This paper presents work that we have done to improve scalability of the directory entry cache (dcache). We investigated scalability problems resulting from many cache lookups, global lock contention, a possibly non-optimal eviction policy, and cacheline bouncing due to global reference counters. This paper provides an overview of solutions we tried, such as fast path walking, utilizing the read-copy update mutual exclusion mechanism, and lazy updating of the LRU list of dentries. We conclude with performance results showing scalability improvements.

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