2017-06-09 10:26:00

by Arnd Bergmann

Subject: [PATCH] mm: hugetlb: replace some macros with inline functions

All users of dissolve_free_huge_page() that ignore the result cause a warning
when CONFIG_HUGETLB_PAGE is disabled:

mm/memory-failure.c: In function 'me_huge_page':
include/linux/hugetlb.h:556:36: error: statement with no effect [-Werror=unused-value]
#define dissolve_free_huge_page(p) 0

We can avoid this by using an inline function instead of the macro, and I
decided to do the same change for the related helpers as well.

Fixes: mmotm ("mm: hugetlb: soft-offline: dissolve source hugepage after successful migration")
Signed-off-by: Arnd Bergmann <[email protected]>
---
include/linux/hugetlb.h | 31 ++++++++++++++++++++++++++-----
1 file changed, 26 insertions(+), 5 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index dbb118c566cd..57f700ac127e 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -546,16 +546,37 @@ static inline unsigned int pages_per_huge_page(struct hstate *h)
{
return 1;
}
-#define hstate_index_to_shift(index) 0
-#define hstate_index(h) 0
+
+static inline unsigned hstate_index_to_shift(unsigned index)
+{
+ return 0;
+}
+
+static inline int hstate_index(struct hstate *h)
+{
+ return 0;
+}

static inline pgoff_t basepage_index(struct page *page)
{
return page->index;
}
-#define dissolve_free_huge_page(p) 0
-#define dissolve_free_huge_pages(s, e) 0
-#define hugepage_migration_supported(h) false
+
+static inline int dissolve_free_huge_page(struct page *page)
+{
+ return 0;
+}
+
+static inline int dissolve_free_huge_pages(unsigned long start_pfn,
+ unsigned long end_pfn)
+{
+ return 0;
+}
+
+static inline bool hugepage_migration_supported(struct hstate *h)
+{
+ return false;
+}

static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
struct mm_struct *mm, pte_t *pte)
--
2.9.0

2017-06-11 23:51:38

by Naoya Horiguchi

Subject: Re: [PATCH] mm: hugetlb: replace some macros with inline functions

On Fri, Jun 09, 2017 at 12:25:05PM +0200, Arnd Bergmann wrote:
> All users of dissolve_free_huge_page() that ignore the result cause a warning
> when CONFIG_HUGETLB_PAGE is disabled:
>
> mm/memory-failure.c: In function 'me_huge_page':
> include/linux/hugetlb.h:556:36: error: statement with no effect [-Werror=unused-value]
> #define dissolve_free_huge_page(p) 0
>
> We can avoid this by using an inline function instead of the macro, and I
> decided to do the same change for the related helpers as well.
>
> Fixes: mmotm ("mm: hugetlb: soft-offline: dissolve source hugepage after successful migration")
> Signed-off-by: Arnd Bergmann <[email protected]>

Right, thank you for catching this.

Acked-by: Naoya Horiguchi <[email protected]>

> ---
> include/linux/hugetlb.h | 31 ++++++++++++++++++++++++++-----
> 1 file changed, 26 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index dbb118c566cd..57f700ac127e 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -546,16 +546,37 @@ static inline unsigned int pages_per_huge_page(struct hstate *h)
> {
> return 1;
> }
> -#define hstate_index_to_shift(index) 0
> -#define hstate_index(h) 0
> +
> +static inline unsigned hstate_index_to_shift(unsigned index)
> +{
> + return 0;
> +}
> +
> +static inline int hstate_index(struct hstate *h)
> +{
> + return 0;
> +}
>
> static inline pgoff_t basepage_index(struct page *page)
> {
> return page->index;
> }
> -#define dissolve_free_huge_page(p) 0
> -#define dissolve_free_huge_pages(s, e) 0
> -#define hugepage_migration_supported(h) false
> +
> +static inline int dissolve_free_huge_page(struct page *page)
> +{
> + return 0;
> +}
> +
> +static inline int dissolve_free_huge_pages(unsigned long start_pfn,
> + unsigned long end_pfn)
> +{
> + return 0;
> +}
> +
> +static inline bool hugepage_migration_supported(struct hstate *h)
> +{
> + return false;
> +}
>
> static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
> struct mm_struct *mm, pte_t *pte)
> --
> 2.9.0
>
>