[Gems-users] How to identify cache hit rate in Ruby?

["Lei Yang" <lei.d.yang@xxxxxxxxx>]

Dear list,

I'm wondering whether Ruby provides such statistics like cache
hit/miss rate? For example, in the following stats report from Ruby:

L1D_cache cache stats:
 L1D_cache_total_misses: 29807
 L1D_cache_total_demand_misses: 29807
 L1D_cache_total_prefetches: 0
 L1D_cache_total_sw_prefetches: 0
 L1D_cache_total_hw_prefetches: 0
 L1D_cache_misses_per_transaction: 29807
 L1D_cache_misses_per_instruction: 0.000143247
 L1D_cache_instructions_per_misses: 6980.94

 L1D_cache_request_type_LD:   16.0197%
 L1D_cache_request_type_ST:   82.7557%
 L1D_cache_request_type_ATOMIC:   1.22454%

 L1D_cache_access_mode_type_SupervisorMode:   6933    23.2596%
 L1D_cache_access_mode_type_UserMode:   22874    76.7404%
 L1D_cache_request_size: [binsize: log2 max: 64 count: 29807 average:
4.90469 | standard deviation: 4.44371 | 0 642 88 23854 5077 0 0 146 ]

We know the total L1D cache misses, and the misses_per_instruction.
But do we know the total number of cache acesses, and thus the
hit/miss rate? Also, what does misses_per_transaction mean?

Thank you in advance!
Lei