/proc/kpagecount - count of mappings of physical pages

/proc/kpagecount (since Linux 2.6.25)

This file contains a 64-bit count of the number of times each physical page frame is mapped, indexed by page frame number (see the discussion of /proc/pid/pagemap).

The /proc/kpagecount file is present only if the CONFIG_PROC_PAGE_MONITOR kernel configuration option is enabled.

proc(5)