Verifies that the stack unwinder correctly captures deep call stacks. Every other scenario has shallow stacks (fewer than ~10 frames), so the unwinder's depth loop, its cycle-detection guard, and the frame cache under hundreds of repeated identical frames are otherwise untested.
The workload recurses 400 levels deep through recurse and then burns CPU in
burn at the leaf for the full duration.
- cpu-time: nearly all CPU is attributed to a stack of the form
<N frames omitted>;recurse;...;recurse;burn. The exporter keeps only the innermost ~64 frames and collapses the rest into a<N frames omitted>marker, so the marker's presence (plus the dozens of retained consecutiverecurseframes ending inburn) proves the sampler walked the full deep stack and counted the omitted frames.