From e2d8cf405525d83e6ca42969be460f94b0339798 Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi Date: Wed, 11 Sep 2013 14:22:03 -0700 Subject: [PATCH] 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 hugepages. Signed-off-by: Naoya Horiguchi Acked-by: Andi Kleen Reviewed-by: Wanpeng Li Acked-by: Hillf 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: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mempolicy.c | 44 +++++++++++++++++++++++++++++++++++++++----- 1 file changed, 39 insertions(+), 5 deletions(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 27022ca890f8..4626be621e74 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -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) +{ +#ifdef CONFIG_HUGETLB_PAGE + int nid; + struct page *page; + + spin_lock(&vma->vm_mm->page_table_lock); + 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); +unlock: + spin_unlock(&vma->vm_mm->page_table_lock); +#else + BUG(); +#endif +} + 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)) + continue; + if (pmd_huge(*pmd) && is_vm_hugetlb_page(vma)) { + check_hugetlb_pmd_range(vma, pmd, nodes, + flags, private); + continue; + } split_huge_page_pmd(vma, addr, pmd); if (pmd_none_or_trans_huge_or_clear_bad(pmd)) continue; @@ -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)) + continue; if (pud_none_or_clear_bad(pud)) continue; 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)), + node); + else + 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, MIGRATE_SYNC, MR_SYSCALL); if (err) - putback_lru_pages(&pagelist); + putback_movable_pages(&pagelist); } return err; -- 2.20.1