The following is an example of the modcalls.d oneliner,
Here we run it for a few seconds then hit Ctrl-C,
# modcalls.d
dtrace: script './modcalls.d' matched 18437 probes
^C
ptm 2
mntfs 2
pool 2
kcf 4
pts 5
portfs 6
pset 6
ttcompat 9
ptem 9
devfs 13
ipf 15
namefs 20
ctfs 22
procfs 22
ldterm 23
ipgpc 48
sockfs 58
flowacct 69
ata 70
gld 75
rtls 76
specfs 83
ip 201
uhci 294
TS 333
tmpfs 694
doorfs 897
ufs 1329
uppc 5617
unix 49794
genunix 53445
The output lists kernel modules, and the number of function calls for
each module. For example, "rtls" - the network driver, called 76 functions.
This script may be useful to determine whether drivers are "thinking" when
troubleshooting driver issues.