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

22 lines
759 B
Plaintext

SHORT Pairing ratio
EVENTSET
PMC0 INSTRUCTIONS_EXECUTED
PMC1 INSTRUCTIONS_EXECUTED_V_PIPE
METRICS
Runtime (RDTSC) [s] time
V-pipe ratio PMC1/PMC0
Pairing ratio PMC1/(PMC0-PMC1)
LONG
Formulas:
V-pipe ratio = INSTRUCTIONS_EXECUTED_V_PIPE/INSTRUCTIONS_EXECUTED
Pairing ratio = INSTRUCTIONS_EXECUTED_V_PIPE/(INSTRUCTIONS_EXECUTED-INSTRUCTIONS_EXECUTED_V_PIPE)
-
Each hardware thread on the Xeon Phi can execute two instruction simultaneously,
one in the U-pipe and one in the V-pipe. But this is only possible if the
instructions can be paired. The instructions executed in paired fashion are counted
by the event INSTRUCTIONS_EXECUTED_V_PIPE. The event INSTRUCTIONS_EXECUTED increments
for each instruction, hence the maximal increase per cycle can be 2.