Struct BrickProfiler 

pub struct BrickProfiler {
    pub run_id: String,
    pub traces: Vec<KernelTrace>,
    pub total_time_us: f64,
    pub diverged: bool,
    pub divergence_diagnosis: String,
}

BrickProfiler collects per-kernel traces for automated divergence detection.

Five-Whys Root Cause: Hours of manual “let me check X in Y” debugging → No automated tool identified which kernel diverged → BrickProfiler only captured timing, not checksums → Missing feature: per-kernel checksum capture → ROOT CAUSE: Brick Profiling lacked correctness instrumentation

Usage

use cbtop::{BrickProfiler, KernelTrace};

// CPU execution
let mut cpu_profiler = BrickProfiler::new("cpu_baseline");
cpu_profiler.add_trace(KernelTrace::new("rope_neox", 0, pos, "CPU")
    .with_input_checksum(&input)
    .with_output_checksum(&output));

// GPU execution
let mut gpu_profiler = BrickProfiler::new("cuda_test");
gpu_profiler.add_trace(KernelTrace::new("rope_neox", 0, pos, "CUDA")
    .with_input_checksum(&input)
    .with_output_checksum(&output));

// Automated divergence detection
let report = cpu_profiler.compare(&gpu_profiler);
if !report.matched {
    eprintln!("FIVE-WHYS ALERT: {}", report.diagnosis);
}

Fields

run_id: String

Run identifier (e.g., “cpu_baseline”, “cuda_test”)

traces: Vec<KernelTrace>

Collected kernel traces

total_time_us: f64

Total execution time in microseconds

diverged: bool

Whether any divergence was detected

divergence_diagnosis: String

Divergence diagnosis (if any)

Implementations

impl BrickProfiler

pub fn new(run_id: &str) -> Self

Create a new profiler for a run

pub fn add_trace(&mut self, trace: KernelTrace)

Add a kernel trace

pub fn is_diverged(&self) -> bool

Check if divergence was detected

pub fn compare(&self, reference: &BrickProfiler) -> DivergenceReport

Compare this profiler’s traces against a reference (e.g., CPU vs GPU)

Returns a DivergenceReport identifying the first divergent kernel. Matching is done by (kernel_name, layer_idx, position) triple.

pub fn compare_and_mark( &mut self, reference: &BrickProfiler, ) -> DivergenceReport

Compare and set internal divergence state

pub fn traces_for_kernel(&self, kernel_name: &str) -> Vec<&KernelTrace>

Get traces for a specific kernel name

pub fn traces_for_layer(&self, layer_idx: usize) -> Vec<&KernelTrace>

Get traces for a specific layer

pub fn clear(&mut self)

Clear all traces (for reuse)

pub fn to_json(&self) -> Result<String, Error>

Serialize to JSON for pmat brick-score consumption

pub fn from_json(json: &str) -> Result<Self, Error>

Deserialize from JSON

Trait Implementations

impl Clone for BrickProfiler

fn clone(&self) -> BrickProfiler

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BrickProfiler

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for BrickProfiler

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for BrickProfiler

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

where __S: Serializer,

Serialize this value into the given Serde serializer.