Hi 
     I recently find if I want access memory from io mmu in qnx. how to resolve the cache coherent ? 
As I know, in unix like system .They will use the task schedule to run the mataincode to keep the memory cache coherent 
in kernel mode .

But . I have question on how to implementer this function in qnx ? or any other micro kernel OS . 

This is not from any project , It's just personal interesting . So ,If you have time , this is really confuse me .