Hi all, I am trying to understand in what extend the PGD (page global directory) value stored in the CR3 register indicate the running process/thread by the Linux scheduler. I know that each process has its own PGD value but what I am confused about is the value of CR3 register when kernel threads are scheduled. AFAIK, a "kernel thread" can 'borrow' the page-directory that belongs to another process (i.e. its address space). Does this apply *only* to threads of the same process (i.e. all the threads of process A are using the PGD entry of process A) or could also apply to threads not relevant to process A? That is, if a thread is executed and the value of CR3 at the time is 0x1E107000, does this *necessary* mean that a thread of the process with PGD 0xDE107000 is executed *or* a thread not relevant with that process could have 'borrowed' its PGD entry? Any help will be greatly appreciated. John K.