What happens when two interrupts occur at the same time in linux kernel

linux linux-kernel linux-device-driver irq
Adi picture Adi · Mar 25, 2014 · Viewed 10.1k times · Source

What happens when two interrupts occur at the same time in the Linux kernel..?

If that processor has more than one CPU can the interrupts run on different cpu cores at the same time.

Answer

wallyk picture wallyk · Mar 25, 2014

There is always a hierarchy of interrupt signals. The highest priority one is the first seen by the CPU and acted upon. Once that is done, the then next highest priority interrupt is handled. It is possible that a third interrupt signal of higher priority than the first two has arrived since, so it will be handled out of order, which is the point of priority.

Linux has support for interrupt affinity so that one IRQ is always routed to a particular CPU or group of CPUs. Poke around in /proc/interrupts.

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