Managing Contention for Shared Resources on Multicore Processors Case Study - 1

Managing Contention for Shared Resources on Multicore Processors - Case Study Example As a result, they ran a group of applications on different schedules, paired differently such that each application had the opportunity to pair with the other applications. They ran each possible schedule in the same memory domain rather than as an individual entity. In doing this they managed to attain the actual degradation of each bench mark while sharing the same memory domain as another bench mark. They then compared the actual best schedule with the estimated best schedule, that is they compared the degradation of the estimated best schedule in relation to the actual best one. They concluded that high-rate-miss applications should not be combined with low-rate-miss applications. Zhuravlev et al.(2) adds that previous works meant to improve thread performance in multicore systems was based on cache contention as it was assumed that it was the main, if not the only cause of performance degradation. They also state that (Zhuravlev et al. 20) "in this context cache contention is suffering extra cache misses because its co-runner (threads running on cores that share the same LLC) bring their own data into the LLC evicting the data of others." As stated by (Federova et al. 45) when a thread requests a cache line that doesnt exist, then a cache miss is registered, and a new cache line must be allocated. Chandra, Guo, Kim and Salihin (nd, p1) indicate that the sharing of a cache by threads in multicore processors is important to prevent redundancy. However, when several threads share the same cache, they compete for the available cache space. The sharing of cache space isnt uniform and therefore, the performance of those threads that access less cache space is greatly reduced. Federova et al. (32) have throughout the analysis aim to prove that the best formula to avoid contention in multicore processor systems is by building a contention-aware scheduler. They state that assigning applications to cores depending on the best possible schedule, may