[PATCH 1/2] hugetlb: restrict hugepage_migration_support() to x86_64

[PATCH 1/2] hugetlb: restrict hugepage_migration_support() to x86_64

[Naoya Horiguchi]

Curretly hugepage migration is available for all archs which support pmd-level
hugepage, but testing is done only for x86_64 and there're bugs for other archs.
So to avoid breaking such archs, this patch limits the availability strictly to
x86_64 until developers of other archs get interested in enabling this feature.

Simply disabling hugepage migration on non-x86_64 archs is not enough to fix
the reported problem where sys_move_pages() hits the BUG_ON() in
follow_page(FOLL_GET), so let's fix this by checking if hugepage migration is
supported in vma_migratable().

ChangeLog:
- add VM_HUGETLB check in vma_migratable()
- fix dependency in config ARCH_ENABLE_HUGEPAGE_MIGRATION
- remove comment on hugepage_migration_support()

Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: stable@vger.kernel.org # 3.12+
---
 arch/arm/mm/hugetlbpage.c     |  5 -----
 arch/arm64/mm/hugetlbpage.c   |  5 -----
 arch/ia64/mm/hugetlbpage.c    |  5 -----
 arch/metag/mm/hugetlbpage.c   |  5 -----
 arch/mips/mm/hugetlbpage.c    |  5 -----
 arch/powerpc/mm/hugetlbpage.c | 10 ----------
 arch/s390/mm/hugetlbpage.c    |  5 -----
 arch/sh/mm/hugetlbpage.c      |  5 -----
 arch/sparc/mm/hugetlbpage.c   |  5 -----
 arch/tile/mm/hugetlbpage.c    |  5 -----
 arch/x86/Kconfig              |  4 ++++
 arch/x86/mm/hugetlbpage.c     | 10 ----------
 include/linux/hugetlb.h       | 13 +++++--------
 include/linux/mempolicy.h     |  6 ++++++
 mm/Kconfig                    |  3 +++
 15 files changed, 18 insertions(+), 73 deletions(-)

diff --git v3.15-rc5.orig/arch/arm/mm/hugetlbpage.c v3.15-rc5/arch/arm/mm/hugetlbpage.c
index 54ee6163c181..66781bf34077 100644
--- v3.15-rc5.orig/arch/arm/mm/hugetlbpage.c
+++ v3.15-rc5/arch/arm/mm/hugetlbpage.c
@@ -56,8 +56,3 @@ int pmd_huge(pmd_t pmd)
 {
 	return pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT);
 }
-
-int pmd_huge_support(void)
-{
-	return 1;
-}
diff --git v3.15-rc5.orig/arch/arm64/mm/hugetlbpage.c v3.15-rc5/arch/arm64/mm/hugetlbpage.c
index 5e9aec358306..2fc8258bab2d 100644
--- v3.15-rc5.orig/arch/arm64/mm/hugetlbpage.c
+++ v3.15-rc5/arch/arm64/mm/hugetlbpage.c
@@ -54,11 +54,6 @@ int pud_huge(pud_t pud)
 	return !(pud_val(pud) & PUD_TABLE_BIT);
 }
 
-int pmd_huge_support(void)
-{
-	return 1;
-}
-
 static __init int setup_hugepagesz(char *opt)
 {
 	unsigned long ps = memparse(opt, &opt);
diff --git v3.15-rc5.orig/arch/ia64/mm/hugetlbpage.c v3.15-rc5/arch/ia64/mm/hugetlbpage.c
index 68232db98baa..76069c18ee42 100644
--- v3.15-rc5.orig/arch/ia64/mm/hugetlbpage.c
+++ v3.15-rc5/arch/ia64/mm/hugetlbpage.c
@@ -114,11 +114,6 @@ int pud_huge(pud_t pud)
 	return 0;
 }
 
