[wellylug] Renicing

[David Antliff]

On Thu, 23 Feb 2006, E.Chalaron wrote:
> How much faster can I expect an application to be when I renice it to small
> numbers.
> And how small can I go ?  It is a small script running for hours at night,
> apart from the system no extra pid are launched.

The nice level doesn't make an application run faster, it just decreases 
(or increases) the frequency at which it enters the kernel scheduler's run 
queue relative to other processes. If nothing else is happening on the 
machine, then a process will run at the same speed regardless of it's nice 
value. It's a relative thing (i.e. depends on nice value of all other 
processes).

You can go from -20 (highest priority) to 19. Only root can decrease the 
nice value.

See 'man nice'

Be cautious - I have set certain things to -20 and subsequently regretted 
it...

-- 
David.