Subject: Re: Nice processes on Unix
From: (Rob Warnock)
Date: Fri, 06 Jun 2008 05:54:35 -0500
Newsgroups: comp.lang.lisp
Message-ID: <>
Tim Bradshaw  <> wrote:
| On Jun 6, 7:37 am, Madhu <> wrote:
| > `loadavg' is a measure of contention -- [see manpage definition below]
| > loosely it is the number of processes trying to run simultaneously
| > (contending for CPU) or waiting for IO (contending for Disk).  Someone
| > from google once told me that if this number is greater than 1 "your
| > system is in trouble", as the system is overloaded.
| I'm not sure how much it varies between implementations, but
| traditionally, and simplifying somewhat, the load average is the
| number of processes which are not waiting for anything other than I/O
| in order to run (ie this does not count processes which are waiting
| for you to type something, say).

<FLAME value="on">
Unfortunately for computer science, historical practice, sanity,
and just plain common sense, Linux has decided to include in the
"load average" *all* processes that are *waiting* for *any* I/O
completions, whether from swapping disks or slow file disks or
networks or slow serial lines or paper tape readers! This results
in such nonsense, for example, as often seeing a "load average"
of 150+ on a *TOTALLY IDLE* NFS server that just happens to have
a large number of mounts on it. (*sigh*)

Whereas sane operating systems such as TOPS-10, TOPS-20, Irix, Solaris,
{Free,Net,Open}BSD, and many others include in the load average only
processes that are waiting to get a *CPU* on which to run.


Rob Warnock			<>
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