An
interrupt
is a notification from a device that tells
the kernel that:
An action such as a disk transfer has been completed.
Data such as keyboard input or a mouse event has been received.
The kernel services an interrupt within the
context
of the current process that is running on the CPU.
The execution of the current process is suspended
while the kernel deals with the interrupt in system mode.
The process may then lose its place on the CPU as
a result of a context switch. If the interrupt signaled
the completion of an I/O transfer, the scheduler
wakes the process that was
sleeping on
that event, and puts it on a run queue at a newly calculated numeric
priority.
It may or may not be the next process to run
depending on this priority.