-int pmd_huge_support(void)
-{
-	return 0;
-}
-
 struct page *
 follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write)
 {
diff --git v3.15-rc5.orig/arch/metag/mm/hugetlbpage.c v3.15-rc5/arch/metag/mm/hugetlbpage.c
index 042431509b56..3c52fa6d0f8e 100644
--- v3.15-rc5.orig/arch/metag/mm/hugetlbpage.c
+++ v3.15-rc5/arch/metag/mm/hugetlbpage.c
@@ -110,11 +110,6 @@ int pud_huge(pud_t pud)
 	return 0;
 }
 
-int pmd_huge_support(void)
-{
-	return 1;
-}
-
 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
 			     pmd_t *pmd, int write)
 {
diff --git v3.15-rc5.orig/arch/mips/mm/hugetlbpage.c v3.15-rc5/arch/mips/mm/hugetlbpage.c
index 77e0ae036e7c..4ec8ee10d371 100644
--- v3.15-rc5.orig/arch/mips/mm/hugetlbpage.c
+++ v3.15-rc5/arch/mips/mm/hugetlbpage.c
@@ -84,11 +84,6 @@ int pud_huge(pud_t pud)
 	return (pud_val(pud) & _PAGE_HUGE) != 0;
 }
 
-int pmd_huge_support(void)
-{
-	return 1;
-}
-
 struct page *
 follow_huge_pmd(struct mm_struct *mm, unsigned long address,
 		pmd_t *pmd, int write)
diff --git v3.15-rc5.orig/arch/powerpc/mm/hugetlbpage.c v3.15-rc5/arch/powerpc/mm/hugetlbpage.c
index eb923654ba80..7e70ae968e5f 100644
--- v3.15-rc5.orig/arch/powerpc/mm/hugetlbpage.c
+++ v3.15-rc5/arch/powerpc/mm/hugetlbpage.c
@@ -86,11 +86,6 @@ int pgd_huge(pgd_t pgd)
 	 */
 	return ((pgd_val(pgd) & 0x3) != 0x0);
 }
-
-int pmd_huge_support(void)
-{
-	return 1;
-}
 #else
 int pmd_huge(pmd_t pmd)
 {
@@ -106,11 +101,6 @@ int pgd_huge(pgd_t pgd)
 {
 	return 0;
 }
-
-int pmd_huge_support(void)
-{
-	return 0;
-}
 #endif
 
 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
diff --git v3.15-rc5.orig/arch/s390/mm/hugetlbpage.c v3.15-rc5/arch/s390/mm/hugetlbpage.c
index 0727a55d87d9..0ff66a7e29bb 100644
--- v3.15-rc5.orig/arch/s390/mm/hugetlbpage.c
+++ v3.15-rc5/arch/s390/mm/hugetlbpage.c
@@ -220,11 +220,6 @@ int pud_huge(pud_t pud)
 	return 0;
 }
 
-int pmd_huge_support(void)
-{
-	return 1;
-}
-
 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
 			     pmd_t *pmdp, int write)
 {
diff --git v3.15-rc5.orig/arch/sh/mm/hugetlbpage.c v3.15-rc5/arch/sh/mm/hugetlbpage.c
index 0d676a41081e..d7762349ea48 100644
--- v3.15-rc5.orig/arch/sh/mm/hugetlbpage.c
+++ v3.15-rc5/arch/sh/mm/hugetlbpage.c
@@ -83,11 +83,6 @@ int pud_huge(pud_t pud)
 	return 0;
 }
 
-int pmd_huge_support(void)
-{
-	return 0;
-}
-
 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
 			     pmd_t *pmd, int write)
 {
diff --git v3.15-rc5.orig/arch/sparc/mm/hugetlbpage.c v3.15-rc5/arch/sparc/mm/hugetlbpage.c
index 9bd9ce80bf77..d329537739c6 100644
--- v3.15-rc5.orig/arch/sparc/mm/hugetlbpage.c
+++ v3.15-rc5/arch/sparc/mm/hugetlbpage.c
@@ -231,11 +231,6 @@ int pud_huge(pud_t pud)
 	return 0;
 }
 
