Struct PhaseSlice 

pub struct PhaseSlice {

    pub phase_epoch: u32,
    pub cpus_used: BTreeSet<usize>,
    pub wake_latencies_ns: Vec<u64>,
    pub wake_sample_total: u64,
    pub timer_latencies_ns: Vec<u64>,
    pub timer_sample_total: u64,
    pub run_delay_ns: u64,
    pub off_cpu_ns: u64,
    pub wall_ns: u64,
    pub migration_count: u64,
    pub iterations: u64,
    pub schedstat_cpu_time_ns: u64,
    pub numa_pages: BTreeMap<usize, u64>,
    pub vmstat_numa_pages_migrated: u64,
    pub max_gap_ms: u64,
    pub max_gap_cpu: usize,
    /* private fields */
}

Per-phase telemetry for one backdrop worker over one scenario step’s HOLD window [StepStart(k), StepEnd(k)). A backdrop worker spans every phase, so it accumulates a fresh slice between each parent-driven phase_epoch transition and finalizes it when the epoch moves (drain-on-change). Carries the per-phase subset of WorkerReport’s whole-run telemetry that has a host-side per-cgroup carrier (PhaseCgroupStats), so the host can pool slices across workers into per-epoch PhaseBuckets. Counter fields are per-phase deltas (end_snap − start_snap, re-baselined at each boundary); cpus_used and numa_pages are per-phase observations (gauges). Excludes iteration_costs_ns — that reservoir has no per-cgroup carrier at any level (it feeds only the run-level benchmark gate).

Fields

phase_epoch: u32

The 1-indexed phase this slice covers (scenario Step k → k+1; 0 = BASELINE, u32::MAX = inter-step gap). The host maps this to a PhaseBucket.step_index; gap- and baseline-tagged slices have no host bucket and are discarded.

cpus_used: BTreeSet<usize>

CPUs this worker ran on DURING this phase.

wake_latencies_ns: Vec<u64>

Per-wakeup latency samples (ns) recorded during this phase, reservoir-clamped to at most MAX_PHASE_WAKE_SAMPLES — a smaller cap than the whole-run MAX_WAKE_SAMPLES so a worker spanning many phases stays within the report pipe. The host re-caps the merged per-cgroup pool at the larger MAX_WAKE_SAMPLES.

wake_sample_total: u64

Total wake observations during this phase, INCLUDING any the reservoir dropped — the true population for unbiased cross-phase weighting.

timer_latencies_ns: Vec<u64>

Per-timer-cycle latency samples (ns) recorded during this phase by a crate::workload::WorkType::TimerLatency worker, reservoir-clamped to MAX_PHASE_WAKE_SAMPLES (like wake_latencies_ns). Distinct carrier so timer latency does not blur with wake latency.

timer_sample_total: u64

Total timer-cycle observations during this phase, INCLUDING any the reservoir dropped — the true population for unbiased cross-phase weighting. Mirrors wake_sample_total for timer_latencies_ns.

run_delay_ns: u64

/proc/self/schedstat run_delay (field 2) delta over this phase (ns).

off_cpu_ns: u64

Off-CPU time during this phase (ns): wall_ns − cpu_time over the phase. Paired with wall_ns so the host derives the off-CPU fraction and skips the not-measured wall_ns == 0 case rather than dividing by zero.

wall_ns: u64

Wall-clock duration of this phase as the worker observed it (ns) — the denominator for the off-CPU fraction. 0 for a phase the worker never ran in (not-measured).

migration_count: u64

CPU migrations observed during this phase.

iterations: u64

Outer-loop iterations during this phase.

schedstat_cpu_time_ns: u64

/proc/self/schedstat cpu_time (field 1, sum_exec_runtime) delta over this phase (ns).

numa_pages: BTreeMap<usize, u64>

Per-NUMA-node resident page counts observed at this phase’s end (/proc/self/numa_maps). A gauge, not a delta.

vmstat_numa_pages_migrated: u64

/proc/vmstat numa_pages_migrated delta over this phase (system-wide counter; host folds as MAX across workers).

max_gap_ms: u64

Longest checkpoint-to-checkpoint wall gap during this phase (ms).

max_gap_cpu: usize

CPU where this phase’s longest gap happened — coupled with max_gap_ms as an argmax pair (a bare max would desync the gap from its CPU).

Trait Implementations

impl Clone for PhaseSlice

fn clone(&self) -> PhaseSlice

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PhaseSlice

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

Formats the value using the given formatter.

impl Default for PhaseSlice

fn default() -> PhaseSlice

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for PhaseSlice

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for PhaseSlice

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

Tests for self and other values to be equal, and is used by ==.

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

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

impl Serialize for PhaseSlice

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for PhaseSlice

impl StructuralPartialEq for PhaseSlice