DragonFly kernel List (threaded) for 2003-09
Re: checkpoint/restart milestone 1
: Ah, sounds good! I looked into this idea some time ago, when
: you can suspend a process, store it's state in an image file
: and then you can use it whenever you want for reloading it
: The only issue I had with such kind of thing was to do with the
: state that the kernel keeps, like file descriptor tables, and
: vnode references, which are invalidated after a reboot, because
: a new table is created.
: One way to solve this problem was to index into the filedesc
: table and make out which files were open, save this information
: in some sort part of the process image, and then when the
: image is loaded, we recreate references to the files originally
: referenced; although, this is just an overall perspective on the
: topic. I am sure there were other roadblocks which I faced.
: Anyway, this sounds ilke a really good idea! :-)
Yah. Obviously the feature will start out being rather primitive, but
it should be possible to add functionality incrementally without having
to ripup the stuff already done. I can envision (in the future) a
program setting up a SIGCHKPT signal, for example, which would allow the
program to implement its own checkpoint restore function based on a
resource list given to it by the system.