Call to the scheduler...

[Damien TOURAINE]

Hi !
I would like to implement a system to actively wait something but 
without eating a lot of CPU.
Thus, I would like to know if there is any way to force the scheduler of 
Linux to pre-empt the current process/thread, like the "sginap(0)" 
function within IRIX.
Moreover, I don't want to have to be root to execute such function.

Friendly
    Damien TOURAINE