Enum PageSizePolicy 

pub enum PageSizePolicy {
    Base,
    Transparent {
        order: PageOrder,
    },
    ExplicitHuge {
        order: PageOrder,
    },
}

Variants

Base

Transparent

A normal anonymous mapping that may materialize a PMD-sized leaf after MADV_HUGEPAGE. Allocation failure may fall back to the faulting base page, matching Linux’s VM_FAULT_FALLBACK contract.

Fields

order: PageOrder

ExplicitHuge

An explicit MAP_HUGETLB mapping. Failure is reported to userspace; silently changing its page size would violate the requested ABI.

Fields

order: PageOrder

Implementations

impl PageSizePolicy

pub const TRANSPARENT_2M: Self

pub const fn for_size(size: usize) -> Self

Derive an explicit materialization policy from a validated backend page size. Unsupported or non-power-of-two sizes conservatively use base pages; the syscall/backend boundary remains responsible for rejecting an invalid mapping request.

pub fn fault_leaf_size( self, advice: HugePageAdvice, mode: TransparentHugePageMode, ) -> Option<usize>

Selects the preferred leaf for one fault after applying Linux’s VMA and process-wide THP controls. Starry runs anonymous THP in madvise mode: default and MADV_NOHUGEPAGE use base pages, while MADV_HUGEPAGE may use the group’s PMD order unless the MM is completely disabled.

pub const fn permits_fault_fallback(self) -> bool

Trait Implementations

impl Clone for PageSizePolicy

fn clone(&self) -> PageSizePolicy

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for PageSizePolicy

impl Debug for PageSizePolicy

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for PageSizePolicy

fn default() -> PageSizePolicy

Returns the “default value” for a type.

impl Eq for PageSizePolicy

impl PartialEq for PageSizePolicy

fn eq(&self, other: &PageSizePolicy) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for PageSizePolicy