) the load average in the last minute, in
>the last 5 minutes and in the last 15 minutes.  Why they are so high, I don't
>know (would someone care to enlighten me?)

Well, I don't have UNIX on my PC (just reading this group for info),
but on the Suns at school, the load average means "how many programs
are actively competing for CPU time?"  So, one CPU hog and nothing
else gives a load of exactly 1.00;  if you run 2 CPU hogs (and
nothing else) for 15 minutes and then sneak a load average check
(`uptime` on our Suns), it should read something like "2.10  2.02 2.00"
(the 1 minute and 5 minute loads are affected by the load-checking
command itself).  If all your processes are sleeping, it's 0.00.  On a
day that a big ass't is due at school here, I've seen the load average
upwards of 20, and even (rarely) near 40.  And when someone in the Unix
and C class doing the "write your own shell" ass't accidentally starts
a fork() inside an infinite loop, I've seen the average skyrocket to
over 200.  Of course the uptime command itself takes about 20 minutes
in this case, and the system is completely unusable.

    Hope this helps ...

-- 
Mathematics: That branch of Human Thought which takes a finite set of trivial
axioms and maps them to a countably infinite set of unintuitive theorems.

Wayne Hayes	INTERNET: wayne at csri.utoronto.ca	CompuServe: 72401,3525