Inter-processor interrupt

<p>In <a href="/facts/Computing/Kghtm9fX">computing</a>, an inter-processor interrupt (IPI), also known as a <i>shoulder tap</i>, is a special type of <a href="/facts/Interrupt/Mm6C4rpc">interrupt</a> by which one <a href="/facts/Processor_(computing)/z3wPljrI">processor</a> may interrupt another processor in a <a href="/facts/Multiprocessor/aDCfehDQ">multiprocessor</a> system if the interrupting processor requires action from the other processor.  Actions that might be requested include:
</p>
<ul><li>flushes of <a href="/facts/Memory_management_unit/tJQtAQzI">memory management unit</a> caches, such as <a href="/facts/Translation_lookaside_buffer/vvwGkfvD">translation lookaside buffers</a>, on other processors when memory mappings are changed by one processor;</li>
<li>stopping when the system is being shut down by one processor.</li>
<li>Notify a processor that higher priority work is available.</li>
<li>Notify a processor of work that cannot be done on all processors due to, e.g.,
<ul><li>asymmetric access to <a href="/facts/I/O_channel/vDBtN2wQ">I/O channels</a></li>
<li>special features on some processors</li></ul></li></ul>

Inter-processor interrupt open-in-new

Inter-processor interrupt