On Fri, Aug 26, 2022 at 11:15 AM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > On Fri, Aug 26, 2022 at 11:20:58AM +0800, Yin, Fengwei wrote: > > On 8/26/2022 2:46 AM, Matthew Wilcox wrote: > > > There's a number of ways of solving this. I'm interested in seeing > > > which one Minchan thinks is best. > > > > My understanding is: > > PageTransCompound() return false for compound page if THP is disabled > > in kernel config. Replacing PageTransCompound() with PageCompound() > > could work here. But for the long term, folio should be the answer. :). > > Yes, ultimately, isolate_lru_page() is going away as an interface > and one will have to call folio_isolate_lru(). But should > madvise_cold_or_pageout_pte_range() even be getting called for VMAs > which are mmaps of af_packet? can_madv_lru_vma() rules out a number > of different types of VMA; should it also be ruling out af_packet VMAs? Agreed. > If so, how? We should add a reliable helper to tell whether a file VMA is reclaimable or not. I don't think we have one. Currently MGLRU checks mapping->a_ops->read_folio for file VMAs to determine whether they are reclaimable.
