Improving TLB energy for java applications on JVM

Java platforms are widely deployed and used ranging from ultra-mobile embedded devices to servers for their portability and security. The TLB, a content addressable memory, can consume a significant power in these systems due to the nature of its associative search mechanism. In this paper, we propose and investigate three different optimizations for the TLB design, aiming to improve its power consumption for Java applications running on top of Java virtual machines. Our techniques exploit unique memory reference characteristics demonstrated by the JVM and its interaction with the Java applications running atop. Our first technique J-iTLB shows an average of 12.7% energy reduction in the iTLB with around 1% performance improvement for eliminating conflict misses between the JVM code and the Java application code. The second technique combines the J-iTLB with an object iTLB scheme and achieves an energy savings of 51% with a small 1% performance impact. Our third technique, a read-write partitioned J-dTLB, shows an average of 34% energy savings in the dTLB with 1% performance impact. Finally, when the J-iTLB with an object iTLB is combined with the J-dTLB, we obtained 42% overall TLB energy savings.