On Mon, 9 Mar 2020, David Hildenbrand wrote: > >> I still prefer something like > >> > >> diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h > >> index fd6d4670ccc3..7538501230bd 100644 > >> --- a/include/linux/page-flags.h > >> +++ b/include/linux/page-flags.h > >> @@ -63,6 +63,10 @@ > >> * page_waitqueue(page) is a wait queue of all tasks waiting for the page > >> * to become unlocked. > >> * > >> + * PG_swapbacked used with anonymous pages (PageAnon()) indicates that a > >> + * page is backed by swap. Anonymous pages without PG_swapbacked are > >> + * pages that can be lazily freed (e.g., MADV_FREE) on demand. > >> + * > >> * PG_uptodate tells whether the page's contents is valid. When a read > >> * completes, the page becomes uptodate, unless a disk I/O error happened. > >> * > > > > Why not just send a formal patch? So Andrew can just pick anything he > > likes. I am totally OK with that. > > Because you're working on cleaning this up. > > > > >> and really don't like the use of !__PageLazyFree() instead of PageSwapBacked(). > > > > If adopted, !__PageLazyFree() should only be used in the context where > > we really want to check whether pages are freed lazily. Otherwise, > > PageSwapBacked() should be used. > > > > Yeah, and once again, personally, I don't like this approach. E.g., > ClearPageLazyFree() sets PG_swapbacked. You already have to be aware > that this is a single flag being used in the background and what the > implications are. IMHO, in no way better than the current approach. I > prefer better documentation instead. > Fully agreed.
