On Sun, Jun 04, 2023 at 11:09:25AM -0700, Darrick J. Wong wrote: > On Fri, Jun 02, 2023 at 11:24:42PM +0100, Matthew Wilcox (Oracle) wrote: > > + do { > > + err = -ENOMEM; > > + if (order == 1) > > + order = 0; > > Doesn't this interrupt the scale-down progression 2M -> 1M -> 512K -> > 256K -> 128K -> 64K -> 32K -> 16K -> 4k? What if I want 8k folios? You can't have order-1 file/anon folios. We have deferred_list in the third page, so we have to have at least three pages in every large folio. I forget exactly what it's used for; maybe there's a way to do without it, but for now that's the rule.