proc_kpageflags(5)

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)