Examples include interrupting a processing resource based on a last interrupt request indicator and a work acknowledgement. Some examples include completion of work associated with a plurality of work units, storage of a last interrupt request indicator to specify a last completed work unit that includes a request to interrupt a processing resource, comparison of work unit information associated with the last interrupt request indicator with work unit information associated with a work acknowledgement generated by the processing resource, and interrupting the processing resource when the comparison indicates that the processing resource has not processed the completed work unit indicated by the last interrupt request indicator.