On Mon, Jun 24, 2024 at 11:56 AM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > On Mon, Jun 24, 2024 at 11:53:30AM -0700, Yosry Ahmed wrote: > > After a page is swapped out during reclaim, __remove_mapping() will > > call __delete_from_swap_cache() to replace the swap cache entry with a > > shadow entry (which is an xa_value). > > Special entries are disjoint from shadow entries. Shadow entries have > the last two bits as 01 or 11 (are congruent to 1 or 3 modulo 4). > Special entries have values below 4096 which end in 10 (are congruent > to 2 modulo 4). You are implying that we would no longer have a shadow entry for such zero folios, because we will be storing a special entry instead. Right? This is the "fundamental" change I am talking about.
