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Interrupt Mitigation
Interrupt coalescing, also known as interrupt moderation, is a technique in which events which would normally trigger a hardware interrupt are held back, either until a certain amount of work is pending, or a timeout timer triggers. Used correctly, this technique can reduce interrupt load by up to an order of magnitude, while only incurring relatively small latency penalties. Interrupt coalescing is typically combined with either a hardware FIFO queue or direct memory access, to allow for continued data throughput while interrupts are being held back. Interrupt coalescing is a common feature of modern network cards, but the technique dates back to early computer UARTs such as the 16550 UART chip used in the IBM PC's serial interface, at a time when even servicing the interrupt rates required by the low data rate serial data streams of the day was taxing for contemporary CPUs. Interrupt coalescing can also be implemented without support in hardware, by disabling interrupts in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Hardware Interrupt
In digital computers, an interrupt (sometimes referred to as a trap) is a request for the processor to ''interrupt'' currently executing code (when permitted), so that the event can be processed in a timely manner. If the request is accepted, the processor will suspend its current activities, save its state, and execute a function called an '' interrupt handler'' (or an ''interrupt service routine'', ISR) to deal with the event. This interruption is often temporary, allowing the software to resume normal activities after the interrupt handler finishes, although the interrupt could instead indicate a fatal error. Interrupts are commonly used by hardware devices to indicate electronic or physical state changes that require time-sensitive attention. Interrupts are also commonly used to implement computer multitasking and system calls, especially in real-time computing. Systems that use interrupts in these ways are said to be interrupt-driven. History Hardware interrupts wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
