title: Purpose of self-IPI on IA-32
body: <p>What is the purpose of a processor sending an Inter Processor Interrupt to itself on the IA-32 architecture? </p>
  
  <p>According to the Intel IA-32 Architecture Software Developer's Manual, Vol. 3, Ch. 10.1:</p>
  
  <blockquote>
    <p>IPIs are used for software self-interrupts, interrupt forwarding, or 
    preemptive scheduling.</p>
  </blockquote>
  
  <p>But why would you use a self IPI when the processor can also interrupt itself with an INT instruction? This feature seems to be redundant.</p>