Overview

Joule Profiler is designed to minimize measurement overhead while maintaining high performance, modularity, extensibility, and a strong separation of concerns.

This architecture enables an efficient asynchronous scheduling and minimizes the overhead introduced into the results. It makes easy the integration of new metric sources and allows user to define their own metric sources extensions without modifying the core.

flowchart LR
%%{init: {'flowchart': {'nodeSpacing': 20, 'rankSpacing': 30}}}%%

subgraph Sources
    RAPL
    NVML(Nvidia-Nvml)
    PERF(Perf events)
end

JouleProfiler((JouleProfiler))
Orchestrator

subgraph OUTPUTS[Output formats]
    Terminal
    JSON
    CSV
end

JouleProfiler e1@-->|Measure phases| Orchestrator
e1@{ animate: true }

JouleProfiler -->|Retrieve event| Orchestrator
Orchestrator -->|Join + retrieve results| JouleProfiler

Orchestrator e2@-->|Schedule| Sources
e2@{ animate: fast }

Orchestrator -->|Join tasks| Sources
Orchestrator e3@-->|Measure events| Sources
e3@{ animate: true }

JouleProfiler --> Terminal
JouleProfiler --> JSON
JouleProfiler --> CSV

linkStyle 0 stroke:#e67e22, stroke-width:2px
linkStyle 1 stroke:#e74c3c, stroke-width:2px
linkStyle 2 stroke:#e74c3c, stroke-width:2px
linkStyle 3 stroke:#9b59b6, stroke-width:2px
linkStyle 4 stroke:#e74c3c, stroke-width:2px
linkStyle 5 stroke:#e67e22, stroke-width:2px
linkStyle 6 stroke:#27ae60, stroke-width:2px
linkStyle 7 stroke:#27ae60, stroke-width:2px
linkStyle 8 stroke:#27ae60, stroke-width:2px

At a high level, Joule Profiler is composed of three main layers:

• Core Module - Contains all domain logic: orchestration, aggregation, and result modeling.
• CLI Module - Responsible for user input, command line arguments parsing, and startup wiring.
• Sources Workspace - Implementations of the different metric sources using the API traits.