International Business Machines Corporation
Testing a data coherency algorithm

Abstract:

Methods testing a data coherency algorithm via a simulated multi-processor environment are provided, which include implementing: (i) a transactional footprint keeping the address of each cache line used by the processor core, (ii) a reference model operating on and keeping a set of timestamps for a cache line, the set including a construction date representing a global timestamp when new data arrives at a private cache hierarchy and an expiration date representing another global timestamp when a cross-invalidation hits the private cache hierarchy, (iii) a core observed timestamp representing a global timestamp of an oldest construction date of data used before, and (iv) interface events monitoring instruction sequences guaranteed by transactional execution to ensure atomicity of a transaction. Upon detecting a transaction end event and finding a cache line of the transactional footprint having an expiration date older than or equal to a core observed time, an error is reported.