The Jargon File (version 4.4.7, 29 Dec 2003):

interrupts locked out
 adj.

    When someone is ignoring you. In a restaurant, after several fruitless
    attempts to get the waitress's attention, a hacker might well observe ?She
    must have interrupts locked out?. The synonym interrupts disabled is also
    common. Variations abound; ?to have one's interrupt mask bit set? and ?
    interrupts masked out? are also heard. See also spl.