This is very helpful (for someone who has never worked on Darwin)! The algorithm uses two FIFO lists with a "visited" bit (lazy promotion), and is a great idea!

This is very helpful (for someone who has never worked on Darwin)! The algorithm uses two FIFO lists with a "visited" bit (lazy promotion), and is a great idea! There are two differences between what is described and our algorithm, 1. the two FIFO lists are not fix-sized, which cannot guarantee quick demotion; 2. new data (hard fault) are inserted into the active list (I assume it is large than the inactive list), which is different from the quick demotion.