COHERENCE PROCESSING WITH PRE-KILL MECHANISM TO AVOID DUPLICATED TRANSACTION IDENTIFIERS

An apparatus for processing coherency transactions in a computing system is disclosed. The apparatus may include a request queue circuit, a duplicate tag circuit, and a memory interface unit. The request queue circuit may be configured to generate a speculative read request dependent upon a received read transaction. The duplicate tag circuit may be configured to store copies of tag from one or more cache memories, and to generate a kill message in response to a determination that data requested in the received read transaction is stored in a cache memory. The memory interface unit may be configured to store the generated speculative read request dependent upon a stall condition. The stored speculative read request may be sent to a memory controller dependent upon the stall condition. The memory interface unit may be further configured to delete the speculative read request in response to the kill message.