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license: Apache-2.0 name: doca-perftest description: > Use this skill when the user is running DOCA Perftest (doca_perftest), the RDMA benchmark that measures bandwidth, message rate and latency for RDMA verbs, point-to-point or across a cluster, with an optional DOCA Verbs backend (-r dv) or GPUNetIO engine (--engine gpunetio). Trigger even when the user does not say "DOCA Perftest" — implicit phrasings include "how do I benchmark RDMA write bandwidth with DOCA", "run ib_write_bw but across 8 nodes", "perftest says the device is busy", "my latency numbers differ between client and server", "launch the server over SSH", or "run an all-to-all RDMA test from a JSON scenario". Refuse and route elsewhere for DOCA install (doca-setup), DOCA Bench (doca-bench), and application-level throughput. metadata: author: NVIDIA doca-feedback@nvidia.com kind: tool doca_version: "3.5" tags: - doca - rdma - benchmark - perftest compatibility: > Requires DOCA 3.5 or later on Linux with a ConnectX or BlueField RDMA device, libibverbs (DOCA-OFED or upstream rdma-core), and OpenMPI for multi-node modes. The DOCA Verbs backend needs the doca-verbs package; the GPUNetIO engine needs doca-gpunetio, CUDA and a Volta+ GPU. Run benchmarks only on a trusted, non-shared fabric.

DOCA Perftest

When to load this skill

Load this skill when the user wants to — or the agent needs to — run doca_perftest on a host with DOCA installed. Concretely:

• Measuring RDMA bandwidth, message rate, or latency between two hosts (point-to-point) with a verb such as write / read / send.
• Running the same benchmark across many nodes — JSON scenario or --traffic_pattern (pair-wise, all-to-all), orchestrated over OpenMPI / passwordless SSH.
• Comparing the IBV and DOCA Verbs backends (-r ibv vs -r dv) or driving the GPUNetIO engine (--engine gpunetio).
• Interpreting a run: client-vs-server number drift, "device busy", inconsistent latency across runs.

Do not load this skill for DOCA install (doca-setup), the doca-bench harness, Flow pipeline tuning (doca-flow-tune), or application-level throughput.

Examples

• "Measure RDMA write bandwidth between two ConnectX-7 hosts with 64 KB messages." Point-to-point: run the server, then the client with -n.
• "I need latency across 16 nodes, all-to-all." Multi-node: JSON scenario or --traffic_pattern, with OpenMPI.
• "Compare the IBV and DOCA Verbs drivers on the same device." Same command, -r ibv vs -r dv.

Instructions

Follow the loading order below. Open TASKS.md for the commands and CAPABILITIES.md for what the tool can measure and what it does not.

Where to start: DOCA Perftest is the DOCA 3.5 replacement for legacy ib_write_bw / ib_send_lat plus the orchestration scripts used to run them on many nodes. Start at TASKS.md ## point-to-point for a first run. Use ## multi-node for scenarios and ## debug when a run fails or the numbers look wrong.

If DOCA is not installed, route to doca-setup/SKILL.md. Client and server must run the same DOCA Perftest version; check with doca-version/SKILL.md before comparing numbers across hosts. If the question is about GPU-initiated RDMA in the user's own code, route to doca-gpunetio/SKILL.md.

Example questions this skill answers well

• "Run a point-to-point RDMA write bandwidth test." Use -d <dev> -n <server> -v write -m bw -s <size> -D <sec>; the client coordinates the server side over SSH (requires SSH key exchange set up beforehand).
• "Benchmark 16 nodes at once and get one report." Use a JSON scenario or --traffic_pattern; the report aggregates per device, node and test.
• "Latency differs between runs." Check the latency mode, the core and NUMA placement, and whether both sides use the same message size and verb.

Loading order

1. This file for scope and routing.
2. TASKS.md for the exact command for the job you are doing.
3. CAPABILITIES.md when you need to know whether a verb, driver, memory type or traffic pattern is supported.

Do not open every companion file.

Scope boundaries

• Installs and driver packages: doca-setup/SKILL.md.
• Version matching across client, server and DOCA release: doca-version/SKILL.md.
• Any change to NIC or eswitch state, firmware, or host kernel settings (hugepages, IOMMU, PCIe rebind): follow doca-hardware-safety/SKILL.md first.
• Failure diagnosis: doca-debug/SKILL.md for the layer ladder, then the TASKS.md ## debug anchor here.
• Upstream CPU-initiated ib_write_bw: this tool replaces it on DOCA 3.5; do not mix the two in one comparison without saying so.