On Mon, Mar 23, 2020 at 02:52:09PM +0900, js1304@xxxxxxxxx wrote: > From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> > > When implementing workingset detection for anonymous page, I found > some swapcache pages with NULL memcg. They are brought in by swap > readahead and nobody has touched it. > > The idea behind the workingset code is to tell on page fault time > whether pages have been previously used or not. Since this page > hasn't been used, don't store a shadow entry for it; when it later > faults back in, we treat it as the new page that it is. > > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
