实时交互进程的并发检查点技术

Concurrent Checkpoint/Restart Mechanism for Real-Time Interactive Processes

提出了一种并发检查点技术,允许进程在设置检查点的同时尽可能保持继续执行。在拷贝进程地址空间(设置检查点的步骤之一)的同时,阻塞页面写操作并拷贝该原始页面到指定缓冲区,达到不需要在拷贝进程空间的同时停止该被设置检查点进程,最后结合缓冲区中拷贝页面,得到具有一致性的进程状态的映像文件。实验结果表明,可以减少20%～70%被检查进程的停止时间,使得检查点的设置与进程的执行具有一定的并发性。减少被检查进程在设置检查点时的停止时间,适合实时性和交互性要求较高的进程设置检查点。

This paper presents a new concurrent checkpoint/restart mechanism,it allows the checkpointed process（checkpointee） without stopping while doing checkpointing to some extent.The checkpointee can continue to run until a write request is captured by tracing TLB during dumping memory pages（which is a critical step of doing checkpoint）.At that time,the checkpoint module will copy the requested page to the designated memory buffer,then enable the write operation.Then,it can form an image file with consistent process state by using original pages which copied in the designate memory buffer.The experimental results show that this mechanism can reduce 20% ~70% stopping time of checkpointee to ensure the concurrency between doing checkpoint and execution of checkpointee.This mechanism is a quite good choice for hign real-time and interactive priority applications.