Hi everyone,

I'm trying to setup a system where I can synchronise a 100kHz (10us) process through PCI on an interrupt base. There is 
a huge problem with the kernel at this frequency of interrupting. The thing is, when giving my ISR (with noting more 
than an out32()) a priority higher than every other system process, it stil takes about 3 us for the interrupt to be 
handeled. Extually this is not the main problem.

When interrupting at this frequency the systemload tends to be enormous. With kernel event trace (momentics) I get a 
systemload of 100% and 80-90% is used bij system. Resulting in the fact that the proccessor can't do anything else 
inbetween.

How is it possible that the ISR takes up so much of system resources, even when the ISR itself doesn't do that much? It 
isnt't that big of a problem that the interrupt latency itself is x us but that the system is busy 100% means that I 
can't do anything else!