Sun Performance and Tuning: Java™ and the Internet, Second Edition

The Life Cycle of a Typical Physical Memory Page

This section provides additional insight into the way memory is used and makes the following sections easier to understand. The sequence described is an example of some common uses of pages; there are many other possibilities.

1. Initialization — A Page Is Born

   When the system boots, all free memory is formed into pages, and a kernel data structure is allocated to hold the state of every page in the system.

2. Free — An Untouched Virgin Page

   All the memory is put onto the free list to start with. At this stage, the content of the page is undefined.

3. ZFOD — Joining a BSS Segment

   When a program accesses a BSS segment for the very first time, a minor page fault occurs and a Zero Fill On Demand (ZFOD) operation ...