OS-aware tuning: improving instruction cache energy efficiency on system workloads

Low power has been considered as an important issue in instruction cache (I-cache) designs. Several studies have shown that the I-cache can be tuned to reduce power. These techniques, however, exclusively focus on user-level applications, even though there is evidence that many commercial and emerging workloads often involve heavy use of the operating system (OS). This study goes beyond previous work to explore the opportunities to design energy-efficient Icache for system workloads. Employing a full-system experimental framework and a wide range of workloads, we characterize user and OS I-cache accesses and motivate OSaware I-cache tuning to save power. We then present two techniques (OS-aware cache way lookup and OS-aware cache set drowsy mode) to reduce the dynamic and the static power consumption of I-cache. The proposed OS-aware cache way lookup reduces the number of parallel tag comparisons and data array read-outs for cache accesses to save dynamic Icache power in a given opera...

• Type: Conference
• Year: 2006
• Where: IPCCC
• Authors: Tao Li, Lizy K. John
• Keywords: Cache, Cache Way Lookup, IPCCC 2006, OS-aware Cache