Research on status reconversion of VAD in the checkpoint of windows process

Checkpoint is very important to system fault tolerance; the user space memory of specified process is saved as completely as possible in both kernel-level and user-level check pointing. While user space memory on Windows platform is divided into several blocks, which are possible in different states, but access state (i.e. committed state) is only one of them. This paper discusses the principle of user space memory management on Windows platform, and especially reveals the mechanism of region which includes virtual address continuous pages with same attributes. This paper presents the structure of user space virtual memory and the approaches to saving and recovery of user space virtual memory. The result is the same as expected.