rocprofv3-profiler

Profile AMD GPU applications and identify performance bottlenecks using rocprofv3.

Quick Start

1. Run Profiler

python3 scripts/rocprof_wrapper.py --mode counters -- ./your_app [args]

Modes:

• counters (default): Collect key performance counters for bottleneck analysis
• trace: Collect kernel execution traces (timing only)
• full: Collect both counters and traces

Options:

• --output-dir <dir>: Output directory (default: ./rocprof_output)
• --counters <file>: Custom counter input file (optional)
• --kernel <name>: Target specific kernel by name

2. Parse Results

python3 scripts/parse_profile.py <output_dir>

Returns structured JSON with:

• Per-kernel metrics summary
• Bottleneck classification (compute/memory/lds/latency bound)
• Optimization hints
• Path to raw data

Example Workflow

# Profile application
python3 scripts/rocprof_wrapper.py --mode counters -- ./matrix_multiply 1024

# Parse and analyze
python3 scripts/parse_profile.py ./rocprof_output

Sample output:

{
  "kernels": [{
    "name": "matmul_kernel",
    "metrics": {
      "duration_ns": 145230,
      "occupancy_pct": 45.2,
      "valu_busy_pct": 78.5,
      "lds_bank_conflict_rate": 0.12,
      "l2_hit_rate": 0.65
    },
    "bottleneck": {
      "type": "memory_bound",
      "confidence": "high",
      "detail": "Low L2 hit rate (65%) with high memory stall cycles"
    }
  }],
  "raw_data_path": "./rocprof_output/pmc_1/counter_collection.csv"
}

Bottleneck Classification

The parser classifies kernels into these categories:

Bottleneck	Indicators
compute_bound	High VALU/MFMA busy, low memory stalls
memory_bound	High memory latency, low cache hit rates
lds_bound	High LDS bank conflicts or LDS instruction stalls
latency_bound	Low occupancy with high instruction latency
balanced	No single dominant bottleneck

Reference Documentation

• hardware_counters.md: Key AMD GPU counters and their meaning
• bottleneck_heuristics.md: Detailed bottleneck classification rules

Direct rocprofv3 Usage

For advanced use cases, invoke rocprofv3 directly:

# List available counters
rocprofv3 -L

# Trace kernel execution
rocprofv3 --kernel-trace --stats -- ./app

# Collect specific counters
rocprofv3 -i counters.txt -- ./app

Counter input file format (counters.txt):

pmc: SQ_WAVES SQ_INSTS_VALU SQ_INSTS_VMEM
pmc: TCC_HIT TCC_MISS

Troubleshooting

"rocprofv3 not found": Ensure ROCm is installed and /opt/rocm/bin is in PATH.

"No GPU detected": Check rocm-smi output and HSA_VISIBLE_DEVICES environment variable.

Multi-pass collection: If too many counters requested, rocprofv3 replays the kernel. Use fewer counters per pmc line.