Array index chaining for tree structure save and restore in a process swapping system

摘要

A new system and method for outswapping a process is disclosed. The new system forms one or more working set list chains (also referred to as "page table chains") during the outswap process. The new system then conveniently locates and outswaps a number of page table pages of the process to be outswapped by traversing the working set list chains. In a preferred embodiment, the forming of each working set list chain is performed while traversing a working set list during outswapping of a number of body pages of a process. Each working set list entry potentially describes a page of virtual memory in use by the process to be outswapped. In a further aspect of the disclosed system, traversing the working set list of the process to be outswapped includes determining whether each one of the working set list entries indicates a private page table page. If an entry in the working set list indicates a private page table page, the present system adds a link to a working set list chain. In the disclosed system, a working set list entry is determined to indicate a private page table page if the page of virtual memory described by the working set list entry is within a page table structure associated with said process. The page table structure is hierarchical, and a separate working set chain is formed for one or more individual levels of the page table hierarchy.