Home > Store

Understanding the Linux Virtual Memory Manager

Register your product to gain access to bonus material or receive a coupon.

Understanding the Linux Virtual Memory Manager

  • By
  • Published Apr 29, 2004 by Pearson.


  • Sorry, this book is no longer in print.
Not for Sale


  • Copyright 2004
  • Dimensions: 7" x 9-1/4"
  • Pages: 752
  • Edition: 1st
  • Book
  • ISBN-10: 0-13-145348-3
  • ISBN-13: 978-0-13-145348-7

A programmer wanting to understand the workings of the Linux VM today literally has no choice but to study the kernel source code, line-by-line - an excruciatingly difficult and time-consuming task. This book dedicates itself to explaining, in detail, how the memory manager is implemented in Linux, thereby cutting down the time needed to understand it from many months to mere weeks. The Linux VM is the single most important component of the Linux kernel. The behavior of the VM affects all other kernel subsystems, and has a dramatic impact on overall system performance. This book is unique in that not only does it describe the Linux VM itself in unprecedented detail, it also includes the theoretical foundations for it which is of interest to both developers and students but has been omitted from recent Linux kernel related material. It is split into three parts. The first part begins with an introduction on how to approach reading the code of an open source project. It then provides a detailed description of the VM architecture with the aid of numerous diagrams and call graphs, which is suitable for people who need a clear understanding of how the VM functions. The second part is a detailed line-by-line description of the C source modules (source code commentary) that implement the VM in the Linux 2.4 kernel. The third part describes new features in the upcoming 2.6 kernel.

Sample Content

Online Sample Chapter

Page Table Management

Table of Contents



Getting Started. Managing the Source. Browsing the Code. Reading the Code. Submitting Patches.

2. Describing Physical Memory.

Nodes. Zones. Zone Initialization. Initializing mem map. Pages. Mapping Pages to Zones. High Memory. Whats New in 2.6.

3. Page Table Management.

Describing the Page Directory. Describing a Page Table Entry. Using Page Table Entries. Translating and Setting Page Table Entries. Allocating and Freeing Page Tables. Kernel Page Tables. Mapping Addresses to a struct page. Translation Lookaside Bu.er (TLB). Level 1 CPU Cache Management. Whats New in 2.6.

4. Process Address Space.

Linear Address Space. Managing the Address Space. Process Address Space Descriptor. Memory Regions. Exception Handling. Page Faulting. Copying to/from Userspace. Whats New in 2.6.

5. Boot Memory Allocator.

Representing the Boot Map. Initializing the Boot Memory Allocator. Initializing bootmem data. Allocating Memory. Freeing Memory. Retiring the Boot Memory Allocator. Whats New in 2.6.

6. Physical Page Allocation.

Managing Free Blocks. Allocating Pages. Free Pages. Get Free Page (GFP) Flags. Process Flags. Avoiding Fragmentation. Whats New in 2.6.

7. Noncontiguous Memory Allocation.

Describing Virtual Memory Areas. Allocating a Noncontiguous Area. Freeing a Noncontiguous Area. Whats New in 2.6.

8. Slab Allocator.

Caches. Slabs. Objects. Sizes Cache. Per-CPU Object Cache. Slab Allocator Initialization. Interfacing With the Buddy Allocator. Whats New in 2.6.

9. High Memory Management.

Managing the PKMap Address Space. Mapping High Memory Pages. Unmapping Pages. Mapping High Memory Pages Atomically. Bounce Bu.ers. Emergency Pools. Whats New in 2.6.

10. Page Frame Reclamation.

Page Replacement Policy. Page Cache. LRU Lists. Shrinking All Caches. Swapping Out Process Pages. Pageout Daemon (kswapd). Whats New in 2.6.

11. Swap Management.

Describing the Swap Area. Mapping Page Table Entries to Swap Entries. Allocating a Swap Slot. Swap Cache. Reading Pages From Backing Storage. Writing Pages to Backing Storage. Reading/Writing Swap Area Blocks. Activating a Swap Area. Deactivating a Swap Area. Whats New in 2.6.

12. Shared Memory Virtual Filesystem.

Initializing the Virtual Filesystem. Using shmem Functions. Creating Files in tmpfs. Page Faulting Within a Virtual File. File Operations in tmpfs. Inode Operations in tmpfs. Setting Up Shared Regions. System V IPC. Whats New in 2.6.

13. Out Of Memory Management.

Checking Available Memory. Determining OOM Status. Selecting a Process. Killing the Selected Process. Is That It? Whats New in 2.6.

14. The Final Word.

A. Introduction.

B. Describing Physical Memory.

Initializing Zones. Page Operations.

C. Page Table Management.

Page Table Initialization. Page Table Walking.

D. Process Address Space.

Process Memory Descriptors. Creating Memory Regions. Searching Memory Regions. Locking and Unlocking Memory Regions. Page Faulting. Page-Related Disk I/O.

E. Boot Memory Allocator.

Initializing the Boot Memory Allocator. Allocating Memory. Freeing Memory. Retiring the Boot Memory Allocator.

F. Physical Page Allocation.

Allocating Pages. Allocation Helper Functions. Free Pages. Free Helper Functions.

G. Noncontiguous Memory Allocation.

Allocating a Noncontiguous Area. Freeing a Noncontiguous Area.

H. Slab Allocator.

Cache Manipulation. Slabs. Objects. Sizes Cache. Per-CPU Object Cache. Slab Allocator Initialization. Interfacing with the Buddy Allocator.

I. High Memory Mangement.

Mapping High Memory Pages. Mapping High Memory Pages Atomically. Unmapping Pages. Unmapping High Memory Pages Atomically. Bounce Bu.ers. Emergency Pools.

J. Page Frame Reclamation.

Page Cache Operations. LRU List Operations. Re.lling inactive list. Reclaiming Pages From the LRU Lists. Shrinking All Caches. Swapping Out Process Pages. Page Swap Daemon.

K. Swap Management.

Scanning for Free Entries. Swap Cache. Swap Area I/O. Activating a Swap Area. Deactivating a Swap Area.

L. Shared Memory Virtual Filesystem.

Initializing shmfs. Creating Files in tmpfs. File Operations in tmpfs. Inode Operations in tmpfs. Page Faulting Within a Virtual File. Swap Space Interaction. Setting Up Shared Regions. System V IPC.

M. Out of Memory Management.

Determining Available Memory. Detecting and Recovering From OOM.


Code Commentary Index.


About the Author.


Submit Errata

More Information

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020