Please comment on the following sentence:
On the standard Linux kernel without the rt patch, interrupts can't interrupt ongoing system calls. The reason why our machine doesn't stop working when data is fetched from the hard disk is because the system call we used for that operation is blocking. Blocking means that once it issues the request to the hard disc it changes the process state to blocked, and willingly gives up the processor time. There are no means to interrupt an ongoing system call on a non real time kernel.
This is my understanding of the topic, I am however, not sure if it is correct.