A dynamic cache sub-block design to reduce false sharing
Murali Krishna Kadiyala, Laxmi Narayan Bhuyan · 2002
Parallel applications differ from significant bus traffic due to the transfer of shared data. Large block sizes exploit locality and decrease the effective memory access time. It also has a tendency to group data together even though only a part of it is needed by any one processor. This is known as the false sharing problem. This research presents a dynamic sub-block coherence protocol which minimizes false sharing by trying to dynamically locate the point of false reference. Sharing traffic is minimized by maintaining coherence on smaller blocks (sub-blocks) which are truly shared, whereas larger blocks are used as the basic units of transfer. Larger blocks exploit locality while coherence is maintained on sub-blocks which minimize bus traffic due to shared misses. The simulation results indicate that the dynamic sub-block protocol reduces the false sharing misses by 20 to 30 percent over the fixed sub-block scheme.