Locked cache line sharing
OwnerSimon Steely, Stephen Van Doreninventors
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Abstract
A technique to share cache lines among a plurality of bus agents. Embodiments of the invention comprise at least one technique to allow a number of agents, such as a processor or software program being executed by a processor, within a computer system or computer network to access a locked (“owned”) cache line, under certain circumstances, without incurring as much of the operational overhead and resulting performance degradation of many prior art techniques.
Claims30
A method comprising:
- placing a cache line into a locked state in which the cache line may be accessed among at least one other bus agent;
- providing an uncached version of the cache line to the at least one other bus agent;
- indicating to the at least one other bus agent whether the cache line has been modified.
An apparatus comprising:
- a cache line description buffer corresponding to a first bus agent to own the corresponding cache line, the cache line description buffer including an entry to indicate that the corresponding cache line is locked but may be accessed by other bus agents as uncached data.
A system comprising:
- a first bus agent to own a cache line;
- a second bus agent to access an uncached version of the cache line without changing the state of the cache line.
A machine-readable medium having stored thereon a set of instructions, which if executed by a machine cause the machine to perform a method comprising:
- performing a loop of operations;
- reading an uncached version of a cache line during at least one iteration of the loop of operations;
- performing an operation with an updated version of the uncached version if a write to the cache line occurs.
Dependencies are inferred from the claim text.