cc-metric-collector/collectors/likwid/groups/interlagos/L3CACHE.txt
2021-03-25 14:47:10 +01:00

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SHORT L3 cache miss rate/ratio
EVENTSET
PMC0 RETIRED_INSTRUCTIONS
UPMC0 UNC_READ_REQ_TO_L3_ALL
UPMC1 UNC_L3_CACHE_MISS_ALL
UPMC2 UNC_L3_LATENCY_CYCLE_COUNT
UPMC3 UNC_L3_LATENCY_REQUEST_COUNT
METRICS
Runtime (RDTSC) [s] time
L3 request rate UPMC0/PMC0
L3 miss rate UPMC1/PMC0
L3 miss ratio UPMC1/UPMC0
L3 average access latency [cycles] UPMC2/UPMC3
LONG
Formulas:
L3 request rate = UNC_READ_REQ_TO_L3_ALL/INSTRUCTIONS_RETIRED
L3 miss rate = UNC_L3_CACHE_MISS_ALL/INSTRUCTIONS_RETIRED
L3 miss ratio = UNC_L3_CACHE_MISS_ALL/UNC_READ_REQ_TO_L3_ALL
L3 average access latency = UNC_L3_LATENCY_CYCLE_COUNT/UNC_L3_LATENCY_REQUEST_COUNT
-
This group measures the locality of your data accesses with regard to the L3
Cache. L3 request rate tells you how data intensive your code is or how many
data accesses you have on average per instruction. The L3 miss rate gives a
measure how often it was necessary to get cache lines from memory. And finally
L3 miss ratio tells you how many of your memory references required a cache line
to be loaded from a higher level. While the# data cache miss rate might be
given by your algorithm you should try to get data cache miss ratio as low as
possible by increasing your cache reuse. This group was inspired from the
whitepaper - Basic Performance Measurements for AMD Athlon 64, AMD Opteron and
AMD Phenom Processors - from Paul J. Drongowski.