Subject: Re: is load average reported correctly??
To: Jason Thorpe <thorpej@nas.nasa.gov>
From: None <Chris_G_Demetriou@NIAGARA.NECTAR.CS.CMU.EDU>
List: current-users
Date: 01/17/1996 20:03:49
> On Tue, 16 Jan 1996 08:50:00 -0600 
>  Chris Csanady <ccsanady@friley14.res.iastate.edu> wrote:
> 
>  > hi, i was just wondering if the load avg is reported correctly in current.
>  > i am curious, because for some reason, my load avg is constantly at about
>  > .10 or so, whether i have 2 or 75 processes.  if this is so, does this not
>  > mean that the system is using 10% of my cpu time even when idle?  if so,
>  > why?  most systems that i have used are usually at 0.00 when idle..
> 
> Actually, load average is now calculated _correctly_.  cgd would be best 
> to explain the bug and his fix.

I've actually explained it before, on current-users, i think...

Quick recap:

Correct instantaneous load average is:
	(number of runnable processes) +
	(number of processes that have been in uninterruptable wait
	    for less than a second).

The bug was that the second term was being calculated at a time when
it could never be non-zero...


your system _should_ have a load average of 0.00 when idle...  but
depending on system activity and the type of system, it may never be
_completely_ idle, and it may take a fair bit of "work" (that would
show up in the load average) to calculate the load average, esp. if
you're running something other than 'uptime' (e.g. 'w') to do it.


chris