Firstly Linux has a timer resolution of about 0.9uS, it has a clock running
at 100Hz but the two are different. gettimeofday() returns a very accurate
figure.
There is a Linux over real time executive project, being led by Victor
Yodaiken (a search for the name will find you the web links to this). This
is doing hard real time as opposed to the soft real time already present.
Alan