In a dual core processor, Do both the processors halt execution when an interrupt occurs?

Question

suppose two cores of a CPU are running two threads parallelly, and an interrupt occurs one on of them, does the other processor also stop execution ?

Answer 1

You'll find more information in this article: Why interrupt affinity with multiple cores is not such a good thing

Every x86 motherboard has a chip called IO-APIC. This is a device that controls interrupt delivery within your system. It knows how many CPUs are in your system and can direct various interrupts to various CPUs. It uses so called local APIC-ID as an identifier of the processor.

It has two modes of operation. In one mode it sends interrupts from certain device to single, predefined core. This mode of operation called fixed/physical mode. In another mode, it can deliver interrupts from certain device to multiple cores. The later mode called logical/low priority interrupt delivery mode.

See also this patent from IBM: Interrupt dispatching method in multi-core environment and multi-core processor