1Demonstrations of bitehist.py, the Linux eBPF/bcc version.
2
3This prints a power-of-2 histogram to show the block I/O size distribution.
4A summary is printed after Ctrl-C is hit.
5
6# ./bitehist.py
7Tracing... Hit Ctrl-C to end.
8^C
9     kbytes          : count     distribution
10       0 -> 1        : 3        |                                      |
11       2 -> 3        : 0        |                                      |
12       4 -> 7        : 211      |**********                            |
13       8 -> 15       : 0        |                                      |
14      16 -> 31       : 0        |                                      |
15      32 -> 63       : 0        |                                      |
16      64 -> 127      : 1        |                                      |
17     128 -> 255      : 800      |**************************************|
18
19This output shows a bimodal distribution. The largest mod of 800 I/O were
20between 128 and 255 Kbytes in size, and another mode of 211 I/O were between
214 and 7 Kbytes in size.
22
23Understanding this distribution is useful for characterizing workloads and
24understanding performance. The existence of this distribution is not visible
25from averages alone.
26