Profile memory access

perf mem command can be used to profile memory access. I.e, perf mem record samples while perf mem report shows the results. By default, perf mem record will count both load and store operations, and -t option can be used to specify one of them (e.g, -t load). Check following example: 

  1. # perf mem record ./stream
  2. # perf mem report --stdio
  3. # To display the perf.data header info, please use --header/--header-only options.
  4. #
  5. #
  6. # Total Lost Samples: 0
  7. #
  8. # Samples: 4K of event 'cpu/mem-loads,ldlat=30/P'
  9. # Total weight : 203745
  10. # Sort order   : local_weight,mem,sym,dso,symbol_daddr,dso_daddr,snoop,tlb,locked
  11. #
  12. # Overhead       Samples  Local Weight  Memory access             Symbol                            Shared Object      Data Symbol             Data Object        Snoop         TLB access              Locked
  13. # ........  ............  ............  ........................  ................................  .................  ......................  .................  ............  ......................  ......
  14. #
  15.      9.03%           575  32            L1 or L1 hit              [.] main                          stream             [.] 0x00007ffcac77e3c8  [stack]            None          L1 or L2 hit            No
  16.      8.97%           554  33            L1 or L1 hit              [.] main                          stream             [.] 0x00007ffcac77e3c8  [stack]            None          L1 or L2 hit            No
  17.      7.19%           431  34            L1 or L1 hit              [.] main                          stream             [.] 0x00007ffcac77e3c8  [stack]            None          L1 or L2 hit            No
  18.      6.79%           395  35            L1 or L1 hit              [.] main                          stream             [.] 0x00007ffcac77e3c8  [stack]            None          L1 or L2 hit            No
  19.      5.35%           303  36            L1 or L1 hit              [.] main                          stream             [.] 0x00007ffcac77e3c8  [stack]            None          L1 or L2 hit            No
  20.      4.16%           229  37            L1 or L1 hit              [.] main                          stream             [.] 0x00007ffcac77e3c8  [stack]            None          L1 or L2 hit            No
  21.      3.71%           199  38            L1 or L1 hit              [.] main                          stream             [.] 0x00007ffcac77e3c8  [stack]            None          L1 or L2 hit            No
  22.      3.08%           153  41            L1 or L1 hit              [.] main                          stream             [.] 0x00007ffcac77e3c8  [stack]            None          L1 or L2 hit            No
  24. ......