#  dtrace -n syscall:::entry/pid==24250/'{@[probefunc] = count() }'
dtrace: description 'syscall:::entry' matched 230 probes
^C

  getpid                                                            1
  lwp_continue                                                      1
  lwp_create                                                        1
  lwp_kill                                                          1
  schedctl                                                          1
  setcontext                                                        1
  uucopy                                                            1
  lwp_sigmask                                                       2
  kill                                                              3
  pwrite                                                            3
  timer_settime                                                     4
  lwp_park                                                         13
  getmsg                                                           21
  ioctl                                                           181
  sigaction                                                      6545
  sigwait                                                        6548
  pollsys                                                       13111
  write                                                         13113
  read                                                          19648



dtrace -n 'syscall:::entry/ pid == 24250 && probefunc == "write" /{@[ustack()] = count(); }'
dtrace: description 'syscall:::entry' matched 230 probes
^C


              libc.so.1`__write+0xa
              qemu-system-x86_64`qemu_event_increment+0x2e
              qemu-system-x86_64`qemu_notify_event+0x18
              qemu-system-x86_64`qemu_set_fd_handler2+0x135
              qemu-system-x86_64`vnic_update_fd_handler+0x76
              qemu-system-x86_64`vnic_write_poll+0x28
              qemu-system-x86_64`vnic_writable+0x25
              qemu-system-x86_64`main_loop_wait+0x3d2
              qemu-system-x86_64`kvm_main_loop+0x119
              qemu-system-x86_64`main_loop+0x17
              qemu-system-x86_64`main+0x2d45
              qemu-system-x86_64`_start+0x6c
               44

              libc.so.1`__write+0xa
              qemu-system-x86_64`qemu_event_increment+0x2e
              qemu-system-x86_64`qemu_notify_event+0x18
              qemu-system-x86_64`qemu_set_fd_handler2+0x135
              qemu-system-x86_64`vnic_update_fd_handler+0x76
              qemu-system-x86_64`vnic_write_poll+0x28
              qemu-system-x86_64`vnic_read_packet+0x7c
              qemu-system-x86_64`vnic_send+0x34
              qemu-system-x86_64`main_loop_wait+0x30c
              qemu-system-x86_64`kvm_main_loop+0x119
              qemu-system-x86_64`main_loop+0x17
              qemu-system-x86_64`main+0x2d45
              qemu-system-x86_64`_start+0x6c
               45

              libc.so.1`__write+0xa
              qemu-system-x86_64`qemu_event_increment+0x2e
              qemu-system-x86_64`qemu_notify_event+0x18
              qemu-system-x86_64`host_alarm_handler+0x5e
              qemu-system-x86_64`sigfd_handler+0x115
              qemu-system-x86_64`main_loop_wait+0x30c
              qemu-system-x86_64`kvm_main_loop+0x119
              qemu-system-x86_64`main_loop+0x17
              qemu-system-x86_64`main+0x2d45
              qemu-system-x86_64`_start+0x6c
            19177

              libc.so.1`__write+0xa
              qemu-system-x86_64`sigwait_compat+0xd5
              libc.so.1`_thrp_setup+0x83
              libc.so.1`_lwp_start
            19180



# dtrace -n 'syscall:::entry/ pid == 24250 && probefunc == "read" /{@[ustack()] = count(); }'
dtrace: description 'syscall:::entry' matched 230 probes
^C


              libc.so.1`__read+0xa
              qemu-system-x86_64`posix_aio_read+0x4e
              qemu-system-x86_64`main_loop_wait+0x30c
              qemu-system-x86_64`kvm_main_loop+0x119
              qemu-system-x86_64`main_loop+0x17
              qemu-system-x86_64`main+0x2d45
              qemu-system-x86_64`_start+0x6c
                6

              libc.so.1`__read+0xa
              qemu-system-x86_64`qemu_event_read+0x35
              qemu-system-x86_64`main_loop_wait+0x30c
              qemu-system-x86_64`kvm_main_loop+0x119
              qemu-system-x86_64`main_loop+0x17
              qemu-system-x86_64`main+0x2d45
              qemu-system-x86_64`_start+0x6c
            13292

              libc.so.1`__read+0xa
              qemu-system-x86_64`sigfd_handler+0x39
              qemu-system-x86_64`main_loop_wait+0x30c
              qemu-system-x86_64`kvm_main_loop+0x119
              qemu-system-x86_64`main_loop+0x17
              qemu-system-x86_64`main+0x2d45
              qemu-system-x86_64`_start+0x6c
            26529