-int pmd_huge_support(void)
-{
-	return 0;
-}
-
 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
 			     pmd_t *pmd, int write)
 {
diff --git v3.15-rc5.orig/arch/tile/mm/hugetlbpage.c v3.15-rc5/arch/tile/mm/hugetlbpage.c
index 0cb3bbaa580c..e514899e1100 100644
--- v3.15-rc5.orig/arch/tile/mm/hugetlbpage.c
+++ v3.15-rc5/arch/tile/mm/hugetlbpage.c
@@ -166,11 +166,6 @@ int pud_huge(pud_t pud)
 	return !!(pud_val(pud) & _PAGE_HUGE_PAGE);
 }
 
-int pmd_huge_support(void)
-{
-	return 1;
-}
-
 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
 			     pmd_t *pmd, int write)
 {
diff --git v3.15-rc5.orig/arch/x86/Kconfig v3.15-rc5/arch/x86/Kconfig
index 25d2c6f7325e..6b8b429c832f 100644
--- v3.15-rc5.orig/arch/x86/Kconfig
+++ v3.15-rc5/arch/x86/Kconfig
@@ -1871,6 +1871,10 @@ config ARCH_ENABLE_SPLIT_PMD_PTLOCK
 	def_bool y
 	depends on X86_64 || X86_PAE
 
+config ARCH_ENABLE_HUGEPAGE_MIGRATION
+	def_bool y
+	depends on X86_64 && HUGETLB_PAGE && MIGRATION
+
 menu "Power management and ACPI options"
 
 config ARCH_HIBERNATION_HEADER
diff --git v3.15-rc5.orig/arch/x86/mm/hugetlbpage.c v3.15-rc5/arch/x86/mm/hugetlbpage.c
index 8c9f647ff9e1..8b977ebf9388 100644
--- v3.15-rc5.orig/arch/x86/mm/hugetlbpage.c
+++ v3.15-rc5/arch/x86/mm/hugetlbpage.c
@@ -58,11 +58,6 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address,
 {
 	return NULL;
 }
-
-int pmd_huge_support(void)
-{
-	return 0;
-}
 #else
 
 struct page *
@@ -80,11 +75,6 @@ int pud_huge(pud_t pud)
 {
 	return !!(pud_val(pud) & _PAGE_PSE);
 }
-
-int pmd_huge_support(void)
-{
-	return 1;
-}
 #endif
 
 #ifdef CONFIG_HUGETLB_PAGE
diff --git v3.15-rc5.orig/include/linux/hugetlb.h v3.15-rc5/include/linux/hugetlb.h
index 63214868c5b2..c9de64cf288d 100644
--- v3.15-rc5.orig/include/linux/hugetlb.h
+++ v3.15-rc5/include/linux/hugetlb.h
@@ -385,15 +385,13 @@ static inline pgoff_t basepage_index(struct page *page)
 
 extern void dissolve_free_huge_pages(unsigned long start_pfn,
 				     unsigned long end_pfn);
-int pmd_huge_support(void);
-/*
- * Currently hugepage migration is enabled only for pmd-based hugepage.
- * This function will be updated when hugepage migration is more widely
- * supported.
- */
 static inline int hugepage_migration_support(struct hstate *h)
 {
-	return pmd_huge_support() && (huge_page_shift(h) == PMD_SHIFT);
+#ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
+	return huge_page_shift(h) == PMD_SHIFT;
+#else
+	return 0;
+#endif
 }
 
 static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
@@ -443,7 +441,6 @@ static inline pgoff_t basepage_index(struct page *page)
 	return page->index;
 }
 #define dissolve_free_huge_pages(s, e)	do {} while (0)
-#define pmd_huge_support()	0
 #define hugepage_migration_support(h)	0
 
