Optimizing latency of read transactions with metadata update in memory expansion devices

Abstract

A memory read response is received from a memory controller in response to a memory request and includes specific data and specific metadata attendant to the specific data retrieved with specific memory addresses in the device memory. The specific data and specific metadata are sent to a host device in a host-bound memory read response. In response to determining that a metadata update condition is satisfied, a number of actions are performed as follows. Specific modified metadata attendant to the specific data is determined. A MEMC-bound memory write request for metadata update is generated. The MEMC-bound memory write request is used to write the specific modified metadata attendant to the specific data in the device memory. The specific data and the specific modified metadata are stored in an entry of a temporary write buffer until the entry is invalidated by the corresponding metadata update write acknowledgement returned from the MEMC.