On Mon, Mar 01, 2021 at 02:50:07PM +0300, Kirill A. Shutemov wrote: > On Fri, Feb 26, 2021 at 12:13:14PM +0000, Matthew Wilcox wrote: > > On Fri, Feb 26, 2021 at 02:17:18AM -0700, Yu Zhao wrote: > > > All places but one test, set or clear PG_active and PG_unevictable on > > > small or head pages. Use compound_head() explicitly for that singleton > > > so the rest can rid of redundant compound_head(). > > > > How do you know it's only one place? I really wish you'd work with me > > on folios. They make the compiler prove that it's not a tail page. > > +1 to this. > > The problem with compound_head() is systemic and ad-hoc solution to few > page flags will only complicate the picture. Well, I call it an incremental improvement, and how exactly does it complicate the picture? I see your point: you prefer a complete replacement. But my point is not about the preference; it's about presenting an option: I'm not saying we have to go with this series; I'm saying if you don't want to wait, here is something quick but not perfect.