2023-01-10 01:09:51

by SeongJae Park

Subject: [PATCH] mm/sl{a,u}b: fix wrong usages of folio_page() for getting head pages

The standard idiom for getting head page of a given folio is
'&folio->page', but some are wrongly using 'folio_page(folio, 0)' for
the purpose. Fix those to use the idiom.

Suggested-by: Matthew Wilcox <[email protected]>
Signed-off-by: SeongJae Park <[email protected]>
---
mm/slab.c | 4 ++--
mm/slub.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/slab.c b/mm/slab.c
index b77be9c6d6b1..a5398676dc60 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1389,7 +1389,7 @@ static void kmem_freepages(struct kmem_cache *cachep, struct slab *slab)

BUG_ON(!folio_test_slab(folio));
__slab_clear_pfmemalloc(slab);
- page_mapcount_reset(folio_page(folio, 0));
+ page_mapcount_reset(&folio->page);
folio->mapping = NULL;
/* Make the mapping reset visible before clearing the flag */
smp_wmb();
@@ -1398,7 +1398,7 @@ static void kmem_freepages(struct kmem_cache *cachep, struct slab *slab)
if (current->reclaim_state)
current->reclaim_state->reclaimed_slab += 1 << order;
unaccount_slab(slab, order, cachep);
- __free_pages(folio_page(folio, 0), order);
+ __free_pages(&folio->page, order);
}

static void kmem_rcu_free(struct rcu_head *head)
diff --git a/mm/slub.c b/mm/slub.c
index 67020074ecb4..d5f20c062004 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2066,7 +2066,7 @@ static void __free_slab(struct kmem_cache *s, struct slab *slab)
if (current->reclaim_state)
current->reclaim_state->reclaimed_slab += pages;
unaccount_slab(slab, order, s);
- __free_pages(folio_page(folio, 0), order);
+ __free_pages(&folio->page, order);
}

static void rcu_free_slab(struct rcu_head *h)
--
2.25.1

2023-01-10 14:42:12

by Vlastimil Babka

Subject: Re: [PATCH] mm/sl{a,u}b: fix wrong usages of folio_page() for getting head pages

On 1/10/23 01:51, SeongJae Park wrote:
> The standard idiom for getting head page of a given folio is
> '&folio->page', but some are wrongly using 'folio_page(folio, 0)' for
> the purpose. Fix those to use the idiom.
>
> Suggested-by: Matthew Wilcox <[email protected]>
> Signed-off-by: SeongJae Park <[email protected]>

Thanks, pushed to slab/for-6.3/cleanups

> ---
> mm/slab.c | 4 ++--
> mm/slub.c | 2 +-
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/mm/slab.c b/mm/slab.c
> index b77be9c6d6b1..a5398676dc60 100644
> --- a/mm/slab.c
> +++ b/mm/slab.c
> @@ -1389,7 +1389,7 @@ static void kmem_freepages(struct kmem_cache *cachep, struct slab *slab)
>
> BUG_ON(!folio_test_slab(folio));
> __slab_clear_pfmemalloc(slab);
> - page_mapcount_reset(folio_page(folio, 0));
> + page_mapcount_reset(&folio->page);
> folio->mapping = NULL;
> /* Make the mapping reset visible before clearing the flag */
> smp_wmb();
> @@ -1398,7 +1398,7 @@ static void kmem_freepages(struct kmem_cache *cachep, struct slab *slab)
> if (current->reclaim_state)
> current->reclaim_state->reclaimed_slab += 1 << order;
> unaccount_slab(slab, order, cachep);
> - __free_pages(folio_page(folio, 0), order);
> + __free_pages(&folio->page, order);
> }
>
> static void kmem_rcu_free(struct rcu_head *head)
> diff --git a/mm/slub.c b/mm/slub.c
> index 67020074ecb4..d5f20c062004 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -2066,7 +2066,7 @@ static void __free_slab(struct kmem_cache *s, struct slab *slab)
> if (current->reclaim_state)
> current->reclaim_state->reclaimed_slab += pages;
> unaccount_slab(slab, order, s);
> - __free_pages(folio_page(folio, 0), order);
> + __free_pages(&folio->page, order);
> }
>
> static void rcu_free_slab(struct rcu_head *h)

2023-01-10 14:59:18

by David Hildenbrand

Subject: Re: [PATCH] mm/sl{a,u}b: fix wrong usages of folio_page() for getting head pages

