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-rw-r--r--arch/arm/mm/hugetlbpage.c5
-rw-r--r--arch/arm64/mm/hugetlbpage.c5
-rw-r--r--arch/ia64/mm/hugetlbpage.c5
-rw-r--r--arch/metag/mm/hugetlbpage.c5
-rw-r--r--arch/mips/mm/hugetlbpage.c5
-rw-r--r--arch/powerpc/mm/hugetlbpage.c10
-rw-r--r--arch/s390/mm/hugetlbpage.c5
-rw-r--r--arch/sh/mm/hugetlbpage.c5
-rw-r--r--arch/sparc/mm/hugetlbpage.c5
-rw-r--r--arch/tile/mm/hugetlbpage.c5
-rw-r--r--arch/x86/mm/hugetlbpage.c8
-rw-r--r--include/linux/hugetlb.h12
-rw-r--r--mm/migrate.c10
13 files changed, 85 insertions, 0 deletions
diff --git a/arch/arm/mm/hugetlbpage.c b/arch/arm/mm/hugetlbpage.c
index 66781bf3..54ee616 100644
--- a/arch/arm/mm/hugetlbpage.c
+++ b/arch/arm/mm/hugetlbpage.c
@@ -56,3 +56,8 @@ 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 a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index 2fc8258..5e9aec3 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -54,6 +54,11 @@ 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 a/arch/ia64/mm/hugetlbpage.c b/arch/ia64/mm/hugetlbpage.c
index 76069c1..68232db 100644
--- a/arch/ia64/mm/hugetlbpage.c
+++ b/arch/ia64/mm/hugetlbpage.c
@@ -114,6 +114,11 @@ 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 a/arch/metag/mm/hugetlbpage.c b/arch/metag/mm/hugetlbpage.c
index 3c52fa6..0424315 100644
--- a/arch/metag/mm/hugetlbpage.c
+++ b/arch/metag/mm/hugetlbpage.c
@@ -110,6 +110,11 @@ 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 a/arch/mips/mm/hugetlbpage.c b/arch/mips/mm/hugetlbpage.c
index a7fee0d..01fda44 100644
--- a/arch/mips/mm/hugetlbpage.c
+++ b/arch/mips/mm/hugetlbpage.c
@@ -85,6 +85,11 @@ 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 a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 834ca8e..d67db4b 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -86,6 +86,11 @@ 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)
{
@@ -101,6 +106,11 @@ 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 a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
index 248445f..d261c62 100644
--- a/arch/s390/mm/hugetlbpage.c
+++ b/arch/s390/mm/hugetlbpage.c
@@ -223,6 +223,11 @@ 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 a/arch/sh/mm/hugetlbpage.c b/arch/sh/mm/hugetlbpage.c
index d776234..0d676a4 100644
--- a/arch/sh/mm/hugetlbpage.c
+++ b/arch/sh/mm/hugetlbpage.c
@@ -83,6 +83,11 @@ 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 a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c
index d2b5944..9639964 100644
--- a/arch/sparc/mm/hugetlbpage.c
+++ b/arch/sparc/mm/hugetlbpage.c
@@ -234,6 +234,11 @@ 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 a/arch/tile/mm/hugetlbpage.c b/arch/tile/mm/hugetlbpage.c
index e514899..0cb3bba 100644
--- a/arch/tile/mm/hugetlbpage.c
+++ b/arch/tile/mm/hugetlbpage.c
@@ -166,6 +166,11 @@ 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 a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
index 7e73e8c..9d980d8 100644
--- a/arch/x86/mm/hugetlbpage.c
+++ b/arch/x86/mm/hugetlbpage.c
@@ -59,6 +59,10 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address,
return NULL;
}
+int pmd_huge_support(void)
+{
+ return 0;
+}
#else
struct page *
@@ -77,6 +81,10 @@ int pud_huge(pud_t pud)
return !!(pud_val(pud) & _PAGE_PSE);
}
+int pmd_huge_support(void)
+{
+ return 1;
+}
#endif
/* x86_64 also uses this file */
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 2e02c4e..0393270 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -381,6 +381,16 @@ 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);
+}
#else /* CONFIG_HUGETLB_PAGE */
struct hstate {};
@@ -409,6 +419,8 @@ 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
#endif /* CONFIG_HUGETLB_PAGE */
#endif /* _LINUX_HUGETLB_H */
diff --git a/mm/migrate.c b/mm/migrate.c
index d313737..61f14a1 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -949,6 +949,16 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
struct page *new_hpage = get_new_page(hpage, private, &result);
struct anon_vma *anon_vma = NULL;
+ /*
+ * Movability of hugepages depends on architectures and hugepage size.
+ * This check is necessary because some callers of hugepage migration
+ * like soft offline and memory hotremove don't walk through page
+ * tables or check whether the hugepage is pmd-based or not before
+ * kicking migration.
+ */
+ if (!hugepage_migration_support(page_hstate(hpage)))
+ return -ENOSYS;
+
if (!new_hpage)
return -ENOMEM;
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