Mitigating DRAM cache metadata access overhead with SRAM metadata cache and bloom filter

    公开(公告)号:US10282294B2

    公开(公告)日:2019-05-07

    申请号:US15587286

    申请日:2017-05-04

    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.

    HBM WITH IN-MEMORY CACHE MANAGER
    50.
    发明申请

    公开(公告)号:US20180032437A1

    公开(公告)日:2018-02-01

    申请号:US15272339

    申请日:2016-09-21

    Abstract: A system and method for using high bandwidth memory as cache memory. A high bandwidth memory may include a logic die, and, stacked on the logic die, a plurality of dynamic read-only memory dies. The logic die may include a cache manager, that may interface to external systems through an external interface conforming to the JESD235A standard, and that may include an address translator, a command translator, and a tag comparator. The address translator may translate each physical address received through the external interface into a tag value, a tag address in the stack of memory dies, and a data address in the stack of memory dies. The tag comparator may determine whether a cache hit or cache miss has occurred, according to whether the tag value generated by the address translator matches the tag value stored at the tag address.

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