Enum thread_priority::unix::NormalThreadSchedulePolicy

pub enum NormalThreadSchedulePolicy {
    Idle,
    Batch,
    Other,
}

Normal (non-realtime) schedule policies For these schedule policies, niceness is used.

Variants

Idle

For running very low priority background jobs. (Since Linux 2.6.23.) SCHED_IDLE can be used only at static priority 0; the process nice value has no influence for this policy.

This policy is intended for running jobs at extremely low priority (lower even than a +19 nice value with the SCHED_OTHER or SCHED_BATCH policies).

Batch

For “batch” style execution of processes. (Since Linux 2.6.16.) SCHED_BATCH can be used only at static priority 0. This policy is similar to SCHED_OTHER in that it schedules the thread according to its dynamic priority (based on the nice value). The difference is that this policy will cause the scheduler to always assume that the thread is CPU-intensive. Consequently, the scheduler will apply a small scheduling penalty with respect to wakeup behavior, so that this thread is mildly disfavored in scheduling decisions.

This policy is useful for workloads that are noninteractive, but do not want to lower their nice value, and for workloads that want a deterministic scheduling policy without interactivity causing extra preemptions (between the workload’s tasks).

Other

The standard round-robin time-sharing policy, also sometimes referred to as “Normal”.

SCHED_OTHER can be used at only static priority 0 (i.e., threads under real-time policies always have priority over SCHED_OTHER processes). SCHED_OTHER is the standard Linux time-sharing scheduler that is intended for all threads that do not require the special real-time mechanisms.

The thread to run is chosen from the static priority 0 list based on a dynamic priority that is determined only inside this list. The dynamic priority is based on the nice value (see below) and is increased for each time quantum the thread is ready to run, but denied to run by the scheduler.

This ensures fair progress among all SCHED_OTHER threads.

In the Linux kernel source code, the SCHED_OTHER policy is actually named SCHED_NORMAL.

Trait Implementations

impl Clone for NormalThreadSchedulePolicy

fn clone(&self) -> NormalThreadSchedulePolicy

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for NormalThreadSchedulePolicy

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

Formats the value using the given formatter.

impl Hash for NormalThreadSchedulePolicy

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)where
    H: Hasher,
    Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for NormalThreadSchedulePolicy

fn cmp(&self, other: &NormalThreadSchedulePolicy) -> Ordering

This method returns an Ordering between self and other.

const fn max(self, other: Self) -> Selfwhere
    Self: Sized,

Compares and returns the maximum of two values.

const fn min(self, other: Self) -> Selfwhere
    Self: Sized,

Compares and returns the minimum of two values.

const fn clamp(self, min: Self, max: Self) -> Selfwhere
    Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval.

impl PartialEq<NormalThreadSchedulePolicy> for NormalThreadSchedulePolicy

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd<NormalThreadSchedulePolicy> for NormalThreadSchedulePolicy

fn partial_cmp(&self, other: &NormalThreadSchedulePolicy) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Copy for NormalThreadSchedulePolicy

impl Eq for NormalThreadSchedulePolicy

impl StructuralEq for NormalThreadSchedulePolicy

impl StructuralPartialEq for NormalThreadSchedulePolicy