 static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
diff --git v3.15-rc5.orig/include/linux/mempolicy.h v3.15-rc5/include/linux/mempolicy.h
index 3c1b968da0ca..f230a978e6ba 100644
--- v3.15-rc5.orig/include/linux/mempolicy.h
+++ v3.15-rc5/include/linux/mempolicy.h
@@ -175,6 +175,12 @@ static inline int vma_migratable(struct vm_area_struct *vma)
 {
 	if (vma->vm_flags & (VM_IO | VM_PFNMAP))
 		return 0;
+
+#ifndef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
+	if (vma->vm_flags & VM_HUGETLB)
+		return 0;
+#endif
+
 	/*
 	 * Migration allocates pages in the highest zone. If we cannot
 	 * do so then migration (at least from node to node) is not
diff --git v3.15-rc5.orig/mm/Kconfig v3.15-rc5/mm/Kconfig
index ebe5880c29d6..1e22701c972b 100644
--- v3.15-rc5.orig/mm/Kconfig
+++ v3.15-rc5/mm/Kconfig
@@ -264,6 +264,9 @@ config MIGRATION
 	  pages as migration can relocate pages to satisfy a huge page
 	  allocation instead of reclaiming.
 
+config ARCH_ENABLE_HUGEPAGE_MIGRATION
+	boolean
+
 config PHYS_ADDR_T_64BIT
 	def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT
 
-- 
1.9.3

[PATCH 2/2] hugetlb: rename hugepage_migration_support() to ..._supported()

[Naoya Horiguchi]

We already have a function named hugepage_supported(), and the similar
name hugepage_migration_support() is a bit unconfortable, so let's rename
it hugepage_migration_supported().

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
---
 include/linux/hugetlb.h | 4 ++--
 mm/hugetlb.c            | 2 +-
 mm/migrate.c            | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git v3.15-rc5.orig/include/linux/hugetlb.h v3.15-rc5/include/linux/hugetlb.h
index c9de64cf288d..9d35e514312b 100644
--- v3.15-rc5.orig/include/linux/hugetlb.h
+++ v3.15-rc5/include/linux/hugetlb.h
@@ -385,7 +385,7 @@ static inline pgoff_t basepage_index(struct page *page)
 
 extern void dissolve_free_huge_pages(unsigned long start_pfn,
 				     unsigned long end_pfn);
-static inline int hugepage_migration_support(struct hstate *h)
+static inline int hugepage_migration_supported(struct hstate *h)
 {
 #ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
 	return huge_page_shift(h) == PMD_SHIFT;
@@ -441,7 +441,7 @@ static inline pgoff_t basepage_index(struct page *page)
 	return page->index;
 }
 #define dissolve_free_huge_pages(s, e)	do {} while (0)
-#define hugepage_migration_support(h)	0
+#define hugepage_migration_supported(h)	0
 
 static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
 					   struct mm_struct *mm, pte_t *pte)
diff --git v3.15-rc5.orig/mm/hugetlb.c v3.15-rc5/mm/hugetlb.c
index ea42b584661a..83d936d12c1d 100644
--- v3.15-rc5.orig/mm/hugetlb.c
+++ v3.15-rc5/mm/hugetlb.c
@@ -545,7 +545,7 @@ static struct page *dequeue_huge_page_node(struct hstate *h, int nid)
 /* Movability of hugepages depends on migration support. */
 static inline gfp_t htlb_alloc_mask(struct hstate *h)
 {
-	if (hugepages_treat_as_movable || hugepage_migration_support(h))
+	if (hugepages_treat_as_movable || hugepage_migration_supported(h))
 		return GFP_HIGHUSER_MOVABLE;
 	else
 		return GFP_HIGHUSER;
diff --git v3.15-rc5.orig/mm/migrate.c v3.15-rc5/mm/migrate.c
index bed48809e5d0..15b589ae6aaf 100644
--- v3.15-rc5.orig/mm/migrate.c
+++ v3.15-rc5/mm/migrate.c
@@ -1031,7 +1031,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
 	 * tables or check whether the hugepage is pmd-based or not before
 	 * kicking migration.
 	 */
-	if (!hugepage_migration_support(page_hstate(hpage))) {
+	if (!hugepage_migration_supported(page_hstate(hpage))) {
 		putback_active_hugepage(hpage);
 		return -ENOSYS;
 	}
-- 
1.9.3

Re: [PATCH 1/2] hugetlb: restrict hugepage_migration_support() to x86_64

[Hugh Dickins]

On Fri, 30 May 2014, Naoya Horiguchi wrote:

