FM / lwtools

/usr/share/systemtap/examples/lwtools

Name	Size	Mode	Actions
accept2close-nd.8	1424	0644	edit dl rm
accept2close-nd.meta	597	0644	edit dl rm
accept2close-nd.stp	1798	0755	edit dl rm
accept2close-nd.txt	3385	0644	edit dl rm
biolatency-nd.8	1671	0644	edit dl rm
biolatency-nd.meta	622	0644	edit dl rm
biolatency-nd.stp	2071	0755	edit dl rm
biolatency-nd_example.txt	7362	0644	edit dl rm
bitesize-nd.8	1157	0644	edit dl rm
bitesize-nd.meta	491	0644	edit dl rm
bitesize-nd.stp	1543	0755	edit dl rm
bitesize-nd_example.txt	3426	0644	edit dl rm
execsnoop-nd.8	1235	0644	edit dl rm
execsnoop-nd.meta	570	0644	edit dl rm
execsnoop-nd.stp	1283	0755	edit dl rm
execsnoop-nd_example.txt	2585	0644	edit dl rm
fslatency-nd.8	1930	0644	edit dl rm
fslatency-nd.meta	660	0644	edit dl rm
fslatency-nd.stp	3982	0755	edit dl rm
fslatency-nd_example.txt	13384	0644	edit dl rm
fsslower-nd.8	1753	0644	edit dl rm
fsslower-nd.meta	623	0644	edit dl rm
fsslower-nd.stp	3715	0755	edit dl rm
fsslower-nd_example.txt	1938	0644	edit dl rm
killsnoop-nd.8	1131	0644	edit dl rm
killsnoop-nd.meta	384	0644	edit dl rm
killsnoop-nd.stp	1281	0755	edit dl rm
killsnoop-nd_example.txt	1908	0644	edit dl rm
opensnoop-nd.8	1268	0644	edit dl rm
opensnoop-nd.meta	357	0644	edit dl rm
opensnoop-nd.stp	1026	0755	edit dl rm
opensnoop-nd_example.txt	1124	0644	edit dl rm
README	107	0644	edit dl rm
rwtime-nd.8	1146	0644	edit dl rm
rwtime-nd.meta	412	0644	edit dl rm
rwtime-nd.stp	1599	0755	edit dl rm
rwtime-nd_example.txt	4185	0644	edit dl rm
syscallbypid-nd.8	1089	0644	edit dl rm
syscallbypid-nd.meta	404	0644	edit dl rm
syscallbypid-nd.stp	1100	0755	edit dl rm
syscallbypid-nd_example.txt	9322	0644	edit dl rm

Edit: /usr/share/systemtap/examples/lwtools/bitesize-nd_example.txt (3426B)

Examples of bitesize-nd.stp, the Linux SystemTap version.

This shows size distributions for requested block I/O, by process name:

# ./bitesize-nd.stp 
Tracing block I/O... Hit Ctrl-C to end.
^C
I/O size (bytes):

process name: flush-202:1
 value |-------------------------------------------------- count
  1024 |                                                    0
  2048 |                                                    0
  4096 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@                  33
  8192 |@@@@@@@@@@@@@@@@                                   16
 16384 |@@@@@@@@@                                           9
 32768 |@@@@                                                4
 65536 |@@@                                                 3
131072 |                                                    0
262144 |                                                    0

process name: kjournald
 value |-------------------------------------------------- count
  1024 |                                                     0
  2048 |                                                     0
  4096 |@                                                    4
  8192 |                                                     2
 16384 |                                                     2
 32768 |@                                                    7
 65536 |@                                                    5
131072 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@      182
262144 |                                                     0
524288 |                                                     0

process name: randread.pl
 value |-------------------------------------------------- count
  1024 |                                                      0
  2048 |                                                      0
  4096 |                                                      4
  8192 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@   1859
 16384 |                                                      0
 32768 |                                                      5
 65536 |                                                     18
131072 |                                                      0
262144 |                                                      0

process name: tar
 value |-------------------------------------------------- count
  1024 |                                                      0
  2048 |                                                      0
  4096 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@  1645
  8192 |@@@@@@@@@@@@@@@@@@@@@@@@@                           836
 16384 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@         1394
 32768 |@@@@@@@@@@@@@@@@                                    532
 65536 |@@@@@                                               180
131072 |@@@@@@                                              219
262144 |                                                      0
524288 |                                                      0

tar(1) was archiving a directory of varying sized files, and writing an output
file, which creates the distribution seen above.

The randread.pl program was performing 8 Kbyte random reads. Note that there
were a few larger I/O: some custom SystemTap can be used to explain this. Eg,
show kernel stack traces for I/O larger than 32 Kbytes. I'd guess it was
file system metadata.

The aim of this tool is to help characterize the disk I/O workload.

cmd: