Using /proc to get a process' current stack trace
FWIW, the equivalent in FreeBSD is &#x27;procstat -kk $PID&#x27;  Eg:<p><pre><code>  % procstat -kk 5592

  PID    TID COMM                TDNAME              KSTACK                   
 5592 103222 less                -                   </code></pre>
mi_switch+0xe1 sleepq_catch_signals+0x405 
sleepq_wait_sig+0xf _cv_wait_sig+0x154 tty_wait+0x1c 
ttydisc_read+0x1f2 ttydev_read+0x64 devfs_read_f+0xdc 
dofileread+0x95 sys_read+0xc3 amd64_syscall+0x369 
fast_syscall_common+0x101<p>procstat can also do interesting things, like show current rusage state:<p><pre><code>  % procstat -r 5592
  PID COMM             RESOURCE                          VALUE
 5592 less             user time                    00:00:00.010805
 5592 less             system time                  00:00:00.002444
 5592 less             maximum RSS                             3172 KB
 5592 less             integral shared memory                   192 KB
 5592 less             integral unshared data                    80 KB
 5592 less             integral unshared stack                  256 KB
 5592 less             page reclaims                            199
 5592 less             page faults                                0
 5592 less             swaps                                      0
 5592 less             block reads                                4
 5592 less             block writes                               0
 5592 less             messages sent                              0
 5592 less             messages received                          0
 5592 less             signals received                           0
 5592 less             voluntary context switches                59
 5592 less             involuntary context switches               0</code></pre>