Hacking with walking a process tree with pstree

pstree is a small, command line (i.e., all-text mode) program
that displays the processes (i.e., executing instances of programs)
on the system in the form of a tree diagram. It differs from the
much more commonly used (and more complex) ps program in a number
of respects, including that the latter shows the processes in a list
rather than a tree diagram but provides more detailed information
about them.

source : http://www.linfo.org/pstree.html

$pstree -a -p 2658
chromium,2658
  ├─{Chrome_ChildIOT},2661
  ├─{CompositorRaste},2665
  ├─{Compositor},2664
  ├─{HTMLParserThrea},2666
  ├─{OptimizingCompi},2662
  └─{v8:SweeperThrea},2663
$pstree -a -p 1585
gnome-terminal-,1585
  ├─bash,1590
  │   └─pstree,2884 -a -p 1585
  ├─bash,2847
  │   └─top,2855
  ├─gnome-pty-helpe,1589
  ├─{dconf worker},1587
  ├─{gdbus},1586
  └─{gmain},1591
$pstree -a -p 28
(kworker/0:1,28)
$pstree -a -p 27
(kworker/1:1,27)
$pstree -a -p 2855
top,2855