Cherry-MP: correctly integrating checkpointed early resource recycling in chip multiprocessors

Checkpointed early resource recycling (Cherry) is a recently-proposed microarchitectural technique that aims at improving critical resource utilization by performing aggressive resource recycling decoupled from instruction retirement, using a checkpoint/rollback mechanism to recover from occasional incorrect execution. In this paper, we explore correctness and performance issues that arise when Cherry-enabled processors are used in chip multiprocessor architectures. We propose mechanisms to address cache coherence, memory consistency, and forward progress issues in such environments. We also provide quantitative insight on the performance impact of the Cherry mechanism on parallel processing.