Kilo-instruction processors, runahead and prefetching

There is a continuous research effort devoted to overcome the memory wall problem. Prefetching is one of the most frequently used techniques. A prefetch mechanism anticipates the processor requests by moving data into the lower levels of the memory hierarchy. Runahead mechanism is another form of prefetching based on speculative execution. This mechanism executes speculative instructions under an L2 miss, preventing the processor from being stalled when the reorder buffer completely fills, and thus allowing the generation of useful prefetches. Another technique to alleviate the memory wall problem provides processors with large instruction windows, avoiding window stalls due to in-order commit and long latency loads. This approach, known as “Kilo-instruction processors”, relies on exploiting more instruction level parallelism allowing thousands of in-flight instructions while long latency loads are outstanding in memory. In this work, we present a comparative study of the three ab...

• Type: Conference
• Year: 2006
• Where: CF
• Authors: Tanausú Ramírez, Alex Pajuelo, Oliverio J. Santana, Mateo Valero
• Keywords: CF 2006, Long Latency Loads, Memory Wall Problem, Speculative Instructions