Migration optimization idea #198
Description
There are many miner actors with no live or dead sectors at all
If we can skip as much processing for them as possible we might be able to save some constant work per actor. Assuming there are many such actors we might be able to halve or third etc total work.
TODO
- count how many totally inactive miner actors
- figure out if there is a way to cheaply as possible determine if there are no sectors (this might be as expensive as the noop migration)