2019-11-13 04:31:19

by John Hubbard

Subject: [PATCH v4 03/23] mm/gup: move try_get_compound_head() to top, fix minor issues

An upcoming patch uses try_get_compound_head() more widely,
so move it to the top of gup.c.

Also fix a tiny spelling error and a checkpatch.pl warning.

Signed-off-by: John Hubbard <[email protected]>
---
mm/gup.c | 29 +++++++++++++++--------------
1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/mm/gup.c b/mm/gup.c
index 199da99e8ffc..933524de6249 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -29,6 +29,21 @@ struct follow_page_context {
unsigned int page_mask;
};

+/*
+ * Return the compound head page with ref appropriately incremented,
+ * or NULL if that failed.
+ */
+static inline struct page *try_get_compound_head(struct page *page, int refs)
+{
+ struct page *head = compound_head(page);
+
+ if (WARN_ON_ONCE(page_ref_count(head) < 0))
+ return NULL;
+ if (unlikely(!page_cache_add_speculative(head, refs)))
+ return NULL;
+ return head;
+}
+
/**
* put_user_pages_dirty_lock() - release and optionally dirty gup-pinned pages
* @pages: array of pages to be maybe marked dirty, and definitely released.
@@ -1793,20 +1808,6 @@ static void __maybe_unused undo_dev_pagemap(int *nr, int nr_start,
}
}

-/*
- * Return the compund head page with ref appropriately incremented,
- * or NULL if that failed.
- */
-static inline struct page *try_get_compound_head(struct page *page, int refs)
-{
- struct page *head = compound_head(page);
- if (WARN_ON_ONCE(page_ref_count(head) < 0))
- return NULL;
- if (unlikely(!page_cache_add_speculative(head, refs)))
- return NULL;
- return head;
-}
-
#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
unsigned int flags, struct page **pages, int *nr)
--
2.24.0

2019-11-13 10:53:42

by Jan Kara

Subject: Re: [PATCH v4 03/23] mm/gup: move try_get_compound_head() to top, fix minor issues

On Tue 12-11-19 20:26:50, John Hubbard wrote:
> An upcoming patch uses try_get_compound_head() more widely,
> so move it to the top of gup.c.
>
> Also fix a tiny spelling error and a checkpatch.pl warning.
>
> Signed-off-by: John Hubbard <[email protected]>

Looks good. You can add:

Reviewed-by: Jan Kara <[email protected]>

Honza

> ---
> mm/gup.c | 29 +++++++++++++++--------------
> 1 file changed, 15 insertions(+), 14 deletions(-)
>
> diff --git a/mm/gup.c b/mm/gup.c
> index 199da99e8ffc..933524de6249 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -29,6 +29,21 @@ struct follow_page_context {
> unsigned int page_mask;
> };
>
> +/*
> + * Return the compound head page with ref appropriately incremented,
> + * or NULL if that failed.
> + */
> +static inline struct page *try_get_compound_head(struct page *page, int refs)
> +{
> + struct page *head = compound_head(page);
> +
> + if (WARN_ON_ONCE(page_ref_count(head) < 0))
> + return NULL;
> + if (unlikely(!page_cache_add_speculative(head, refs)))
> + return NULL;
> + return head;
> +}
> +
> /**
> * put_user_pages_dirty_lock() - release and optionally dirty gup-pinned pages
> * @pages: array of pages to be maybe marked dirty, and definitely released.
> @@ -1793,20 +1808,6 @@ static void __maybe_unused undo_dev_pagemap(int *nr, int nr_start,
> }
> }
>
> -/*
> - * Return the compund head page with ref appropriately incremented,
> - * or NULL if that failed.
> - */
> -static inline struct page *try_get_compound_head(struct page *page, int refs)
> -{
> - struct page *head = compound_head(page);
> - if (WARN_ON_ONCE(page_ref_count(head) < 0))
> - return NULL;
> - if (unlikely(!page_cache_add_speculative(head, refs)))
> - return NULL;
> - return head;
> -}
> -
> #ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
> static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
> unsigned int flags, struct page **pages, int *nr)
> --
> 2.24.0
>
--
Jan Kara <[email protected]>
SUSE Labs, CR

2019-11-13 18:39:29

by Ira Weiny

Subject: Re: [PATCH v4 03/23] mm/gup: move try_get_compound_head() to top, fix minor issues

On Tue, Nov 12, 2019 at 08:26:50PM -0800, John Hubbard wrote:
> An upcoming patch uses try_get_compound_head() more widely,
> so move it to the top of gup.c.
>
> Also fix a tiny spelling error and a checkpatch.pl warning.
>
> Signed-off-by: John Hubbard <[email protected]>

Simple enough...

Reviewed-by: Ira Weiny <[email protected]>

> ---
> mm/gup.c | 29 +++++++++++++++--------------
> 1 file changed, 15 insertions(+), 14 deletions(-)
>
> diff --git a/mm/gup.c b/mm/gup.c
> index 199da99e8ffc..933524de6249 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -29,6 +29,21 @@ struct follow_page_context {
> unsigned int page_mask;
> };
>
> +/*
> + * Return the compound head page with ref appropriately incremented,
> + * or NULL if that failed.
> + */
> +static inline struct page *try_get_compound_head(struct page *page, int refs)
> +{
> + struct page *head = compound_head(page);
> +
> + if (WARN_ON_ONCE(page_ref_count(head) < 0))
> + return NULL;
> + if (unlikely(!page_cache_add_speculative(head, refs)))
> + return NULL;
> + return head;
> +}
> +
> /**
> * put_user_pages_dirty_lock() - release and optionally dirty gup-pinned pages
> * @pages: array of pages to be maybe marked dirty, and definitely released.
> @@ -1793,20 +1808,6 @@ static void __maybe_unused undo_dev_pagemap(int *nr, int nr_start,
> }
> }
>
> -/*
> - * Return the compund head page with ref appropriately incremented,
> - * or NULL if that failed.
> - */
> -static inline struct page *try_get_compound_head(struct page *page, int refs)
> -{
> - struct page *head = compound_head(page);
> - if (WARN_ON_ONCE(page_ref_count(head) < 0))
> - return NULL;
> - if (unlikely(!page_cache_add_speculative(head, refs)))
> - return NULL;
> - return head;
> -}
> -
> #ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
> static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
> unsigned int flags, struct page **pages, int *nr)
> --
> 2.24.0
>