mm: mglru: fix add unevictable folio to lruvec->lists

Message ID 20230914140823.1732-1-justinjiang@vivo.com
State New
Headers
Series mm: mglru: fix add unevictable folio to lruvec->lists |

Commit Message

Zhiguo Jiang Sept. 14, 2023, 2:08 p.m. UTC
  The unevictable folio is not supported to add to lruvec->lists
in lruvec_add_folio().

So use lruvec_add_folio_tail() instead of lruvec_add_folio()
to add unevictable folio to lruvec->lists in sort_folio().

Signed-off-by: Zhiguo Jiang <justinjiang@vivo.com>
---
 mm/vmscan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
 mode change 100644 => 100755 mm/vmscan.c
  

Comments

Yu Zhao Sept. 14, 2023, 5:46 p.m. UTC | #1
On Thu, Sep 14, 2023 at 8:08 AM Zhiguo Jiang <justinjiang@vivo.com> wrote:
>
> The unevictable folio is not supported to add to lruvec->lists
> in lruvec_add_folio().
>
> So use lruvec_add_folio_tail() instead of lruvec_add_folio()
> to add unevictable folio to lruvec->lists in sort_folio().
>
> Signed-off-by: Zhiguo Jiang <justinjiang@vivo.com>
> ---
>  mm/vmscan.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>  mode change 100644 => 100755 mm/vmscan.c
>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 661615fa709b..a15e45632034
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -4237,7 +4237,7 @@ static bool sort_folio(struct lruvec *lruvec, struct folio *folio, struct scan_c
>                 success = lru_gen_del_folio(lruvec, folio, true);
>                 VM_WARN_ON_ONCE_FOLIO(!success, folio);
>                 folio_set_unevictable(folio);
> -               lruvec_add_folio(lruvec, folio);
> +               lruvec_add_folio_tail(lruvec, folio);
>                 __count_vm_events(UNEVICTABLE_PGCULLED, delta);
>                 return true;
>         }

NAK.

lruvec_add_folio()
{
        ...

        if (lru != LRU_UNEVICTABLE)
                list_add(&folio->lru, &lruvec->lists[lru]);
}

lruvec_add_folio_tail()
{
        ...

        /* This is not expected to be used on LRU_UNEVICTABLE */
        list_add_tail(&folio->lru, &lruvec->lists[lru]);
}

struct page {
        ...
                        union {
                                struct list_head lru;

                                /* Or, for the Unevictable "LRU list" slot */
                                struct {
        ...
}
  
Yu Zhao Sept. 15, 2023, 3:25 a.m. UTC | #2
On Thu, Sep 14, 2023 at 9:19 PM 江志国 <justinjiang@vivo.com> wrote:
>
> Hi Yu Zhao:
>
> How is the unevictable folio managed in kernel?

https://www.kernel.org/doc/Documentation/vm/unevictable-lru.txt

> On Thu, Sep 14, 2023 at 8:08 AM Zhiguo Jiang <justinjiang@vivo.com> wrote:
> >
> > The unevictable folio is not supported to add to lruvec->lists in
> > lruvec_add_folio().
> >
> > So use lruvec_add_folio_tail() instead of lruvec_add_folio() to add
> > unevictable folio to lruvec->lists in sort_folio().
> >
> > Signed-off-by: Zhiguo Jiang <justinjiang@vivo.com>
> > ---
> >  mm/vmscan.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)  mode change 100644 =>
> > 100755 mm/vmscan.c
> >
> > diff --git a/mm/vmscan.c b/mm/vmscan.c index
> > 661615fa709b..a15e45632034
> > --- a/mm/vmscan.c
> > +++ b/mm/vmscan.c
> > @@ -4237,7 +4237,7 @@ static bool sort_folio(struct lruvec *lruvec, struct folio *folio, struct scan_c
> >                 success = lru_gen_del_folio(lruvec, folio, true);
> >                 VM_WARN_ON_ONCE_FOLIO(!success, folio);
> >                 folio_set_unevictable(folio);
> > -               lruvec_add_folio(lruvec, folio);
> > +               lruvec_add_folio_tail(lruvec, folio);
> >                 __count_vm_events(UNEVICTABLE_PGCULLED, delta);
> >                 return true;
> >         }
>
> NAK.
>
> lruvec_add_folio()
> {
>         ...
>
>         if (lru != LRU_UNEVICTABLE)
>                 list_add(&folio->lru, &lruvec->lists[lru]); }
>
> lruvec_add_folio_tail()
> {
>         ...
>
>         /* This is not expected to be used on LRU_UNEVICTABLE */
>         list_add_tail(&folio->lru, &lruvec->lists[lru]); }
>
> struct page {
>         ...
>                         union {
>                                 struct list_head lru;
>
>                                 /* Or, for the Unevictable "LRU list" slot */
>                                 struct {
>         ...
> }
  
