xref: /netbsd-src/external/cddl/dtracetoolkit/dist/Docs/Examples/bitesize_example.txt (revision c29d51755812ace2e87aeefdb06cb2b4dac7087a)
1In this example, bitesize.d was run for several seconds then Ctrl-C was hit.
2As bitesize.d runs it records how processes on the system are accessing the
3disks - in particular the size of the I/O operation. It is usually desirable
4for processes to be requesting large I/O operations rather than taking many
5small "bites".
6
7The final report highlights how processes performed. The find command mostly
8read 1K blocks while the tar command was reading large blocks - both as
9expected.
10
11   # bitesize.d
12   Tracing... Hit Ctrl-C to end.
13   ^C
14
15        PID  CMD
16       7110  -bash\0
17
18              value  ------------- Distribution ------------- count
19                512 |                                         0
20               1024 |@@@@@@@@@@@@@@@@@@@@@@@@@@               2
21               2048 |                                         0
22               4096 |@@@@@@@@@@@@@                            1
23               8192 |                                         0
24
25       7110  sync\0
26
27              value  ------------- Distribution ------------- count
28                512 |                                         0
29               1024 |@@@@@                                    1
30               2048 |@@@@@@@@@@                               2
31               4096 |                                         0
32               8192 |@@@@@@@@@@@@@@@@@@@@@@@@@                5
33              16384 |                                         0
34
35          0  sched\0
36
37              value  ------------- Distribution ------------- count
38               1024 |                                         0
39               2048 |@@@                                      1
40               4096 |                                         0
41               8192 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@     10
42              16384 |                                         0
43
44       7109  find /\0
45
46              value  ------------- Distribution ------------- count
47                512 |                                         0
48               1024 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@       1452
49               2048 |@@                                       91
50               4096 |                                         33
51               8192 |@@                                       97
52              16384 |                                         0
53
54          3  fsflush\0
55
56              value  ------------- Distribution ------------- count
57               4096 |                                         0
58               8192 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 449
59              16384 |                                         0
60
61       7108  tar cf /dev/null /\0
62
63              value  ------------- Distribution ------------- count
64                256 |                                         0
65                512 |                                         70
66               1024 |@@@@@@@@@@                               1306
67               2048 |@@@@                                     569
68               4096 |@@@@@@@@@                                1286
69               8192 |@@@@@@@@@@                               1403
70              16384 |@                                        190
71              32768 |@@@                                      396
72              65536 |                                         0
73
74
75