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What will the interrupt handler do?
The job of the interrupt handler is to service the device and stop it from interrupting. Once the handler returns, the CPU resumes what it was doing before the interrupt occurred. The Solaris 7 DDI/DKI provides a bus-architecture independent interface for registering and servicing interrupts.
What is interrupt handler with example?
The traditional form of interrupt handler is the hardware interrupt handler. For example, pressing a key on a computer keyboard, or moving the mouse, triggers interrupts that call interrupt handlers which read the key, or the mouse’s position, and copy the associated information into the computer’s memory.
What happens if we call schedule () in interrupt handler?
When you are in interrupt context, you cannot call any blocking function (e.g., schedule() ) or access the current pointer. That’s related to how the kernel is designed and there is no way for having such functionalities in interrupt context.
What precautions should be taken while writing an interrupt handler?
These precautions typically take the form of special entry and exit code sequences. Save registers and other state information that interrupt-processing might modify to preserve the execution of the code. Prepare the CPU environment before executing the main body of the interrupt handler.
Why should interrupts be short?
Because interrupts prevent other interrupts from running. Keep them short basically just means do no more than you need to in the interrupt. This requires nested interrupts (to allow interrupts to interrupt each other) which can get messy.
What should I know about interprocessor interrupt handling?
A CPU issued an interrupt to another CPU of a multiprocessor system. We cover such interrupts in the later section ” Interprocessor Interrupt Handling .” In general, an I/O interrupt handler must be flexible enough to service several devices at the same time.
How is an interrupt handler different from other handlers?
Unlike other event handlers, interrupt handlers are expected to set interrupt flags to appropriate values as part of their core functionality. Even in a CPU which supports nested interrupts, a handler is often reached with all interrupts globally masked by a CPU hardware operation.
Can a system freeze during an interrupt handler?
Most important, the process on behalf of which an interrupt handler is executed must always stay in the TASK_RUNNING state, or a system freeze can occur. Therefore, interrupt handlers cannot perform any blocking procedure such as an I/O disk operation.
How are software interrupts similar to hardware interrupts?
Later it was found convenient for software to be able to trigger the same mechanism by means of a software interrupt (a form of synchronous interrupt). Rather than using a hard-coded interrupt dispatch table at the hardware level, software interrupts are often implemented at the operating system level as a form of callback function .