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MemoryAvailability

Struct MemoryAvailability 

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pub struct MemoryAvailability { /* private fields */ }
Expand description

Provenance-preserving memory availability for the current process.

Two quantities live here and they answer different questions.

  • Available (available_bytes) is free space right now: a finite cgroup-v1 or cgroup-v2 ceiling admits exactly min(host available, reclaim-aware cgroup available). A v2 literal memory.max = max remains typed as unbounded and therefore defers to the host; v1’s numeric unlimited sentinel participates exactly and likewise loses to a tighter host value. This quantity moves, and under pressure it goes to zero.
  • Capacity (capacity_bytes) is how much memory this process could ever address: min(host total, the binding cgroup's hard limit). It is a property of the box and the cgroup configuration, not of the schedule, so it does not move when a sibling allocates.

The distinction is load-bearing (#2684). “Does this dense footprint fit here at all?” is a capacity question and its answer must be stationary — see process_memory_availability on why a route derived from a moving quantity is a defect. “Does this allocation fit right now?” is an availability question, and the joint ledger (MemoryGovernor::try_reserve) is the instrument for it. Reading the second where the first was meant is what let a cgroup a few pages from its limit refuse a 28,800-byte design on a host with 448 GB free.

If an active controller cannot be parsed exactly, admission fails closed with zero bytes — both available and capacity — while retaining the typed probe failure; it never silently inherits host capacity.

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impl MemoryAvailability

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pub const fn host_available_bytes(&self) -> u64

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pub const fn host_total_bytes(&self) -> u64

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pub const fn capacity_bytes(&self) -> u64

The stationary ceiling on memory this process could ever address: min(host total, binding cgroup hard limit), or zero when the cgroup probe failed closed. Unlike Self::available_bytes this does not move when other work allocates, which is what makes it usable as a routing threshold (#2684).

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pub fn capacity_bytes_usize(&self) -> usize

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pub const fn cgroup(&self) -> &CgroupMemoryObservation

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pub const fn available_bytes(&self) -> u64

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pub fn available_bytes_usize(&self) -> usize

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pub const fn limiting_source(&self) -> MemoryAvailabilitySource

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impl Clone for MemoryAvailability

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fn clone(&self) -> MemoryAvailability

Returns a duplicate of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl Debug for MemoryAvailability

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

Formats the value using the given formatter. Read more
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impl Display for MemoryAvailability

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

Formats the value using the given formatter. Read more
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impl Eq for MemoryAvailability

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impl PartialEq for MemoryAvailability

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

Equality operator ==. Read more
1.0.0 (const: unstable) · Source§

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

Inequality operator !=. Read more
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impl StructuralPartialEq for MemoryAvailability

Auto Trait Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> CloneToUninit for T
where T: Clone,

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unsafe fn clone_to_uninit(&self, dest: *mut u8)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dest. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> IntoEither for T

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fn into_either(self, into_left: bool) -> Either<Self, Self>

Converts self into a Left variant of Either<Self, Self> if into_left is true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
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fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

Converts self into a Left variant of Either<Self, Self> if into_left(&self) returns true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
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impl<T> Pointable for T

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const ALIGN: usize

The alignment of pointer.
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type Init = T

The type for initializers.
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unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
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unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
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unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
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unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
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impl<T> Same for T

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type Output = T

Should always be Self
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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T> ToString for T
where T: Display + ?Sized,

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fn to_string(&self) -> String

Converts the given value to a String. Read more
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impl<T, U> TryFrom<U> for T
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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.