> Curretly hugepage migration is available for all archs which support pmd-level
> hugepage, but testing is done only for x86_64 and there're bugs for other archs.
> So to avoid breaking such archs, this patch limits the availability strictly to
> x86_64 until developers of other archs get interested in enabling this feature.
> 
> Simply disabling hugepage migration on non-x86_64 archs is not enough to fix
> the reported problem where sys_move_pages() hits the BUG_ON() in
> follow_page(FOLL_GET), so let's fix this by checking if hugepage migration is
> supported in vma_migratable().
> 
> ChangeLog:
> - add VM_HUGETLB check in vma_migratable()
> - fix dependency in config ARCH_ENABLE_HUGEPAGE_MIGRATION
> - remove comment on hugepage_migration_support()
> 
> Reported-by: Michael Ellerman <mpe@ellerman.id.au>
> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
> Cc: stable@vger.kernel.org # 3.12+

Acked-by: Hugh Dickins <hughd@google.com>

> ---
>  arch/arm/mm/hugetlbpage.c     |  5 -----
>  arch/arm64/mm/hugetlbpage.c   |  5 -----
>  arch/ia64/mm/hugetlbpage.c    |  5 -----
>  arch/metag/mm/hugetlbpage.c   |  5 -----
>  arch/mips/mm/hugetlbpage.c    |  5 -----
>  arch/powerpc/mm/hugetlbpage.c | 10 ----------
>  arch/s390/mm/hugetlbpage.c    |  5 -----
>  arch/sh/mm/hugetlbpage.c      |  5 -----
>  arch/sparc/mm/hugetlbpage.c   |  5 -----
>  arch/tile/mm/hugetlbpage.c    |  5 -----
>  arch/x86/Kconfig              |  4 ++++
>  arch/x86/mm/hugetlbpage.c     | 10 ----------
>  include/linux/hugetlb.h       | 13 +++++--------
>  include/linux/mempolicy.h     |  6 ++++++
>  mm/Kconfig                    |  3 +++
>  15 files changed, 18 insertions(+), 73 deletions(-)
> 
> diff --git v3.15-rc5.orig/arch/arm/mm/hugetlbpage.c v3.15-rc5/arch/arm/mm/hugetlbpage.c
> index 54ee6163c181..66781bf34077 100644
> --- v3.15-rc5.orig/arch/arm/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/arm/mm/hugetlbpage.c
> @@ -56,8 +56,3 @@ int pmd_huge(pmd_t pmd)
>  {
>  	return pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT);
>  }
> -
> -int pmd_huge_support(void)
> -{
> -	return 1;
> -}
> diff --git v3.15-rc5.orig/arch/arm64/mm/hugetlbpage.c v3.15-rc5/arch/arm64/mm/hugetlbpage.c
> index 5e9aec358306..2fc8258bab2d 100644
> --- v3.15-rc5.orig/arch/arm64/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/arm64/mm/hugetlbpage.c
> @@ -54,11 +54,6 @@ int pud_huge(pud_t pud)
>  	return !(pud_val(pud) & PUD_TABLE_BIT);
>  }
>  
> -int pmd_huge_support(void)
> -{
> -	return 1;
> -}
> -
>  static __init int setup_hugepagesz(char *opt)
>  {
>  	unsigned long ps = memparse(opt, &opt);
> diff --git v3.15-rc5.orig/arch/ia64/mm/hugetlbpage.c v3.15-rc5/arch/ia64/mm/hugetlbpage.c
> index 68232db98baa..76069c18ee42 100644
> --- v3.15-rc5.orig/arch/ia64/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/ia64/mm/hugetlbpage.c
> @@ -114,11 +114,6 @@ int pud_huge(pud_t pud)
>  	return 0;
>  }
>  
> -int pmd_huge_support(void)
> -{
> -	return 0;
> -}
> -
>  struct page *
>  follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write)
>  {
> diff --git v3.15-rc5.orig/arch/metag/mm/hugetlbpage.c v3.15-rc5/arch/metag/mm/hugetlbpage.c
> index 042431509b56..3c52fa6d0f8e 100644
> --- v3.15-rc5.orig/arch/metag/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/metag/mm/hugetlbpage.c
> @@ -110,11 +110,6 @@ int pud_huge(pud_t pud)
>  	return 0;
