Johannes Weiner <hannes@xxxxxxxxxxx> wrote: > So I fully agree with the motivation behind this patch. But I do > wonder why it's special-casing the commmon case instead of the rare > case. It comes at a huge cost. Short term, the churn of replacing > 'page' with 'folio' in pretty much all instances is enormous. > > And longer term, I'm not convinced folio is the abstraction we want > throughout the kernel. If nobody should be dealing with tail pages in > the first place, why are we making everybody think in 'folios'? Why > does a filesystem care that huge pages are composed of multiple base > pages internally? This feels like an implementation detail leaking out > of the MM code. The vast majority of places should be thinking 'page' > with a size of 'page_size()'. Including most parts of the MM itself. I like the idea of logically separating individual hardware pages from abstract bundles of pages by using a separate type for them - at least in filesystem code. I'm trying to abstract some of the handling out of the network filesystems and into a common library plus ITER_XARRAY to insulate those filesystems from the VM. David
