This metric shows how often the machine was stalled on L1, L2, and L3 caches. While cache hits are serviced much more quickly than hits in DRAM, they can still incur a significant performance penalty. This metric also includes coherence penalties for shared data.
A significant proportion of cycles are being spent on data fetches from caches. Check Memory Access analysis to see if accesses to L2 or L3 caches are problematic and consider applying the same performance tuning as you would for a cache-missing workload. This may include reducing the data working set size, improving data access locality, blocking or partitioning the working set to fit in the lower cache levels, or exploiting hardware prefetchers. Consider using software prefetchers, but note that they can interfere with normal loads, increase latency, and increase pressure on the memory system. This metric includes coherence penalties for shared data. Check Microarchitecture Exploration analysis to see if contested accesses or data sharing are indicated as likely issues.