On Tue, Jul 20, 2021 at 06:35:50PM +0300, Mike Rapoport wrote: > On Tue, Jul 20, 2021 at 04:23:29PM +0100, Matthew Wilcox wrote: > > Which patch did you go up to for that? If you're going past patch 50 or > > so, then you're starting to add functionality (ie support for arbitrary > > order pages), so a certain amount of extra code size might be expected. > > I measured 6KB at patch 32 or so, then between patch 32 & 50 was pretty > > much a wash. > > I've used folio_14 tag: > > commit 480552d0322d855d146c0fa6fdf1e89ca8569037 (HEAD, tag: folio_14) > Author: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> > Date: Wed Feb 5 11:27:01 2020 -0500 > > mm/readahead: Add multi-page folio readahead Probably worth trying the for-next tag instead to get a meaningful comparison of how much using folios saves over pages. I don't want to give the impression that this is all that can be saved by switching to folios. There are still hundreds of places that call PageFoo(), SetPageFoo(), ClearPageFoo(), put_page(), get_page(), lock_page() and so on. There's probably another 20KB of code that can be removed that way.
