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    SubjectRe: perf stat output
    On Fri, Nov 13, 2009 at 06:07, Peter Zijlstra <peterz@infradead.org> wrote:
    > On Thu, 2009-11-12 at 20:03 -0200, Lucas De Marchi wrote:
    >> 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?
    >
    > No idea, you'd have to look at the code computing this M/sec stuff. I
    > think Ingo wrote that, so he might have an idea.

    But should it be, for example, L1-dcache-loads / seconds time elapsed,
    or does it have another meaning?



    Lucas De Marchi
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