A data processing system includes a plurality of processors, each processor configured to execute instructions, including a message send instruction, and a message filtering unit. The message filtering system is configured to receive messages from one or more of the plurality of processors in response to execution of message send instructions, each message indicating a message type and a message payload. The message filtering unit is configured to determined, for each received message, a recipient processor indicated by the message payload. The message filtering system is further configured to, in response to receiving, within a predetermined interval of time, at least two messages having a same recipient processor and indicating a same message type, delivering a single interrupt request indicated by the same message type to the same recipient processor, wherein the single interrupt request is representative of the at least two messages.