On Thu, May 18, 2000 at 02:13:22PM -0500, Ruibiao Qiu wrote:

 > So, I wonder if usleep() can get to less than 10 ms.  Does it has
 > anything to do with system clock resolution?  How can I find out
 > the current value of it?  How can I configure it?   Do I need 
 > to use nanosleep()?  (BTW, when I run the tests on a linux box, I
 > got 20 ms :)

Yes, in fact, it has everything to do with the system clock resolution.
The system clock ticks every 10ms, so that is the minimum scheduling
granularity.

Try building your kernel with:

options HZ=256

That would make the granularity slightly less than 5ms, and might work
on a PC.

-- 
        -- Jason R. Thorpe <thorpej@zembu.com>