Completion Routine of IRP sometimes in IRQL 2 sometimes IRQL 0

Question

Within a Thread in IRQL 0 the completion routine, triggered from an IRP, for a WskSendTo call is sometimes in IRQL 2 and sometimes in IRQL 0. This seems mighty strange to me. Does anyone know if this is normal behaviour?

Answer 1

This is normal behavior.

Completion Routines may be called directly in the call to the routine or from any other context.

See the MSDN for a description of IoCompletion routines.