cc-metric-collector/collectors/likwid/groups/broadwell/L3CACHE.txt

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2021-03-25 14:47:10 +01:00
SHORT L3 cache miss rate/ratio
EVENTSET
FIXC0 INSTR_RETIRED_ANY
FIXC1 CPU_CLK_UNHALTED_CORE
FIXC2 CPU_CLK_UNHALTED_REF
PMC0 MEM_LOAD_UOPS_RETIRED_L3_ALL
PMC1 MEM_LOAD_UOPS_RETIRED_L3_MISS
PMC2 UOPS_RETIRED_ALL
METRICS
Runtime (RDTSC) [s] time
Runtime unhalted [s] FIXC1*inverseClock
Clock [MHz] 1.E-06*(FIXC1/FIXC2)/inverseClock
CPI FIXC1/FIXC0
L3 request rate PMC0/PMC2
L3 miss rate PMC1/PMC2
L3 miss ratio PMC1/PMC0
LONG
Formulas:
L3 request rate = MEM_LOAD_UOPS_RETIRED_L3_ALL/UOPS_RETIRED_ALL
L3 miss rate = MEM_LOAD_UOPS_RETIRED_L3_MISS/UOPS_RETIRED_ALL
L3 miss ratio = MEM_LOAD_UOPS_RETIRED_L3_MISS/MEM_LOAD_UOPS_RETIRED_L3_ALL
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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.