Performance Tuning for Linux® Servers

Chapter Nine. The Linux Virtual Memory—Performance Implications

By Dominique Heger

Introduction

The virtual memory subsystem can be considered the core of any UNIX system. This chapter discusses the implementation of the virtual memory system and the effects and impacts on almost every other subsystem in the operating system. The chapter first elaborates on some of the basic memory management issues; secondly, it outlines a more detailed analysis of how the Linux operating system incorporates virtual memory management tasks. The virtual memory subsystem enables a process (also labeled a task or default thread) to view linear ranges of bytes in the address space. This is allowed regardless of the physical layout or the fragmentation encountered in ...