2023-09-14 21:08:55

by zhiguojiang

Subject: [PATCH] mm: mglru: fix add unevictable folio to lruvec->lists

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 <[email protected]>
---
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;
}
--
2.39.0

2023-09-15 00:22:17

by Yu Zhao

Subject: Re: [PATCH] mm: mglru: fix add unevictable folio to lruvec->lists

On Thu, Sep 14, 2023 at 8:08 AM Zhiguo Jiang <[email protected]> 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 <[email protected]>
> ---
> 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 {
...
}

2023-09-15 03:37:29

by Yu Zhao

Subject: Re: [PATCH] mm: mglru: fix add unevictable folio to lruvec->lists

On Thu, Sep 14, 2023 at 9:33 PM 江志国 <[email protected]> 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 <[email protected]> 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 <[email protected]> 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 <[email protected]>
> > > ---
> > > 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 {
> > ...
> > }

2023-09-15 06:32:08

by Yu Zhao

Subject: Re: [PATCH] mm: mglru: fix add unevictable folio to lruvec->lists

On Thu, Sep 14, 2023 at 9:19 PM 江志国 <[email protected]> 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 <[email protected]> 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 <[email protected]>
> > ---
> > 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 {
> ...
> }