Enum linux_perf_event_reader::SamplingPolicy

pub enum SamplingPolicy {
    NoSampling,
    Period(NonZeroU64),
    Frequency(u64),
}

Sampling Policy

Events can be set to notify when a threshold is crossed, indicating an overflow. […]

Overflows are generated only by sampling events (sample_period must have a nonzero value).

Variants

NoSampling

NoSampling means that the event is a count and not a sampling event.

Period(NonZeroU64)

Sets a fixed sampling period for a sampling event, in the unit of the observed count / event.

A “sampling” event is one that generates an overflow notification every N events, where N is given by the sampling period. A sampling event has a sampling period greater than zero.

When an overflow occurs, requested data is recorded in the mmap buffer. The SampleFormat bitfield controls what data is recorded on each overflow.

Frequency(u64)

Sets a frequency for a sampling event, in “samples per (wall-clock) second”.

This uses a dynamic period which is adjusted by the kernel to hit the desired frequency. The rate of adjustment is a timer tick.

If SampleFormat::PERIOD is requested, the current period at the time of the sample is stored in the sample.

Trait Implementations

impl Clone for SamplingPolicy

fn clone(&self) -> SamplingPolicy

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for SamplingPolicy

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

Formats the value using the given formatter.

impl Copy for SamplingPolicy