proc_kpageflags - Man Page

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)

Info

2023-08-15 Linux man-pages 6.7