Replacement policies for shared caches on symmetric multicores : a programmer-centric point of view

International audienceThe presence of shared caches in current multicore processors may generate a lot of performance variability in multiprogrammed environments. For applications with quality-of-service requirements, this performance variability may lead the programmer to be overly pessimistic about performance and reduce the application features and/or spend a lot of effort optimizing the algorithms. To solve this problem, there must be a way for the programmer to define a reasonable performance target and a guarantee that the actual performance is very unlikely to be below the targeted performance. We propose that the performance target be defined as the performance measured when each core runs a copy of the application, which we call self-performance. This study characterizes self-performance and explains how the shared-cache replacement policy can be modified for self-performance to be meaningful