The following is a demonstration of the syscallbypid.d script,

Here we run syscallbypid.d for a few seconds then hit Ctrl-C,

# syscallbypid.d

Tracing... Hit Ctrl-C to end.

^C

PID CMD SYSCALL COUNT

11039 dtrace setcontext 1

11039 dtrace lwp_sigmask 1

7 svc.startd portfs 1

357 poold lwp_cond_wait 1

27328 java_vm lwp_cond_wait 1

1532 Xorg writev 1

11039 dtrace lwp_park 1

11039 dtrace schedctl 1

11039 dtrace mmap 1

361 sendmail pollsys 1

11039 dtrace fstat64 1

11039 dtrace sigaction 2

11039 dtrace write 2

361 sendmail lwp_sigmask 2

1659 mozilla-bin yield 2

11039 dtrace sysconfig 3

361 sendmail pset 3

20317 sshd read 4

361 sendmail gtime 4

20317 sshd write 4

27328 java_vm ioctl 6

11039 dtrace brk 8

1532 Xorg setcontext 8

1532 Xorg lwp_sigmask 8

20317 sshd pollsys 8

357 poold pollsys 13

1659 mozilla-bin read 16

20317 sshd lwp_sigmask 16

1532 Xorg setitimer 17

27328 java_vm pollsys 18

1532 Xorg pollsys 19

11039 dtrace p_online 21

1532 Xorg read 22

1659 mozilla-bin write 25

1659 mozilla-bin lwp_park 26

11039 dtrace ioctl 36

1659 mozilla-bin pollsys 155

1659 mozilla-bin ioctl 306

In the above output, we can see that "mozilla-bin" with PID 1659 made the

most system calls - 306 ioctl()s.