perf: Remove memory waste from fmt.Sprintf

sdk/trace/evictedqueue.go

@@ -29,6 +29,22 @@ func newEvictedQueue[T any](capacity int) evictedQueue[T] {
 	}
 }
 
+func newEvictedQueueEvent(capacity int) evictedQueue[Event] {
+	// Do not pre-allocate queue, do this lazily.
+	return evictedQueue[Event]{
+		capacity:   capacity,
+		logDropped: sync.OnceFunc(func() { global.Warn("limit reached: dropping trace trace.Event") }),
+	}
+}
+
+func newEvictedQueueLink(capacity int) evictedQueue[Link] {
+	// Do not pre-allocate queue, do this lazily.
+	return evictedQueue[Link]{
+		capacity:   capacity,
+		logDropped: sync.OnceFunc(func() { global.Warn("limit reached: dropping trace trace.Link") }),
+	}
+}
+
 // add adds value to the evictedQueue eq. If eq is at capacity, the oldest
 // queued value will be discarded and the drop count incremented.
 func (eq *evictedQueue[T]) add(value T) {

sdk/trace/trace_test.go

@@ -2107,3 +2107,16 @@ func TestAddLinkToNonRecordingSpan(t *testing.T) {
 		t.Errorf("AddLinkToNonRecordingSpan: -got +want %s", diff)
 	}
 }
+
+func BenchmarkTraceStart(b *testing.B) {
+	tracer := NewTracerProvider().Tracer("")
+	ctx := trace.ContextWithSpanContext(context.Background(), trace.SpanContext{})
+
+	b.ReportAllocs()
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		_, span := tracer.Start(ctx, "")
+		span.End()
+	}
+}

sdk/trace/tracer.go

@@ -132,8 +132,8 @@ func (tr *tracer) newRecordingSpan(psc, sc trace.SpanContext, name string, sr Sa
 		spanKind:    trace.ValidateSpanKind(config.SpanKind()),
 		name:        name,
 		startTime:   startTime,
-		events:      newEvictedQueue[Event](tr.provider.spanLimits.EventCountLimit),
-		links:       newEvictedQueue[Link](tr.provider.spanLimits.LinkCountLimit),
+		events:      newEvictedQueueEvent(tr.provider.spanLimits.EventCountLimit),
+		links:       newEvictedQueueLink(tr.provider.spanLimits.LinkCountLimit),
 		tracer:      tr,
 	}