Power and Performance

Chapter 6

Introduction to Profiling

Abstract

This chapter provides an introduction to the process of performance profiling. The first section covers the fundamentals of the core and uncore PMU available on Intel(R) processors. The Section 6.2 explores the Top-Down Hierarchical technique for using PMU events to identify issues affecting pipeline efficiency.

Keywords

PMU

Top-down

Event counters

Homines quod volunt credunt (Men believe what they want)

Julius Caesar

Chapter Contents

6.1 PMU   106

6.1.1 Event Counters   107

6.1.2 Using Event Counters   109

6.2 Top-Down Hierarchical Analysis   110

6.2.1 Front End Bound   112

6.2.2 Back End Bound   114

Memory Bound   114

Core Bound   116

6.2.3 Bad Speculation   117

6.2.4 Retire   117

References ...