>  }
>  
> -int pmd_huge_support(void)
> -{
> -	return 1;
> -}
> -
>  struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
>  			     pmd_t *pmd, int write)
>  {
> diff --git v3.15-rc5.orig/arch/mips/mm/hugetlbpage.c v3.15-rc5/arch/mips/mm/hugetlbpage.c
> index 77e0ae036e7c..4ec8ee10d371 100644
> --- v3.15-rc5.orig/arch/mips/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/mips/mm/hugetlbpage.c
> @@ -84,11 +84,6 @@ int pud_huge(pud_t pud)
>  	return (pud_val(pud) & _PAGE_HUGE) != 0;
>  }
>  
> -int pmd_huge_support(void)
> -{
> -	return 1;
> -}
> -
>  struct page *
>  follow_huge_pmd(struct mm_struct *mm, unsigned long address,
>  		pmd_t *pmd, int write)
> diff --git v3.15-rc5.orig/arch/powerpc/mm/hugetlbpage.c v3.15-rc5/arch/powerpc/mm/hugetlbpage.c
> index eb923654ba80..7e70ae968e5f 100644
> --- v3.15-rc5.orig/arch/powerpc/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/powerpc/mm/hugetlbpage.c
> @@ -86,11 +86,6 @@ int pgd_huge(pgd_t pgd)
>  	 */
>  	return ((pgd_val(pgd) & 0x3) != 0x0);
>  }
> -
> -int pmd_huge_support(void)
> -{
> -	return 1;
> -}
>  #else
>  int pmd_huge(pmd_t pmd)
>  {
> @@ -106,11 +101,6 @@ int pgd_huge(pgd_t pgd)
>  {
>  	return 0;
>  }
> -
> -int pmd_huge_support(void)
> -{
> -	return 0;
> -}
>  #endif
>  
>  pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
> diff --git v3.15-rc5.orig/arch/s390/mm/hugetlbpage.c v3.15-rc5/arch/s390/mm/hugetlbpage.c
> index 0727a55d87d9..0ff66a7e29bb 100644
> --- v3.15-rc5.orig/arch/s390/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/s390/mm/hugetlbpage.c
> @@ -220,11 +220,6 @@ int pud_huge(pud_t pud)
>  	return 0;
>  }
>  
> -int pmd_huge_support(void)
> -{
> -	return 1;
> -}
> -
>  struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
>  			     pmd_t *pmdp, int write)
>  {
> diff --git v3.15-rc5.orig/arch/sh/mm/hugetlbpage.c v3.15-rc5/arch/sh/mm/hugetlbpage.c
> index 0d676a41081e..d7762349ea48 100644
> --- v3.15-rc5.orig/arch/sh/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/sh/mm/hugetlbpage.c
> @@ -83,11 +83,6 @@ int pud_huge(pud_t pud)
>  	return 0;
>  }
>  
> -int pmd_huge_support(void)
> -{
> -	return 0;
> -}
> -
>  struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
>  			     pmd_t *pmd, int write)
>  {
> diff --git v3.15-rc5.orig/arch/sparc/mm/hugetlbpage.c v3.15-rc5/arch/sparc/mm/hugetlbpage.c
> index 9bd9ce80bf77..d329537739c6 100644
> --- v3.15-rc5.orig/arch/sparc/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/sparc/mm/hugetlbpage.c
> @@ -231,11 +231,6 @@ int pud_huge(pud_t pud)
>  	return 0;
>  }
>  
> -int pmd_huge_support(void)
> -{
> -	return 0;
> -}
> -
>  struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
>  			     pmd_t *pmd, int write)
>  {
> diff --git v3.15-rc5.orig/arch/tile/mm/hugetlbpage.c v3.15-rc5/arch/tile/mm/hugetlbpage.c
> index 0cb3bbaa580c..e514899e1100 100644
> --- v3.15-rc5.orig/arch/tile/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/tile/mm/hugetlbpage.c
> @@ -166,11 +166,6 @@ int pud_huge(pud_t pud)
>  	return !!(pud_val(pud) & _PAGE_HUGE_PAGE);
>  }
>  
> -int pmd_huge_support(void)
> -{
> -	return 1;
> -}
> -
>  struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
>  			     pmd_t *pmd, int write)
>  {
> diff --git v3.15-rc5.orig/arch/x86/Kconfig v3.15-rc5/arch/x86/Kconfig
> index 25d2c6f7325e..6b8b429c832f 100644
> --- v3.15-rc5.orig/arch/x86/Kconfig
