Cache-based speculation of stores following synchronizing operations
AssigneeInternational Business Machines Corporation
InventorsGuy L. Guthrie, William J. Starke, Derek E. Williams
Life of this patent
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Abstract
A store request in enqueued in a store queue of a cache memory of the data processing system. The store request identifies a target memory block by a target address and specifies store data. While the store request and a barrier request older than the store request are enqueued in the store queue, a read-claim machine of the cache memory is dispatched to acquire coherence ownership of target memory block of the store request. After coherence ownership of the target memory block is acquired and the barrier request has been retired from the store queue, a cache array of the cache memory is updated with the store data.
Claims11
A cache memory, comprising:
- a cache array including storage for copies of memory blocks;
- a directory of contents of the cache array;
- a read-claim machine that performs requested accesses to the cache array;
- and
- a store queue including a plurality of entries and a store queue controller;
- wherein while a store request and a barrier request older than the store request are enqueued in the store queue, the store request identifying a target memory block by a target address and specifying store data, the read-claim machine acquires coherence ownership of the target memory block of the store request;
- and
- the cache memory, after coherence ownership of the target memory block is acquired and the barrier request has been retired from the store queue, updates the cache array with the store data.
Dependencies are inferred from the claim text.