Dual-layered file cache on cc-NUMA system

CC-NUMA is a widely adopted and deployed architecture of high performance computers. These machines are attractive for their transparent access to local and remote memory. However, the prohibitive latency gap between local and remote access deteriorates applications´ performance seriously due to memory access stalls. File system cache, especially, being shared by all processes, inevitably triggers many remote accesses. To address this problem, we suggest and implement a mechanism that uses local memory to cache remote file cache, of which the main purpose is to improve data locality. Using realistic workload on a two-node cc-NUMA machine, we show that the cost of such a mechanism is as low as 0.5%, the performance can be increased 14.3% at most, and the local hit ratio can be improved as much as 40%