lpsm!

[H. Peter Anvin]

Jacques Mony wrote:
> How do you deal with the filesystem commits? We would need a way to
> make sure the checkpoint is totally written to disk before we consider
> it is. Is there a user space solution to this?

The commits are handled by forking the process (thereby creating a 
snapshot), then writing the log, and using fsync and fdatasync() to 
enforce coherency.

Both blocking and nonblocking checkpointing is available; blocking 
checkpointing obviously stops everything until the checkpoint is 
complete; nonblocking checkpointing allows execution to continue, but 
you can *always* revert to a checkpoint; for nonblocking checkpoints 
this may be the one before the latest instead of the latest if the 
checkpoint wasn't complete by the time the process was terminated.

	-hpa