Messages in this thread | | | From | Lucas De Marchi <> | Date | Thu, 12 Nov 2009 20:03:11 -0200 | Subject | perf stat output |
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Hi all!
Some questions about perf stat output. See example:
lucas@LMS-linux:~/programming/testprograms> perf stat -e L1-dcache-loads -e L1-dcache-load-misses -- make -j gcc test_schedchanges.c -o test_schedchanges gcc -pthread test_taskaff1.c -o test_taskaff1 gcc -pthread test_taskaff2.c -o test_taskaff2 gcc -pthread test_taskaff3.c -o test_taskaff3
Performance counter stats for 'make -j':
161384667 L1-dcache-loads # 0.000 M/sec 24853791 L1-dcache-load-misses # 0.000 M/sec
0.066893389 seconds time elapsed
Why do we have both L1-dcache-loads and L1-dcache-load-misses with 0.000 M/sec? Also, why do we have 0 M/s when running "perf stat -a -e cache-misses -e cache-references" but values different than 0 when running "perf stat -a" without selecting the events?
The last question: what does the "scaled from X%" mean? Is it related to the maximum number of performance registers a processor can count at a time?
Thanks
Lucas De Marchi
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