Today's computer systems are more powerful than ever, but have become so complex that it is now difficult for programmers to produce high-performance software. Even slight changes in programs or differences in a user's system can cause dramatic slowdowns. Currently, there is no way to guarantee that a program will perform as well as it did during testing. This situation makes it extremely difficult to track down the sources of inefficiencies or repair them. The result is reduced power and computational efficiency on servers, and a degraded user experience on client platforms.
This research aims to deliver reliable performance on modern computer systems. By introducing randomness into the way a computer runs programs, a reliably performant system will significantly reduce the probability that any small change will have a large impact on performance. For instance, consider a cache miss caused by a conflict. With standard caches, repeated access to the same elements would always cause misses, degrading performance. In a randomized cache or with randomized object placement, it would be very unlikely for the same line to be repeatedly evicted. The investigators are designing and evaluating the use of both randomized algorithms in software and hardware, separately and in combination, to remedy the numerous sources of pathological behavior in modern systems. The result will enable performance-portable applications that are immune to unfortunate interactions with microprocessor components.
