title: Confusing perf stat results，What does it means about L1-dcache-loads 1110.763 M/sec? M is MB?
body: <pre><code>perf results:
      1501.634694 task-clock                #    1.835 CPUs utilized            ( +-  0.11% )
                     137 context-switches          #    0.000 M/sec                    ( +-  1.06% )
                       5 CPU-migrations            #    0.000 M/sec                    ( +-  7.14% )
                 145,306 page-faults               #    0.097 M/sec                    ( +-  0.00% )
           2,973,182,970 cycles                    #    1.980 GHz                      ( +-  0.09% ) [40.04%]
             379,990,837 stalled-cycles-frontend   #   12.78% frontend cycles idle     ( +-  0.79% ) [39.66%]
             230,979,839 stalled-cycles-backend    #    7.77% backend  cycles idle     ( +-  5.22% ) [39.88%]
           6,457,881,267 instructions              #    2.17  insns per cycle        
                                                   #    0.06  stalled cycles per insn  ( +-  0.76% ) [49.76%]
             318,376,775 branches                  #  212.020 M/sec                    ( +-  0.82% ) [49.62%]
                  47,093 branch-misses             #    0.01% of all branches          ( +- 10.27% ) [50.27%]
           1,667,960,311 L1-dcache-loads           # 1110.763 M/sec                    ( +-  0.54% ) [50.98%]
              11,817,899 L1-dcache-load-misses     #    0.71% of all L1-dcache hits    ( +-  1.16% ) [51.09%]
               1,408,419 LLC-loads                 #    0.938 M/sec                    ( +-  3.71% ) [41.25%]
                 950,688 LLC-load-misses           #   67.50% of all LL-cache hits     ( +-  8.25% ) [40.74%]
  
             0.818404313 seconds time elapsed                                          ( +-  0.29% )
  </code></pre>