Hoping that someone may have had this problem and can give me a quick direction. I am using RTL2.0pre5. I modified the measurement example to increment a char value every millisecond. The char value is shared via mbuff. Everything runs well but when I try to rmmod my process the machine stops dead (no mouse no response no new line even). The thread has a while(1) loop that it is executing in with a wait_np(). the module_cleanup first kills the thread, frees shared memory, then closes and destroys the FIFO. I am trying to isolate the problem now but printk's in the module clean up code do not show up either. Any help is appreciated, John --- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl <Your_email>" | mail [EMAIL PROTECTED] ---- For more information on Real-Time Linux see: http://www.rtlinux.org/~rtlinux/