Struct PsiHalf 

#[non_exhaustive]
pub struct PsiHalf {
    pub avg10: u16,
    pub avg60: u16,
    pub avg300: u16,
    pub total_usec: u64,
}

One Pressure Stall Information half-line: either the some or full row for one resource. Mirrors the kernel emission format %s avg10=%lu.%02lu avg60=%lu.%02lu avg300=%lu.%02lu total=%llu in psi_show() (kernel/sched/psi.c).

avg10/60/300 are stored as centi-percent (lossless fixed-point) — the kernel writes LOAD_INT(avg).LOAD_FRAC(avg) as a 2-decimal-digit percentage in psi_show(). The integer expansion is int * 100 + frac, giving a numerical range of 0..=10099. The upper bound is 100.99 (not 100.00) because the kernel’s EWMA helper calc_load() (include/linux/sched/loadavg.h) rounds via newload += FIXED_1 - 1 before the final >> FSHIFT, so a fully-loaded group can land just over 100.0 for one sample. This avoids serde JSON float-roundtrip drift that would manifest as spurious non-zero deltas in compare output.

total_usec is microseconds (kernel div_u64(total_ns, NSEC_PER_USEC) in psi_show()). Same unit as CgroupCpuStats::usage_usec, so the existing auto_scale “µs” ladder applies.

“some” semantics: at least one task is stalled on this resource. “full” semantics: every runnable task is stalled. At the SYSTEM level (/proc/pressure/cpu), cpu.full is always zero by kernel design — the explicit gate if (!(group == &psi_system && res == PSI_CPU && full)) in psi_show() (kernel/sched/psi.c) skips the avg/total computation, but the seq_printf in psi_show() still emits the structurally-present line. Per-cgroup cpu.full (under <cgroup>/cpu.pressure) IS meaningful and computed normally. irq is full-only (kernel only_full = res == PSI_IRQ in psi_show()), so PsiResource::some for irq always reads zero.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

avg10: u16

10-second running average of pressure %, scaled by 100 (so 0..=10099 covers 0.00..=100.99 — see the EWMA-rounding note on the struct doc).

avg60: u16

60-second running average of pressure %, same scaling.

avg300: u16

300-second running average of pressure %, same scaling.

total_usec: u64

Cumulative total stalled time in microseconds.

Implementations

impl PsiHalf

pub fn avg10_percent(&self) -> f64

Convert the centi-percent avg10 value to a percentage f64. Returns 0.0..=100.99 per the kernel’s EWMA rounding (see struct-level doc).

pub fn avg60_percent(&self) -> f64

Convert the centi-percent avg60 value to a percentage f64. Same range as Self::avg10_percent.

pub fn avg300_percent(&self) -> f64

Convert the centi-percent avg300 value to a percentage f64. Same range as Self::avg10_percent.

Trait Implementations

impl Clone for PsiHalf

fn clone(&self) -> PsiHalf

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PsiHalf

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

Formats the value using the given formatter.

impl Default for PsiHalf

fn default() -> PsiHalf

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for PsiHalf

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for PsiHalf

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Copy for PsiHalf