> +++ v3.15-rc5/arch/x86/Kconfig
> @@ -1871,6 +1871,10 @@ config ARCH_ENABLE_SPLIT_PMD_PTLOCK
>  	def_bool y
>  	depends on X86_64 || X86_PAE
>  
> +config ARCH_ENABLE_HUGEPAGE_MIGRATION
> +	def_bool y
> +	depends on X86_64 && HUGETLB_PAGE && MIGRATION
> +
>  menu "Power management and ACPI options"
>  
>  config ARCH_HIBERNATION_HEADER
> diff --git v3.15-rc5.orig/arch/x86/mm/hugetlbpage.c v3.15-rc5/arch/x86/mm/hugetlbpage.c
> index 8c9f647ff9e1..8b977ebf9388 100644
> --- v3.15-rc5.orig/arch/x86/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/x86/mm/hugetlbpage.c
> @@ -58,11 +58,6 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address,
>  {
>  	return NULL;
>  }
> -
> -int pmd_huge_support(void)
> -{
> -	return 0;
> -}
>  #else
>  
>  struct page *
> @@ -80,11 +75,6 @@ int pud_huge(pud_t pud)
>  {
>  	return !!(pud_val(pud) & _PAGE_PSE);
>  }
> -
> -int pmd_huge_support(void)
> -{
> -	return 1;
> -}
>  #endif
>  
>  #ifdef CONFIG_HUGETLB_PAGE
> diff --git v3.15-rc5.orig/include/linux/hugetlb.h v3.15-rc5/include/linux/hugetlb.h
> index 63214868c5b2..c9de64cf288d 100644
> --- v3.15-rc5.orig/include/linux/hugetlb.h
> +++ v3.15-rc5/include/linux/hugetlb.h
> @@ -385,15 +385,13 @@ static inline pgoff_t basepage_index(struct page *page)
>  
>  extern void dissolve_free_huge_pages(unsigned long start_pfn,
>  				     unsigned long end_pfn);
> -int pmd_huge_support(void);
> -/*
> - * Currently hugepage migration is enabled only for pmd-based hugepage.
> - * This function will be updated when hugepage migration is more widely
> - * supported.
> - */
>  static inline int hugepage_migration_support(struct hstate *h)
>  {
> -	return pmd_huge_support() && (huge_page_shift(h) == PMD_SHIFT);
> +#ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
> +	return huge_page_shift(h) == PMD_SHIFT;
> +#else
> +	return 0;
> +#endif
>  }
>  
>  static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
> @@ -443,7 +441,6 @@ static inline pgoff_t basepage_index(struct page *page)
>  	return page->index;
>  }
>  #define dissolve_free_huge_pages(s, e)	do {} while (0)
> -#define pmd_huge_support()	0
>  #define hugepage_migration_support(h)	0
>  
>  static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
> diff --git v3.15-rc5.orig/include/linux/mempolicy.h v3.15-rc5/include/linux/mempolicy.h
> index 3c1b968da0ca..f230a978e6ba 100644
> --- v3.15-rc5.orig/include/linux/mempolicy.h
> +++ v3.15-rc5/include/linux/mempolicy.h
> @@ -175,6 +175,12 @@ static inline int vma_migratable(struct vm_area_struct *vma)
>  {
>  	if (vma->vm_flags & (VM_IO | VM_PFNMAP))
>  		return 0;
> +
> +#ifndef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
> +	if (vma->vm_flags & VM_HUGETLB)
> +		return 0;
> +#endif
> +
>  	/*
>  	 * Migration allocates pages in the highest zone. If we cannot
>  	 * do so then migration (at least from node to node) is not
> diff --git v3.15-rc5.orig/mm/Kconfig v3.15-rc5/mm/Kconfig
> index ebe5880c29d6..1e22701c972b 100644
> --- v3.15-rc5.orig/mm/Kconfig
> +++ v3.15-rc5/mm/Kconfig
> @@ -264,6 +264,9 @@ config MIGRATION
>  	  pages as migration can relocate pages to satisfy a huge page
>  	  allocation instead of reclaiming.
>  
> +config ARCH_ENABLE_HUGEPAGE_MIGRATION
> +	boolean
> +
>  config PHYS_ADDR_T_64BIT
>  	def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT
>  
> -- 
> 1.9.3
> 
> 

