CONFIG_DEMAND_PAGING_PAGE_FRAMES_RESERVE

Number of page frames reserved for paging

Type: int

Help

This sets the number of page frames that will be reserved for
paging that do not count towards free memory. This is to
ensure that there are some page frames available for paging
code and data. Otherwise, it would be possible to exhaust
all page frames via anonymous memory mappings.

Direct dependencies

BOARD_QEMU_X86_TINY || (DEMAND_PAGING && MMU)

(Includes any dependencies from ifs and menus.)

Defaults

6 if NEWLIB_LIBC
32 if !LINKER_GENERIC_SECTIONS_PRESENT_AT_BOOT
0

Kconfig definitions

At <Zephyr>/boards/x86/qemu_x86/Kconfig.defconfig:107

Included via <Zephyr>/Kconfig:8 → <Zephyr>/Kconfig.zephyr:22

Menu path: (Top)

config DEMAND_PAGING_PAGE_FRAMES_RESERVE
    int
    default 6 if NEWLIB_LIBC
    depends on BOARD_QEMU_X86_TINY

At <Zephyr>/arch/Kconfig:705

Included via <Zephyr>/Kconfig:8 → <Zephyr>/Kconfig.zephyr:39

Menu path: (Top) → Enable MMU features → Enable demand paging [EXPERIMENTAL]

config DEMAND_PAGING_PAGE_FRAMES_RESERVE
    int "Number of page frames reserved for paging"
    default 32 if !LINKER_GENERIC_SECTIONS_PRESENT_AT_BOOT
    default 0
    depends on DEMAND_PAGING && MMU
    help
      This sets the number of page frames that will be reserved for
      paging that do not count towards free memory. This is to
      ensure that there are some page frames available for paging
      code and data. Otherwise, it would be possible to exhaust
      all page frames via anonymous memory mappings.

(The ‘depends on’ condition includes propagated dependencies from ifs and menus.)