Memory performance attacks: denial of memory service in multi-core systems

We are entering the multi-core era in computer science. All major high-performance processor manufacturers have inte-grated at least two cores (processors) on the same chip — and it is predicted that chips with many more cores will become wide-spread in the near future. As cores on the same chip share the DRAM memory system, multiple programs executing on dif-ferent cores can interfere with each others ’ memory access re-quests, thereby adversely affecting one another’s performance. In this paper, we demonstrate that current multi-core proces-sors are vulnerable to a new class of Denial of Service (DoS) attacks because the memory system is “unfairly ” shared among multiple cores. An application can maliciously destroy the memory-related performance of another application running on the same chip. We call such an application a memory perfor-mance hog (MPH). With the widespread deployment of multi-core systems in commodity desktop and laptop computers, we expect MPHs to become a prevalent security issue that could affect almost all computer users. We show that an MPH can reduce the performance of an-other application by 2.9 times in an existing dual-core system, without being significantly slowed down itself; and this prob-lem will become more severe as more cores are integrated on the same chip. Our analysis identifies the root causes of unfair-ness in the design of the memory system that make multi-core processors vulnerable to MPHs. As a solution to mitigate the performance impact of MPHs, we propose a new memory sys-tem architecture that provides fairness to different applications running on the same chip. Our evaluations show that this mem-ory system architecture is able to effectively contain the neg-ative performance impact of MPHs in not only dual-core but also 4-core and 8-core systems.