Shared Last-Level Caches and The Case for Longer Timeslices

Memory performance is important in modern systems. Contention at various levels in memory hierarchy can lead to significant application performance degradation due to interference. Further, modern, large, last-level caches (LLC) have fill times greater than the OS scheduling window. When several threads are running concurrently and timesharing the CPU cores, they may never be able to load their working sets into the cache before being rescheduled, thus permanently stuck in the "cold-start" regime. We show that by increasing the system scheduling timeslice length it is possible to amortize the cache cold-start penalty due to the multitasking and improve application performance by 10--15%.