Parallel and distributed model checking in Eddy

Abstract

Abstract. Model checking of safety properties can be scaled up by pooling the CPU and memory resources of multiple computers. As compute clusters containing 100s of nodes, with each node realized using multicore (e.g., 2) CPUs will be widespread, a model checker based on the parallel (shared memory) and distributed (message passing) paradigms will more efficiently use the hardware resources. Such a model checker can be designed by having each node employ two shared memory threads that run on the (typically) two CPUs of a node, with one thread responsible for state generation, and the other for efficient communication, including (i) performing overlapped asynchronous message passing, and (ii) aggregating the states to be sent into larger chunks in order to improve communication network utilization. We present the design details of such a novel model checking architecture called Eddy. We describe the design rationale, details of how the threads interact and yield control, exchange messages, as well as detect termination. We have realized an instance of this architecture for the Murphi modeling language. Called Eddy Murphi, we report its performance over the number of nodes as well as communication parameters such as those controlling state aggregation. Nearly linear reduction of compute time with increasing number of nodes is observed. Our thread task partition is done in such a way that it is modular, easy to port across different modeling languages, and easy to tune across a variety of platforms.

Formal Analysis for Debugging and Performance Optimization of MPI

“…A complete list of publications from this award are [5,6,7] which have appeared, one special issue journal paper based on [6] under review by the journal STTT, one invited journal paper based on [5] under review by the journal Parallel Computing, a special issue of selected papers from the TV06 workshop [10] being guest-edited by the PI and accepted by the ENTCS journal.…”

“…Eddy_Murphi runs on MPICH as well as Microsoft CCS, and also proves to be a valuable benchmark example in our research. Its code, and a conference paper which appeared in SPIN 2006 [6], are downloadable from our website.…”

Industrial Strength Distributed Explicit State Model Checking

“…In the past decade, several distributed EMC (DEMC) tools have arose, e.g. Eddy [7], Divine [8], and PSpin [9]. Most experiments in the DEMC literature pertain to the speed up of DEMC over sequential EMC.…”

Distributed Dynamic Partial Order Reduction Based Verification of Threaded Software

“…They pointed out the idea of coalescing states into larger messages for better network utilization in the context of model checking. Eddy [15] extends the work and studies the parallel and distributed model checking under the multicore architecture. Kumar and Mercer [17] improve the load balancing method in parallel Murphi.…”

“…An exhaustive literature survey is beyond the scope of this paper. Quite a few distributed and parallel model checkers based on message passing have been developed for Murphi and SPIN [14,15,16,17,18]. Stern and Dill [14] developed a parallel Murphi which distributes states to multiple nodes for further exploration according th the state's signature.…”