/proc/kpageflags - physical pages frame masks
- /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.