Yu Zhao Sept. 15, 2023, 3:34 a.m. UTC | #3
On Thu, Sep 14, 2023 at 9:33 PM 江志国 <justinjiang@vivo.com> wrote:
>
> Hi Yu Zhao:
>
> Thank you for your reply and sharing.

Sorry, wrong link. This is the right one:

https://www.kernel.org/doc/html/latest/mm/unevictable-lru.html#the-unevictable-lru-folio-list

> On Thu, Sep 14, 2023 at 9:19 PM 江志国 <justinjiang@vivo.com> wrote:
> >
> > Hi Yu Zhao:
> >
> > How is the unevictable folio managed in kernel?
>
> https://www.kernel.org/doc/Documentation/vm/unevictable-lru.txt
>
> > On Thu, Sep 14, 2023 at 8:08 AM Zhiguo Jiang <justinjiang@vivo.com> wrote:
> > >
> > > The unevictable folio is not supported to add to lruvec->lists in
> > > lruvec_add_folio().
> > >
> > > So use lruvec_add_folio_tail() instead of lruvec_add_folio() to add
> > > unevictable folio to lruvec->lists in sort_folio().
> > >
> > > Signed-off-by: Zhiguo Jiang <justinjiang@vivo.com>
> > > ---
> > >  mm/vmscan.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)  mode change 100644
> > > =>
> > > 100755 mm/vmscan.c
> > >
> > > diff --git a/mm/vmscan.c b/mm/vmscan.c index
> > > 661615fa709b..a15e45632034
> > > --- a/mm/vmscan.c
> > > +++ b/mm/vmscan.c
> > > @@ -4237,7 +4237,7 @@ static bool sort_folio(struct lruvec *lruvec, struct folio *folio, struct scan_c
> > >                 success = lru_gen_del_folio(lruvec, folio, true);
> > >                 VM_WARN_ON_ONCE_FOLIO(!success, folio);
> > >                 folio_set_unevictable(folio);
> > > -               lruvec_add_folio(lruvec, folio);
> > > +               lruvec_add_folio_tail(lruvec, folio);
> > >                 __count_vm_events(UNEVICTABLE_PGCULLED, delta);
> > >                 return true;
> > >         }
> >
> > NAK.
> >
> > lruvec_add_folio()
> > {
> >         ...
> >
> >         if (lru != LRU_UNEVICTABLE)
> >                 list_add(&folio->lru, &lruvec->lists[lru]); }
> >
> > lruvec_add_folio_tail()
> > {
> >         ...
> >
> >         /* This is not expected to be used on LRU_UNEVICTABLE */
> >         list_add_tail(&folio->lru, &lruvec->lists[lru]); }
> >
> > struct page {
> >         ...
> >                         union {
> >                                 struct list_head lru;
> >
> >                                 /* Or, for the Unevictable "LRU list" slot */
> >                                 struct {
> >         ...
> > }
  

Patch

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 661615fa709b..a15e45632034
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -4237,7 +4237,7 @@  static bool sort_folio(struct lruvec *lruvec, struct folio *folio, struct scan_c
 		success = lru_gen_del_folio(lruvec, folio, true);
 		VM_WARN_ON_ONCE_FOLIO(!success, folio);
 		folio_set_unevictable(folio);
-		lruvec_add_folio(lruvec, folio);
+		lruvec_add_folio_tail(lruvec, folio);
 		__count_vm_events(UNEVICTABLE_PGCULLED, delta);
 		return true;
 	}