Specific Read Only Data Management for Memory Hierarchy Optimization

Gregory Vaumourin (1) , Dombek Thomas (1) , Guerre Alexandre (1) , Denis Barthou (2, 3)

1 LIST (CEA) - Laboratoire d'Intégration des Systèmes et des Technologies
2 LaBRI - Laboratoire Bordelais de Recherche en Informatique
3 RUNTIME - Efficient runtime systems for parallel architectures

The multiplication of the number of cores inside embedded systems has raised the pressure on the memory hierarchy. The cost of coherence protocol and the scalability problem of the memory hierarchy is nowadays a major issue. In this paper, a specific data management for read-only data is in-vestigated because these data can be duplicated in several memories without being tracked. Based on analysis of stan-dard benchmarks for embedded systems, we show that read-only data represent 62% of all the data used by applications and 18% of all the memory accesses. A specific data path for read-only data is then evaluated by using simulations. On the first level of the memory hierarchy, removing read-only data of the L1 cache and placing them in another read-only cache improve the data locality of the read-write data by 30% and decrease the total energy consumption of the first level memory by 5%.

Mots clés: read-only data; memory hierarchy; cache; data management

Domaines: Informatique [cs]

Gregory Vaumourin, Dombek Thomas, Guerre Alexandre, Denis Barthou. Specific Read Only Data Management for Memory Hierarchy Optimization. EWiLi 2014 - Workshop Embed With Linux, Nov 2014, Lisboa, Portugal. pp.Session 2. ⟨hal-01090218⟩