University of Washington

Joseph Devietti

Luis Henrique Ceze

Mark Henry Oskin

Brandon Lucia

Daniel Joseph Grossman

Jacob Eric Nelson

Thomas Bergan

Devices and methods for providing deterministic execution of multithreaded applications are provided. In some embodiments, each thread is provided access to an isolated memory region, such as a private cache. In some embodiments, more than one private cache are synchronized via a modified MOESI coherence protocol. The modified coherence protocol may be configured to refrain from synchronizing the isolated memory regions until the end of an execution quantum. The execution quantum may end when all threads experience a quantum end event such as reaching a threshold instruction count, overflowing the isolated memory region, and/or attempting to access a lock released by a different thread in the same quantum.

Systems and methods for providing deterministic execution

A hardware and/or software facility for controlling the order of operations performed by threads of a multithreaded application on a multiprocessing system is provided. The facility may serialize or selectively-serialize execution of the multithreaded application such that, given the same input to the multithreaded application, the multiprocessing system deterministically interleaves operations, thereby producing the same output each time the multithreaded application is executed. The facility divides the execution of the multithreaded application code into two or more quantum specifying a deterministic number of operations, and the facility specifies a deterministic order in which the threads execute the two or more quantum. The deterministic number of operations may be adapted to follow the critical path of the multithreaded application. Specified memory operations may be executed regardless of the deterministic order, such as those accessing provably local data. The facility may provide dynamic bug avoidance and sharing of identified bug information.

Critical path deterministic execution of multithreaded applications in a transactional memory system

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Camarillo, CA, United States of America

Joseph Devietti