PSSt (short for PSS tree) is a simple utility that shows memory usage for every process as well as their children, taking shared memory into account. You can think of it as ncdu for processes.

tmpfs file systems, unreclaimable SLAB caches, ZFS ARC, amdgpu VRAM spillover, and zram devices are also reported.

Sample output:

     PSS    ∑ PSS    PID command or mount point
  159.0k    12.8G      1 init [3]
    5.5M     7.0G  19645 ├ urxvt
    1.4M     7.0G  19646 │ └ bash
    1.0G     7.0G  19649 │   └ /opt/firefox/firefox-bin --name firefox-bin
  860.5M   860.5M  19937 │     ├ /opt/firefox/firefox-bin ...
  859.4M   859.4M  19817 │     ├ /opt/firefox/firefox-bin ...
    ...      ...    ...  │     ├ (...skipped for brevity...)
    7.4M     7.4M  20137 │     └ /opt/firefox/firefox-bin ...
    1.0G     1.0G  tmpfs ├ /dev/shm
    ...      ...    ...  ├ ...

Use -q to use less accurate estimates (useful for systems with large number of processes).