for benchmarking, enable reports and flamegraphs

Cargo.toml

@@ -43,3 +43,9 @@ members = [
     "stress",
 ]
 exclude = ["examples/external-otlp-grpcio-async-std"]
+
+[profile.bench]
+# https://doc.rust-lang.org/cargo/reference/profiles.html#bench
+# See function names in profiling reports.
+# 2/true is too much, 0 is not enough, 1 is just right for back traces
+debug = 1

opentelemetry-sdk/Cargo.toml

@@ -37,7 +37,8 @@ rustdoc-args = ["--cfg", "docsrs"]
 
 [dev-dependencies]
 bincode = "1.2"
-criterion = "0.4.0"
+criterion = { version = "0.4.0", features = ["html_reports"] }
+pprof = { version = "0.11.1", features = ["flamegraph", "criterion"] }
 rand_distr = "0.4.0"
 crossbeam-queue = "0.3.1"
 

opentelemetry-sdk/benches/trace.rs

@@ -8,6 +8,7 @@ use opentelemetry_sdk::{
     export::trace::{ExportResult, SpanData, SpanExporter},
     trace as sdktrace,
 };
+use pprof::criterion::{Output, PProfProfiler};
 
 fn criterion_benchmark(c: &mut Criterion) {
     let mut group = c.benchmark_group("EvictedHashMap");
@@ -132,5 +133,9 @@ fn trace_benchmark_group<F: Fn(&sdktrace::Tracer)>(c: &mut Criterion, name: &str
     group.finish();
 }
 
-criterion_group!(benches, criterion_benchmark);
+criterion_group! {
+    name = benches;
+    config = Criterion::default().with_profiler(PProfProfiler::new(100, Output::Flamegraph(None)));
+    targets = criterion_benchmark
+}
 criterion_main!(benches);