SKILL.md
DOCA Bench (doca_bench)
Where to start: This is a tool skill for invoking docabench, the cross-library micro-benchmark harness. Open [TASKS.md](TASKS.md) and start at [## configure](TASKS.md#configure) for the three-axis decision (target library × workload shape × measurement axis), then [## run](TASKS.md#run) for the smoke-before-bulk flow. Open [CAPABILITIES.md](CAPABILITIES.md) when the question is what docabench can measure, which DOCA libraries it can drive, or how to interpret throughput / latency / op-rate output without fooling yourself on warm-up or steady-state. If DOCA is not installed yet, route to [doca-setup](../../doca-setup/SKILL.md) first; if the install version is < 2.7.0, doca_bench is not shipped on this host.
Example questions this skill answers well
The CLASSES of doca_bench questions this skill is built to answer, each with one worked example. The class is the load-bearing piece; the worked example is one instance.
- "What does this DOCA library actually deliver on this device?" —
worked example: "throughput of DOCA Compress on my BlueField-3". Answered by the three-axis configuration in [CAPABILITIES.md ## Capabilities and modes](CAPABILITIES.md#capabilities-and-modes) + the smoke-before-bulk flow in [TASKS.md ## run](TASKS.md#run). The same shape answers "send-side throughput of DOCA RDMA" — doca_bench is cross-library, not single-library.
- **"Which DOCA libraries can
doca_benchactually drive on this
install?"** — worked example: "is doca_sha enumerable on a granular-build install". Answered by the built-in query system surfaced in [CAPABILITIES.md ## Capabilities and modes](CAPABILITIES.md#capabilities-and-modes) + [TASKS.md ## configure](TASKS.md#configure) step 2 (probe-before-bench). Empty enumeration = library not installed, not bench failure.
- "Is this number reliable, or did I miss the warm-up?" —
worked example: "why does my first-second number differ from my steady-state number". Answered by the measurement-soundness overlay in [CAPABILITIES.md ## Error taxonomy](CAPABILITIES.md#error-taxonomy) layer 5 + [TASKS.md ## test](TASKS.md#test) (the eval-loop overlay treats warm-up / steady-state / outliers as re-iteration triggers, not one-shot facts).
- **"Bench reports zero throughput / hangs at start / disagrees
with the public docs."** — worked example: "docabench shows zero ops for AES-GCM but docacaps says the device supports it". Answered by the layered error taxonomy in [CAPABILITIES.md ## Error taxonomy](CAPABILITIES.md#error-taxonomy) (config-syntax → device-binding → library-precondition → workload-precondition → measurement-soundness → version → cross-cutting) + [TASKS.md ## debug](TASKS.md#debug).
- **"How do I capture a baseline I can later regression-test
against?"** — worked example: "snapshot decompress throughput on this BlueField + DOCA version before a firmware update". Answered by the CSV output + version-overlay rule in [TASKS.md ## test](TASKS.md#test) (capture command line + version + device + as-deployed environment alongside the numbers; quoting numbers without the four-tuple is the cross-version regression-hunt failure mode).
- **"
doca_benchreturns nothing for library X — what does that
mean?"** — worked example: "empty output for DOCA SHA". Answered by the empty-output interpretation rules in [TASKS.md ## debug](TASKS.md#debug) + [CAPABILITIES.md ## Error taxonomy](CAPABILITIES.md#error-taxonomy). Re-route through [doca-caps](../doca-caps/SKILL.md) for the coarse per-device per-library capability ground truth, then back into bench once the capability is confirmed present.
Audience
This skill serves external operators, developers, and AI agents who need a reproducible, vendor-supported way to measure DOCA library performance on the user's actual install and device. Concretely:
- An external developer choosing between DOCA libraries (e.g.
COMPRESS vs SHA vs DMA throughput) before committing an application design.
- A platform operator validating a tuning change (NUMA pinning,
driver upgrade, firmware burn) by re-running a captured doca_bench baseline against the new state.
- An SRE / performance engineer producing a *"this is what the
device delivers today"* artifact that downstream consumers (capacity planning, regression bisection) can cite.
- An AI agent answering *"what throughput / latency should I
expect from DOCA library X on device Y?"* honestly — with a measured number, the command line that produced it, and the version + device + environment that scopes it — instead of guessing from datasheet headlines.
It is not for users debugging the doca_bench source code, and not a substitute for the live public DOCA Bench guide on docs.nvidia.com.
doca_bench is shipped as a tool (a single CLI binary plus a companion app for the remote half of remote-memory / RDMA / Eth scenarios), not a library you link against. The skill uses the same kind: tool three-file shape as the rest of the bundle so the agent's task-verb contract (configure / build / modify / run / test / debug) is uniform across libraries, services, and tools — even when individual verbs collapse to a routing stub for a shipped binary.
When to load this skill
Load this skill when the user is — or the agent needs to — invoke doca_bench on a real host with DOCA ≥ 2.7.0 installed (or inside the public NGC DOCA container with the equivalent version) to measure performance of a DOCA library. Concretely:
- Picking which DOCA library to benchmark for a candidate
workload (RDMA vs COMPRESS vs DMA, etc.).
- Picking which measurement axis to ask for (throughput vs bulk
latency vs precision latency vs max-bandwidth) — the four modes defined in tools/bench/doca_bench/configuration.hpp are not interchangeable.
- Probing the install's granular-build state so the agent can
honestly report "this library is not exposed on this install" instead of inventing a workload.
