On multiprocessor systems, interrupts sent between the CPUs coordinate and synchronize timing, I/O, and other cooperative activity.
You can use cpusar -j to see how active interrupt handling routines are on a particular CPU in a multiprocessor system. If device drivers are not written to be multithreaded, they will only run on the base processor. You can examine which device drivers are multithreaded using the mthread(ADM) command. You can also use the displayintr(ADM) command to see how interrupt handlers are distributed across the system's CPUs and whether they are movable from one CPU to another.
The number of inter-CPU interrupts can be examined
using mpsar -I to view systemwide activity or
cpusar -I to examine an individual CPU.
The output of these commands depends on your system hardware.