tools/bitesize_example.txt

Examples of bitesize.py, the Linux bcc/eBPF version.


The aim of this tool is to show I/O distribution for requested block sizes, by process name.

# ./bitesize.py
Tracing... Hit Ctrl-C to end.
^C

Process Name = 'kworker/u128:1'
     Kbytes              : count     distribution
         0 -> 1          : 1        |********************                    |
         2 -> 3          : 0        |                                        |
         4 -> 7          : 2        |****************************************|

Process Name = 'bitesize.py'
     Kbytes              : count     distribution
         0 -> 1          : 0        |                                        |
         2 -> 3          : 0        |                                        |
         4 -> 7          : 0        |                                        |
         8 -> 15         : 0        |                                        |
        16 -> 31         : 0        |                                        |
        32 -> 63         : 0        |                                        |
        64 -> 127        : 0        |                                        |
       128 -> 255        : 1        |****************************************|

Process Name = 'dd'
     Kbytes              : count     distribution
         0 -> 1          : 3        |                                        |
         2 -> 3          : 0        |                                        |
         4 -> 7          : 6        |                                        |
         8 -> 15         : 0        |                                        |
        16 -> 31         : 1        |                                        |
        32 -> 63         : 1        |                                        |
        64 -> 127        : 0        |                                        |
       128 -> 255        : 0        |                                        |
       256 -> 511        : 1        |                                        |
       512 -> 1023       : 0        |                                        |
      1024 -> 2047       : 488      |****************************************|

Process Name = 'jbd2/dm-1-8'
     Kbytes              : count     distribution
         0 -> 1          : 0        |                                        |
         2 -> 3          : 0        |                                        |
         4 -> 7          : 1        |****************************************|

Process Name = 'cat'
     Kbytes              : count     distribution
         0 -> 1          : 1        |                                        |
         2 -> 3          : 0        |                                        |
         4 -> 7          : 0        |                                        |
         8 -> 15         : 0        |                                        |
        16 -> 31         : 0        |                                        |
        32 -> 63         : 1        |                                        |
        64 -> 127        : 0        |                                        |
       128 -> 255        : 0        |                                        |
       256 -> 511        : 1924     |****************************************|

Process Name = 'ntpd'
     Kbytes              : count     distribution
         0 -> 1          : 0        |                                        |
         2 -> 3          : 0        |                                        |
         4 -> 7          : 104      |****************************************|

Process Name = 'vmtoolsd'
     Kbytes              : count     distribution
         0 -> 1          : 0        |                                        |
         2 -> 3          : 0        |                                        |
         4 -> 7          : 1        |****************************************|

Process Name = 'bash'
     Kbytes              : count     distribution
         0 -> 1          : 0        |                                        |
         2 -> 3          : 0        |                                        |
         4 -> 7          : 0        |                                        |
         8 -> 15         : 0        |                                        |
        16 -> 31         : 2        |****************************************|

Process Name = 'jbd2/sdb-8'
     Kbytes              : count     distribution
         0 -> 1          : 0        |                                        |
         2 -> 3          : 0        |                                        |
         4 -> 7          : 1        |****************************************|
         8 -> 15         : 0        |                                        |
        16 -> 31         : 0        |                                        |
        32 -> 63         : 1        |****************************************|

We can see from above that there was a dd command being run which generated 488 IOPS between 1MB and 2MB, we can also see the
cat command generating 1924 IOPS between 256Kb and 512Kb.