An interrupt is an electrical signal delivered to the processor indicating occurrence of a significant event that needs immediate attention. These signals can originate either from external hardware (connected to the system) or from circuits within the processor. In this chapter we will look into the kernel's interrupt management subsystem and explore the following:
- Programmable interrupt controllers
- Interrupt vector table
- IRQs
- IRQ chip and IRQ descriptors
- Registering and unregistering interrupt handlers
- IRQ line-control operations
- IRQ stacks
- Need for deferred routines
- Softirqs
- Tasklets
- Workqueues