[[https://perf.wiki.kernel.org/index.php/Main_Page|Site web]]

===Exécution===

  perf stat ./program

<code>
 Performance counter stats for './program':

            856,75 msec task-clock:u              #    0,999 CPUs utilized          
                 0      context-switches:u        #    0,000 K/sec                  
                 0      cpu-migrations:u          #    0,000 K/sec                  
               110      page-faults:u             #    0,128 K/sec                  
     2 995 631 212      cycles:u                  #    3,497 GHz                    
     1 434 273 421      stalled-cycles-frontend:u #   47,88% frontend cycles idle   
     4 802 352 286      instructions:u            #    1,60  insn per cycle         
                                                  #    0,30  stalled cycles per insn
     1 200 437 383      branches:u                # 1401,161 M/sec                  
            32 390      branch-misses:u           #    0,00% of all branches        

       0,857405569 seconds time elapsed

       0,857183000 seconds user
       0,000000000 seconds sys
</code>

  * ''branch-misses'' : c'est les échecs des prédictions de branches. [[http://www.bnikolic.co.uk/blog/hpc-perf-branchprediction.html|Measuring Branch Prediction Accuracy Using Linux Perf Tools]] {{ :prog:perf:b._nikolic_measuring_branch_prediction_accuracy_using_linux_perf_tools_2020-02-20_23_18_39_.html |Archive de 2013 le 20/02/2020}} [[https://stackoverflow.com/questions/11227809/why-is-processing-a-sorted-array-faster-than-processing-an-unsorted-array|Why is processing a sorted array faster than processing an unsorted array?]] {{ :prog:perf:java_-_why_is_processing_a_sorted_array_faster_than_processing_an_unsorted_array_-_stack_overflow_2020-02-20_23_19_47_.html |Archive du 27/06/2012 le 20/02/2020}}
  * ''stalled-cycles-frontend'' : le cache est mal utilisé.
  * ''stalled-cycles-backend'' : le CPU est en attente d'une ressource (mémoire, disque, …).