Patent ID: 10282294

Abstract:
A system and method for mitigating overhead for accessing metadata for a cache in a hybrid memory module are disclosed. The method includes: providing a hybrid memory module including a DRAM cache, a flash memory, and an SRAM for storing a metadata cache; obtaining a host address including a DRAM cache tag and a DRAM cache index; and obtaining a metadata address from the DRAM cache index, wherein the metadata address includes a metadata cache tag and a metadata cache index. The method further includes determining a metadata cache hit based on a presence of a matching metadata cache entry in the metadata cache stored in the SRAM; in a case of a metadata cache hit, obtaining a cached copy of data included in the DRAM cache and skipping access to metadata included in the DRAM cache; and returning the data obtained from the DRAM cache to a host computer. The SRAM may further store a Bloom filter, and a potential DRAM cache hit may be determined based on a result of a Bloom filter test. A cache controller of the hybrid memory module may disable the Bloom filter when a metadata cache hit ratio is higher than a threshold.