NAME

       /proc/kpageflags - physical pages frame masks

DESCRIPTION

       /proc/kpageflags (since Linux 2.6.25)
              This  file  contains  64-bit masks corresponding to each physical page frame; it is
              indexed by page frame number (see the discussion of /proc/pid/pagemap).   The  bits
              are as follows:

                      0   -   KPF_LOCKED
                      1   -   KPF_ERROR
                      2   -   KPF_REFERENCED
                      3   -   KPF_UPTODATE
                      4   -   KPF_DIRTY
                      5   -   KPF_LRU
                      6   -   KPF_ACTIVE
                      7   -   KPF_SLAB
                      8   -   KPF_WRITEBACK
                      9   -   KPF_RECLAIM
                     10   -   KPF_BUDDY
                     11   -   KPF_MMAP            (since Linux 2.6.31)
                     12   -   KPF_ANON            (since Linux 2.6.31)
                     13   -   KPF_SWAPCACHE       (since Linux 2.6.31)
                     14   -   KPF_SWAPBACKED      (since Linux 2.6.31)
                     15   -   KPF_COMPOUND_HEAD   (since Linux 2.6.31)
                     16   -   KPF_COMPOUND_TAIL   (since Linux 2.6.31)
                     17   -   KPF_HUGE            (since Linux 2.6.31)
                     18   -   KPF_UNEVICTABLE     (since Linux 2.6.31)
                     19   -   KPF_HWPOISON        (since Linux 2.6.31)
                     20   -   KPF_NOPAGE          (since Linux 2.6.31)
                     21   -   KPF_KSM             (since Linux 2.6.32)
                     22   -   KPF_THP             (since Linux 3.4)
                     23   -   KPF_BALLOON         (since Linux 3.18)
                     24   -   KPF_ZERO_PAGE       (since Linux 4.0)
                     25   -   KPF_IDLE            (since Linux 4.3)
                     26   -   KPF_PGTABLE         (since Linux 4.18)

              For  further  details  on  the  meanings  of these bits, see the kernel source file
              Documentation/admin-guide/mm/pagemap.rst.   Before  Linux  2.6.29,   KPF_WRITEBACK,
              KPF_RECLAIM, KPF_BUDDY, and KPF_LOCKED did not report correctly.

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

SEE ALSO

       proc(5)