Commit e2d8cf40 authored by Naoya Horiguchi's avatar Naoya Horiguchi Committed by Linus Torvalds
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migrate: add hugepage migration code to migrate_pages()

Extend check_range() to handle vma with VM_HUGETLB set.  We will be able
to migrate hugepage with migrate_pages(2) after applying the enablement
patch which comes later in this series.

Note that for larger hugepages (covered by pud entries, 1GB for x86_64 for
example), we simply skip it now.

Note that using pmd_huge/pud_huge assumes that hugepages are pointed to by
pmd/pud.  This is not true in some architectures implementing hugepage
with other mechanisms like ia64, but it's OK because pmd_huge/pud_huge
simply return 0 in such arch and page walker simply ignores such

Signed-off-by: default avatarNaoya Horiguchi <>
Acked-by: default avatarAndi Kleen <>
Reviewed-by: default avatarWanpeng Li <>
Acked-by: default avatarHillf Danton <>
Cc: Mel Gorman <>
Cc: Hugh Dickins <>
Cc: KOSAKI Motohiro <>
Cc: Michal Hocko <>
Cc: Rik van Riel <>
Cc: "Aneesh Kumar K.V" <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent b8ec1cee
......@@ -515,6 +515,30 @@ static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
return addr != end;
static void check_hugetlb_pmd_range(struct vm_area_struct *vma, pmd_t *pmd,
const nodemask_t *nodes, unsigned long flags,
void *private)
int nid;
struct page *page;
page = pte_page(huge_ptep_get((pte_t *)pmd));
nid = page_to_nid(page);
if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT))
goto unlock;
/* With MPOL_MF_MOVE, we migrate only unshared hugepage. */
if (flags & (MPOL_MF_MOVE_ALL) ||
(flags & MPOL_MF_MOVE && page_mapcount(page) == 1))
isolate_huge_page(page, private);
static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud,
unsigned long addr, unsigned long end,
const nodemask_t *nodes, unsigned long flags,
......@@ -526,6 +550,13 @@ static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud,
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
if (!pmd_present(*pmd))
if (pmd_huge(*pmd) && is_vm_hugetlb_page(vma)) {
check_hugetlb_pmd_range(vma, pmd, nodes,
flags, private);
split_huge_page_pmd(vma, addr, pmd);
if (pmd_none_or_trans_huge_or_clear_bad(pmd))
......@@ -547,6 +578,8 @@ static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
pud = pud_offset(pgd, addr);
do {
next = pud_addr_end(addr, end);
if (pud_huge(*pud) && is_vm_hugetlb_page(vma))
if (pud_none_or_clear_bad(pud))
if (check_pmd_range(vma, pud, addr, next, nodes,
......@@ -638,9 +671,6 @@ check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
return ERR_PTR(-EFAULT);
if (is_vm_hugetlb_page(vma))
goto next;
if (flags & MPOL_MF_LAZY) {
change_prot_numa(vma, start, endvma);
goto next;
......@@ -993,7 +1023,11 @@ static void migrate_page_add(struct page *page, struct list_head *pagelist,
static struct page *new_node_page(struct page *page, unsigned long node, int **x)
return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0);
if (PageHuge(page))
return alloc_huge_page_node(page_hstate(compound_head(page)),
return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0);
......@@ -1023,7 +1057,7 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest,
err = migrate_pages(&pagelist, new_node_page, dest,
if (err)
return err;
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