I feel like there’s this misconception that mapping data from disk is free (this is also mentioned in the README you linked). It’s not. If the pages are clean t

I feel like there’s this misconception that mapping data from disk is free (this is also mentioned in the README you linked). It’s not. If the pages are clean then you do get the benefit of being able to discard them when pressure is high, but if you need them again they have to be paged in. And for most apps there is no sharing of this data, so loading it will be accounted for against your process rather than being amortized across several like system libraries might be. Sure, it’s definitely better than dirty anonymous pages, but it’s not free.