Re: [PATCH 2/2] hugetlb: rename hugepage_migration_support() to ..._supported()

[Hugh Dickins]

On Fri, 30 May 2014, Naoya Horiguchi wrote:

> We already have a function named hugepage_supported(), and the similar

hugepages_supported()

> name hugepage_migration_support() is a bit unconfortable, so let's rename
> it hugepage_migration_supported().
> 
> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>

Acked-by: Hugh Dickins <hughd@google.com>

> ---
>  include/linux/hugetlb.h | 4 ++--
>  mm/hugetlb.c            | 2 +-
>  mm/migrate.c            | 2 +-
>  3 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git v3.15-rc5.orig/include/linux/hugetlb.h v3.15-rc5/include/linux/hugetlb.h
> index c9de64cf288d..9d35e514312b 100644
> --- v3.15-rc5.orig/include/linux/hugetlb.h
> +++ v3.15-rc5/include/linux/hugetlb.h
> @@ -385,7 +385,7 @@ static inline pgoff_t basepage_index(struct page *page)
>  
>  extern void dissolve_free_huge_pages(unsigned long start_pfn,
>  				     unsigned long end_pfn);
> -static inline int hugepage_migration_support(struct hstate *h)
> +static inline int hugepage_migration_supported(struct hstate *h)
>  {
>  #ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
>  	return huge_page_shift(h) == PMD_SHIFT;
> @@ -441,7 +441,7 @@ static inline pgoff_t basepage_index(struct page *page)
>  	return page->index;
>  }
>  #define dissolve_free_huge_pages(s, e)	do {} while (0)
> -#define hugepage_migration_support(h)	0
> +#define hugepage_migration_supported(h)	0
>  
>  static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
>  					   struct mm_struct *mm, pte_t *pte)
> diff --git v3.15-rc5.orig/mm/hugetlb.c v3.15-rc5/mm/hugetlb.c
> index ea42b584661a..83d936d12c1d 100644
> --- v3.15-rc5.orig/mm/hugetlb.c
> +++ v3.15-rc5/mm/hugetlb.c
> @@ -545,7 +545,7 @@ static struct page *dequeue_huge_page_node(struct hstate *h, int nid)
>  /* Movability of hugepages depends on migration support. */
>  static inline gfp_t htlb_alloc_mask(struct hstate *h)
>  {
> -	if (hugepages_treat_as_movable || hugepage_migration_support(h))
> +	if (hugepages_treat_as_movable || hugepage_migration_supported(h))
>  		return GFP_HIGHUSER_MOVABLE;
>  	else
>  		return GFP_HIGHUSER;
> diff --git v3.15-rc5.orig/mm/migrate.c v3.15-rc5/mm/migrate.c
> index bed48809e5d0..15b589ae6aaf 100644
> --- v3.15-rc5.orig/mm/migrate.c
> +++ v3.15-rc5/mm/migrate.c
> @@ -1031,7 +1031,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
>  	 * tables or check whether the hugepage is pmd-based or not before
>  	 * kicking migration.
>  	 */
> -	if (!hugepage_migration_support(page_hstate(hpage))) {
> +	if (!hugepage_migration_supported(page_hstate(hpage))) {
>  		putback_active_hugepage(hpage);
>  		return -ENOSYS;
>  	}
> -- 
> 1.9.3