Search icon
Arrow left icon
All Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Newsletters
Free Learning
Arrow right icon
Linux Kernel Programming - Second Edition

You're reading from  Linux Kernel Programming - Second Edition

Product type Book
Published in Feb 2024
Publisher Packt
ISBN-13 9781803232225
Pages 826 pages
Edition 2nd Edition
Languages
Author (1):
Kaiwan N. Billimoria Kaiwan N. Billimoria
Profile icon Kaiwan N. Billimoria

Table of Contents (16) Chapters

Preface 1. Linux Kernel Programming – A Quick Introduction 2. Building the 6.x Linux Kernel from Source – Part 1 3. Building the 6.x Linux Kernel from Source – Part 2 4. Writing Your First Kernel Module – Part 1 5. Writing Your First Kernel Module – Part 2 6. Kernel Internals Essentials – Processes and Threads 7. Memory Management Internals – Essentials 8. Kernel Memory Allocation for Module Authors – Part 1 9. Kernel Memory Allocation for Module Authors – Part 2 10. The CPU Scheduler – Part 1 11. The CPU Scheduler – Part 2 12. Kernel Synchronization – Part 1 13. Kernel Synchronization – Part 2 14. Other Books You May Enjoy
15. Index

Understanding, querying, and setting the CPU affinity mask

The task structure – the root data structure for the thread (or task), containing several dozen thread attributes – has a few attributes directly pertaining to scheduling: the priority (the nice as well as the Real-Time (RT) priority values), the scheduling class structure pointer, the runqueue the thread is on (if any), and so on. (FYI, we covered generic details on the task structure back in Chapter 6, Kernel Internals Essentials – Processes and Threads).

Among these is an important member, the CPU affinity bitmask (the actual structure member is cpumask_t *cpus_ptr. FYI, until the 5.3 kernel, it was a member named cpus_allowed; this was changed in this commit: https://github.com/torvalds/linux/commit/3bd3706251ee8ab67e69d9340ac2abdca217e733). This bit mask is just that: a bit mask of the CPU cores that the thread (represented by that task structure) is allowed to run on. A simple visualization helps...

lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at $15.99/month. Cancel anytime}