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

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SHORT L3 cache miss rate/ratio
EVENTSET
FIXC0 INSTR_RETIRED_ANY
FIXC1 CPU_CLK_UNHALTED_CORE
FIXC2 CPU_CLK_UNHALTED_REF
PMC0:MATCH0=0x0081:MATCH1=0x3fffc0 OFFCORE_RESPONSE_0_OPTIONS
PMC1:MATCH0=0x0081:MATCH1=0x1 OFFCORE_RESPONSE_1_OPTIONS
PMC2 L1D_REPLACEMENT
METRICS
Runtime (RDTSC) [s] time
Runtime unhalted [s] FIXC1*inverseClock
Clock [MHz] 1.E-06*(FIXC1/FIXC2)/inverseClock
CPI FIXC1/FIXC0
L3 request rate PMC1/FIXC0
L3 miss rate PMC0/FIXC0
L3 miss ratio PMC0/PMC1
LONG
Formulas:
L3 request rate = OFFCORE_RESPONSE_1_OPTIONS:MATCH0=0x0081:MATCH1=0x1/INSTR_RETIRED_ANY
L3 miss rate = OFFCORE_RESPONSE_0_OPTIONS:MATCH0=0x0081:MATCH1=0x3fffc0/INSTR_RETIRED_ANY
L3 miss ratio = OFFCORE_RESPONSE_0_OPTIONS:MATCH0=0x0081:MATCH1=0x3fffc0/OFFCORE_RESPONSE_1_OPTIONS:MATCH0=0x0081:MATCH1=0x1
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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 L3 compared to all loaded cache lines in L1.
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.