[X-Unix] limit cpu usage

[mac2]

> 
>> I've googled around, but haven't found an answer to this
>> question.  I would like to limit the max % cpu a process can
>> have.  Something similar to ulimit; however, ulimit only allows
>> limiting the number of cpu seconds a job can run.
> 
> 
> This is not philosophically possible on a Unix system.
> 
> What you want to do is a common resource control feature found in 
> Enterprise Class systems like VMS and MVS, but not Unix.

This is just wrong.  Solaris has the Resource Manager.  AIX has a similar 
utility built into the OS.

> 
> Over the years, there have been any number of companies who have written 
> Kernel code to create a "resource management" system for Unix -- but 
> they tend to cost big bucks and only run on "mainframe class" Unix boxes 
> ... AND, they never really work the way one expects them to work anyway.
> 
> The reason is a long discussion of Operating System theory, but briefly 
> put, Unix simply does not have the "hooks" necessary to implement any 
> useful kind of Resource Control.
>