- Capturing a documented baseline (command line + version + device
+ as-deployed environment + numbers) for later regression hunts.
- Requiring the workload owner to predeclare acceptable variance
and obtaining two consecutive runs within that tolerance before reporting a stable result; otherwise escalating the variance.
- Diagnosing why a bench run reported zero / unstable / unexpected
results (the error-taxonomy walk in [TASKS.md ## debug](TASKS.md#debug)).
Do not load this skill for general DOCA orientation, library API work, or installation. For those, use [doca-public-knowledge-map](../../doca-public-knowledge-map/SKILL.md), the matching libs/<library> skill, or [doca-setup](../../doca-setup/SKILL.md). Do not load it for application-level end-to-end benchmarking either — doca_bench measures the DOCA library surface, not the user's application above it.
What this skill provides
This is a thin loader. Substantive material lives in two companion files:
CAPABILITIES.md— whatdoca_benchcan measure (the
cross-library scope, the three-axis configuration model, the documented operating modes, the warm-up / pipeline / multi-core concepts that constrain measurement soundness), the version overlay (doca-bench-specific facts on top of the canonical doca-version rules), the layered error taxonomy (config-syntax / device-binding / library-precondition / workload-precondition / measurement-soundness / version / cross-cutting), the observability surface (screen + CSV output, real-time stats, query system), and the safety posture (the public guide's "not for production" warning, the host vs BlueField execution rule, the companion-app attack surface).
TASKS.md— step-by-step workflows for the in-scope task
verbs: configure (the three-axis decision + the probe-before-bench step), build (route to install — the binary is shipped, the companion app is shipped), modify (refuse — do not patch the bench binary; modify the bench invocation instead), run (the smoke-before-bulk flow), test (the eval loop — warm-up, steady-state, outliers, cross-version), debug (walk the error taxonomy layer by layer), plus a Deferred task verbs block routing out-of-scope questions and a Command appendix of doca_bench-specific invocation classes.
The skill assumes a host where DOCA ≥ 2.7.0 is already installed (or the public NGC DOCA container is running at an equivalent version) and the operator has whatever permissions the public guide requires for doca_bench to bind devices and allocate resources on their platform.
What this skill deliberately does not ship
This skill is agent guidance, not a samples or scripts bundle. To keep the boundary clean, it deliberately does not contain — and pull requests should not add:
- **Specific flag strings or scenario / metric / attribute names
beyond what the public DOCA Bench guide documents.** The flag surface evolves and is install-specific; the documented invocations + --help on the installed version are the authoritative answer. Inventing a flag is the most common hallucination failure for this skill.
- Pre-baked example output or expected throughput numbers.
Bench output is device-, version-, firmware-, NUMA-, and tuning-specific. A captured number pinned to one platform and one DOCA version misleads operators on a different platform / version.
- Wrappers, parsers, or scripts in any language that consume
doca_bench CSV or stdout. The output formats are documented; if a user wants to script against them, the right answer is "read the live guide, write the parser against your installed version".
- A
samples/orreference/subtree. This is a thin
loader for a documented CLI; substantive material lives on the public page and in --help.
Loading order
- Read this
SKILL.mdfirst to confirm the user's question is
in scope (the user actually wants to invoke doca_bench for measurement, not learn about a DOCA library in general).
- **For what
doca_benchmeasures, the three-axis model, the
version overlay, the error taxonomy, observability surface, and safety posture, see [CAPABILITIES.md](CAPABILITIES.md).**
- **For the documented invocations and the smoke-before-bulk
workflow — configure, build, modify, run, test, debug — see [TASKS.md](TASKS.md).**
Related skills
- [
doca-public-knowledge-map](../../doca-public-knowledge-map/SKILL.md)
— routing to the public DOCA Bench page on docs.nvidia.com and the rest of the public DOCA documentation set.
- [
doca-version](../../doca-version/SKILL.md) — the canonical
version-detection chain, four-way match rule, NGC container semantics, and headers-win-over-docs rule. The ## Version compatibility section in this skill is a thin overlay on top of doca-version; the body lives there.
- [
doca-structured-tools-contract](../../doca-structured-tools-contract/SKILL.md)
— the bundle-wide contract for structured-output helper tools. Bench-runner / bench-snapshot executables that satisfy the detect-prefer-fallback-report loop are deferred to PR2; the contract is consumed here in advance so the ## Command appendix in [TASKS.md](TASKS.md) is infra-aware from PR1.
- [
doca-setup](../../doca-setup/SKILL.md) — env preparation,
install verification, hugepages, NUMA awareness, and the I have no install yet path with the public NGC DOCA container.
- [
doca-debug](../../doca-debug/SKILL.md) — the cross-cutting
debug ladder. Bench surfaces its own error taxonomy in [CAPABILITIES.md ## Error taxonomy](CAPABILITIES.md#error-taxonomy); when the cause turns out to be below DOCA (driver, firmware, NUMA), the bench taxonomy hands off to doca-debug.
- [
doca-caps](../doca-caps/SKILL.md) — the sibling DOCA tool
for the coarse per-device per-library capability snapshot. Bench probes capability at finer grain via its own query system; doca_caps is the cheaper first step to confirm the device is even visible to DOCA.
- The matching
libs/<library>skill — e.g.
[doca-comch](../../libs/doca-comch/SKILL.md), [doca-compress](../../libs/doca-compress/SKILL.md) — for the workload-side preconditions, capability-query rules, and error-taxonomy overlays of the library under test. Bench drives the library; the library skill explains what "healthy" means for it.