Improved parallel architectural simulations on shared-memory multiprocessors

Processor self-scheduling in parallel discrete event simulation

“…The reason is the behavior of these types of simulati'ons. As has been observed in (Konas 1994, Soul6 1992, the most striking characteristic of architectural and logic-level simulations is the "clock" effect: peaks with considerable activity induced by the arrivals of the clock and of new input signals, followed by periods of diminishing activity as the signals propagate through the combinational elements of the simulatcd system. Thus, a scheduling queue implemented as a time-wheel that covers a simulated time interval equal to the clock period or to the propagation delay through a combinational circuit should be expected to achieve a constant O(1) access time.…”

“…In this way preference is given to locality management but load balancing is also taken into consideration. In synchronous PDES simulation, a logical process is activated when a new value arrives at its inputs and no event already exists in the input queue of the LP for that simulated time (Konas 1994). The activation of an LP results into its insertion in the scheduling queue of the processor that activated it.…”

“…A fourth simulation (nonuniform load) introduces nonuniformity in the computation requirements of the simulated components. In all simulations we pre-partition the system using both random (RND) and string-based (STR) partitioning methods (Konas 1994), and turn self-scheduling on (DYNamic) and off (STATic). The overhead introduced into the computation by the load balancing step is (most of) the difference between the static and dynamic versions of each simulator.…”

“…Synchronous PDES methods have shown significant potential in the parallel execution of such simulations (Konas 1994). On the other hand, asynchronous PDES methods (both conservative and optimistic) are less attractive due to the significant overheads they introducein attempting to find parallelism during a simulation (Konas and Yew 1991).…”

Parallel simulation of the IBM SP2 interconnection network

“…Interconnection networks have been identified as suitable candidates for parallel simulation, e.g., see Goli et al (1989), Konas and Yew (1994), Miguel et al (1995), Nicol (1988), Yu, Towsley and Heidelberger (1989) and the references therein. Previous papers on this subject have typically modeled the networks at an abstract level, or modeled very simple networks.…”