set-mark-command-repeat-pop

set-mark-command-repeat-pop is a variable defined in `simple.el'.
Its value is

nil

Documentation:
Non-nil means repeating C-SPC after popping mark pops it again.
That means that C-u C-SPC C-SPC
will pop the mark twice, and
C-u C-SPC C-SPC C-SPC
will pop the mark three times.

A value of nil means C-SPC's behavior does not change
after C-u C-SPC.

You can customize this variable.