On Tue, Dec 08, 2020 at 06:24:00PM -0700, Yu Zhao wrote:
> We are capable of SetPageWorkingset based on refault distances after
> commit aae466b0052e ("mm/swap: implement workingset detection for anonymous LRU")
> This is done by workingset_refault(), which is right above the
> unconditional SetPageWorkingset deleted by this patch.
>
> The unconditional SetPageWorkingset miscategorizes pages that are
> read ahead or never belonged to the working set (e.g., tmpfs pages
> accessed by fd). When those pages are swapped in (after they were
> swapped out) for the first time, they skew PSI (when using
> async swap). When this happens again, depending on their refault
> distances, they might skew workingset_restore_anon counter in
> addition to PSI because their shadows say they were part of the
> working set.
>
> Signed-off-by: Yu Zhao <yuzhao@xxxxxxxxxx>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Thanks
