Hardware Performance Counters

Purpose

Guide agents through hardware performance counter analysis: collecting PMU events with perf stat -e, using the PAPI library for portable counter access, interpreting cache miss rates and branch misprediction ratios, computing IPC, and correlating events to source lines with perf annotate.

Triggers

• "How do I measure cache miss rate with perf?"
• "How do I count branch mispredictions?"
• "How do I compute IPC (instructions per clock) with perf?"
• "How do I use the PAPI library for hardware counters?"
• "How do I see which source lines cause the most cache misses?"
• "How do I measure memory bandwidth with performance counters?"

Workflow

1. perf stat — basic counter collection