Arm Barriers 101: What Are Barriers And Why Do We Need Them?

Arm Barriers 101: What Are Barriers And Why Do We Need Them?
Published 5/2025
MP4 | Video: h264, 1920×1080 | Audio: AAC, 44.1 KHz

What you’ll learn

Discover why Arm defines a weakly-ordered memory model

Explore the rules dictating whether two memory access may be reordered

Learn how to use barriers in software to manually enforce ordering

Learn how to descope barriers to mitigate any potential impacts on system performance

Requirements

Beginner friendly!

Assumes no prior Arm Architecture experience.

Some basic C/C++ programming experience is recommended, but not required.

Description

Overview

Section 1: What are barriers, and why do we need them?

Lecture 1 Why weakly-ordered?

Lecture 2 System-level reordering

Lecture 3 Dependencies and successors

Lecture 4 Idempotence and speculation

Lecture 5 Data Memory Barriers

Lecture 6 Shareability domains

Lecture 7 Conventions and expectations

Lecture 8 Atomics and synchronization

Lecture 9 Workshop

Lecture 10 Quiz

Engineers at all experience levels working on Arm-based platforms.,Firmware Engineers.,Kernel Engineers.,Hypervisor Engineers.,Device Driver Engineers.,Application Developers.