On Tue, May 24, 2022 at 07:40:05PM -0700, Roman Gushchin wrote:
> On Tue, May 24, 2022 at 02:05:50PM +0800, Muchun Song wrote:
> > We need to make sure that the page is deleted from or added to the
> > correct lruvec list. So add a VM_BUG_ON_FOLIO() to catch invalid
> > users.
> >
> > Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
> > ---
> > include/linux/mm_inline.h | 6 ++++++
> > mm/vmscan.c | 1 -
> > 2 files changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
> > index ac32125745ab..30d2393da613 100644
> > --- a/include/linux/mm_inline.h
> > +++ b/include/linux/mm_inline.h
> > @@ -97,6 +97,8 @@ void lruvec_add_folio(struct lruvec *lruvec, struct folio *folio)
> > {
> > enum lru_list lru = folio_lru_list(folio);
> >
> > + VM_BUG_ON_FOLIO(!folio_matches_lruvec(folio, lruvec), folio);
> > +
> > update_lru_size(lruvec, lru, folio_zonenum(folio),
> > folio_nr_pages(folio));
> > if (lru != LRU_UNEVICTABLE)
> > @@ -114,6 +116,8 @@ void lruvec_add_folio_tail(struct lruvec *lruvec, struct folio *folio)
> > {
> > enum lru_list lru = folio_lru_list(folio);
> >
> > + VM_BUG_ON_FOLIO(!folio_matches_lruvec(folio, lruvec), folio);
> > +
> > update_lru_size(lruvec, lru, folio_zonenum(folio),
> > folio_nr_pages(folio));
> > /* This is not expected to be used on LRU_UNEVICTABLE */
> > @@ -131,6 +135,8 @@ void lruvec_del_folio(struct lruvec *lruvec, struct folio *folio)
> > {
> > enum lru_list lru = folio_lru_list(folio);
> >
> > + VM_BUG_ON_FOLIO(!folio_matches_lruvec(folio, lruvec), folio);
> > +
> > if (lru != LRU_UNEVICTABLE)
> > list_del(&folio->lru);
> > update_lru_size(lruvec, lru, folio_zonenum(folio),
> > diff --git a/mm/vmscan.c b/mm/vmscan.c
> > index 761d5e0dd78d..6c9e2eafc8f9 100644
> > --- a/mm/vmscan.c
> > +++ b/mm/vmscan.c
> > @@ -2281,7 +2281,6 @@ static unsigned int move_pages_to_lru(struct list_head *list)
> > continue;
> > }
> >
> > - VM_BUG_ON_PAGE(!folio_matches_lruvec(folio, lruvec), page);
>
> The commit log describes well why we need to add new BUG_ON's. Please, add
> something on why this is removed.
>
OK. Will do in v5.
Thanks.
