[CRIU] rewriting images via criu (or crit?)

[Pavel Emelyanov]

On 10/27/2014 08:32 PM, Tycho Andersen wrote:

>> I mean, yes, plugin isn't very flexible tool, but it should be faster than
>> calling
>> a separate tool to modify image. For flexibility one could use crit written
>> in python.
> 
> Isn't it mostly just saving you an extra fork()? Assuming the
> performance critical bits of crit were written in C, shouldn't it be
> essentially equivalent to doing it in criu?

How about doing restore-time modification in streaming mode?
Like -- criu forks crit with 2 pipes (1 unix seq-packet socket),
then sends there images reading modified versions back. This
should save a lot of time for fork() (we do fork() a lot in criu
restore anyway, e.g. for netns setup), but will still make it
possible to use Python powers for images manipulations.

Thanks,
Pavel