On 10.01.23 01:51, SeongJae Park wrote:
> The standard idiom for getting head page of a given folio is
> '&folio->page', but some are wrongly using 'folio_page(folio, 0)' for
> the purpose. Fix those to use the idiom.
>
> Suggested-by: Matthew Wilcox <[email protected]>
> Signed-off-by: SeongJae Park <[email protected]>
> ---
> mm/slab.c | 4 ++--
> mm/slub.c | 2 +-
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/mm/slab.c b/mm/slab.c
> index b77be9c6d6b1..a5398676dc60 100644
> --- a/mm/slab.c
> +++ b/mm/slab.c
> @@ -1389,7 +1389,7 @@ static void kmem_freepages(struct kmem_cache *cachep, struct slab *slab)
>
> BUG_ON(!folio_test_slab(folio));
> __slab_clear_pfmemalloc(slab);
> - page_mapcount_reset(folio_page(folio, 0));
> + page_mapcount_reset(&folio->page);
> folio->mapping = NULL;
> /* Make the mapping reset visible before clearing the flag */
> smp_wmb();
> @@ -1398,7 +1398,7 @@ static void kmem_freepages(struct kmem_cache *cachep, struct slab *slab)
> if (current->reclaim_state)
> current->reclaim_state->reclaimed_slab += 1 << order;
> unaccount_slab(slab, order, cachep);
> - __free_pages(folio_page(folio, 0), order);
> + __free_pages(&folio->page, order);
> }
>
> static void kmem_rcu_free(struct rcu_head *head)
> diff --git a/mm/slub.c b/mm/slub.c
> index 67020074ecb4..d5f20c062004 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -2066,7 +2066,7 @@ static void __free_slab(struct kmem_cache *s, struct slab *slab)
> if (current->reclaim_state)
> current->reclaim_state->reclaimed_slab += pages;
> unaccount_slab(slab, order, s);
> - __free_pages(folio_page(folio, 0), order);
> + __free_pages(&folio->page, order);
> }
>
> static void rcu_free_slab(struct rcu_head *h)

Reviewed-by: David Hildenbrand <[email protected]>

--
Thanks,

David / dhildenb

2023-01-11 09:46:17

by Hyeonggon Yoo

Subject: Re: [PATCH] mm/sl{a,u}b: fix wrong usages of folio_page() for getting head pages

On Tue, Jan 10, 2023 at 12:51:24AM +0000, SeongJae Park wrote:
> The standard idiom for getting head page of a given folio is
> '&folio->page', but some are wrongly using 'folio_page(folio, 0)' for
> the purpose. Fix those to use the idiom.
>
> Suggested-by: Matthew Wilcox <[email protected]>
> Signed-off-by: SeongJae Park <[email protected]>
> ---
> mm/slab.c | 4 ++--
> mm/slub.c | 2 +-
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/mm/slab.c b/mm/slab.c
> index b77be9c6d6b1..a5398676dc60 100644
> --- a/mm/slab.c
> +++ b/mm/slab.c
> @@ -1389,7 +1389,7 @@ static void kmem_freepages(struct kmem_cache *cachep, struct slab *slab)
>
> BUG_ON(!folio_test_slab(folio));
> __slab_clear_pfmemalloc(slab);
> - page_mapcount_reset(folio_page(folio, 0));
> + page_mapcount_reset(&folio->page);
> folio->mapping = NULL;
> /* Make the mapping reset visible before clearing the flag */
> smp_wmb();
> @@ -1398,7 +1398,7 @@ static void kmem_freepages(struct kmem_cache *cachep, struct slab *slab)
> if (current->reclaim_state)
> current->reclaim_state->reclaimed_slab += 1 << order;
> unaccount_slab(slab, order, cachep);
> - __free_pages(folio_page(folio, 0), order);
> + __free_pages(&folio->page, order);
> }
>
> static void kmem_rcu_free(struct rcu_head *head)
> diff --git a/mm/slub.c b/mm/slub.c
> index 67020074ecb4..d5f20c062004 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -2066,7 +2066,7 @@ static void __free_slab(struct kmem_cache *s, struct slab *slab)
> if (current->reclaim_state)
> current->reclaim_state->reclaimed_slab += pages;
> unaccount_slab(slab, order, s);
> - __free_pages(folio_page(folio, 0), order);
> + __free_pages(&folio->page, order);
> }
>
> static void rcu_free_slab(struct rcu_head *h)
> --
> 2.25.1
>
>

Acked-by: Hyeonggon Yoo <[email protected]>

Thanks!