One or more message signaled interruption requests from one or more input/output (I/O) adapters are converted to I/O adapter event notifications. Each I/O adapter event notification includes the setting of one or more specific indicators in system memory and an interruption request, the first of which results in a pending I/O adapter interruption request. While a request for an I/O adapter interruption is pending, subsequent message signaled interruption requests are converted to I/O adapter event notifications, but do not result in additional requests for I/O adapter interruptions.