b8d93bed07
bench_tokio_runtime (behind the bench feature) measures the two things
build_runtime changes vs the #[tokio::main] defaults:
A) worker over-subscription — throughput + p50/p99 of an async+CPU workload
with many workers vs core-sized, run under taskset to model a CPU quota.
B) blocking-pool RSS blast radius — peak RSS flooding the blocking pool with
memory-heavy spawn_blocking tasks, default 512 vs bounded.
No Postgres needed. Lets us verify the runtime change empirically before/after.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JG5yYZ9s868mJwqT2Qz7ez