Checkpoint/restore is a feature that allows to freeze a set of running processes and save their complete state. This state can later be restored, so the processes resume exactly the way they were running before. This feature opens a set of possibilities, such as live migration, fast start of a huge process, or kernel upgrade without service interruption.
While such functionality exists as out-of-tree projects, many attempts to merge it upstream had failed, mostly for the code complexity reasons. We found a way to overcome this by implementing most of the required pieces in userspace, using the existing kernel APIs and extending those if necessary. This is what Checkpoint and Restore in Userspace (aka CRIU) project is about.
The talk is about the current state of the project, and is mostly focused on the recent upstream kernel changes and the abilities of the CRIU userspace tool.