The page describes thoughts about how to take an existing process and apply images into it, instead of turn CRIU process into target one.
This feature is useful for
- Reverting to snapshot
- In case process keep running after a snapshot, reverting back might be faster if not restoring from images, but applying those directly on the running tasks
- FT case
- In fault tolerant systems master node would send updates to slave one(s) and the latter guys would benefit from ability to "add" the snapshot update onto existing tasks
There's a technical problem in it -- currently CRIU restores data from images into itself. Only a small portion of code is executed in a PIE mode (called "restorer context") and that is run in a target task environment. In apply-images mode we'd have to push parasite into target task and run all the restoration code in it. This is a lot of patching.