[2025/04/26] The comment is no longer there.
Mach VM had (or still has if Mac OS X counts) an interesting detail in its VM scanner implementation (osfmk/vm/vm_page.h):
/*
* Each page entered on the inactive queue obtains a ticket from a
* particular ticket roll. Pages granted tickets from a particular
* roll generally flow through the queue as a group. In this way when a
* page with a ticket from a particular roll is pulled from the top of the
* queue it is extremely likely that the pages near the top will have tickets
* from the same or adjacent rolls. In this way the proximity to the top
* of the queue can be loosely ascertained by determining the identity of
* the roll the pages ticket came from.
*/