intel-vtune-amd-uprof

Intel VTune & AMD uProf

Purpose

Guide agents through CPU microarchitecture profiling with Intel VTune Profiler (free Community Edition) and AMD uProf: hotspot identification, microarchitecture analysis, memory access pattern optimization, pipeline stall diagnosis, and roofline model analysis.

Triggers

• "How do I use Intel VTune to profile my code?"
• "What are pipeline stalls and how do I reduce them?"
• "How do I analyze memory bandwidth with VTune?"
• "What is the roofline model and how do I use it?"
• "How do I use AMD uProf as a free alternative to VTune?"
• "My code has good cache hit rates but is still slow"

Workflow

1. VTune setup (free Community Edition)

# Download Intel VTune Profiler (Community Edition — free)
# https://www.intel.com/content/www/us/en/developer/tools/oneapi/vtune-profiler.html

# Install on Linux
source /opt/intel/oneapi/vtune/latest/env/vars.sh

# CLI usage
vtune -collect hotspots ./prog
vtune -collect microarchitecture-exploration ./prog
vtune -collect memory-access ./prog

# View results in GUI
vtune-gui &
# File → Open Result → select .vtune directory

# Or use amplxe-cl (legacy CLI)
amplxe-cl -collect hotspots ./prog
amplxe-cl -report hotspots -r result/

2. Analysis types

Analysis	What it finds	When to use
Hotspots	CPU-bound functions	First step — find where time is spent
Microarchitecture Exploration	IPC, pipeline stalls, retired instructions	After hotspot — why is the hotspot slow?
Memory Access	Cache misses, DRAM bandwidth, NUMA	Memory-bound code
Threading	Lock contention, parallel efficiency	Multithreaded code
HPC Performance	Vectorization, memory, roofline	HPC / scientific code
I/O	Disk and network bottlenecks	I/O-bound code

3. Hotspot analysis

# Collect and report hotspots
vtune -collect hotspots -result-dir hotspots_result ./prog

# Report top functions by CPU time
vtune -report hotspots -r hotspots_result -format csv | head -20

# CLI output example:
# Function       CPU Time  Module
# compute_fft    4.532s    libfft.so
# matrix_mult    2.108s    prog
# parse_input    0.234s    prog