diff options
| -rw-r--r-- | include/linux/mm.h | 1 | ||||
| -rw-r--r-- | mm/memory.c | 5 | ||||
| -rw-r--r-- | mm/migrate.c | 7 |
3 files changed, 12 insertions, 1 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 78adec4ba9f4..2ec5138badab 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1490,6 +1490,7 @@ struct page *follow_page(struct vm_area_struct *, unsigned long address, #define FOLL_DUMP 0x08 /* give error on hole if it would be zero */ #define FOLL_FORCE 0x10 /* get_user_pages read/write w/o permission */ #define FOLL_MLOCK 0x40 /* mark page as mlocked */ +#define FOLL_SPLIT 0x80 /* don't return transhuge pages, split them */ typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr, void *data); diff --git a/mm/memory.c b/mm/memory.c index c1a80e00458d..12ee1ea237f5 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1305,6 +1305,10 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, goto out; } if (pmd_trans_huge(*pmd)) { + if (flags & FOLL_SPLIT) { + split_huge_page_pmd(mm, pmd); + goto split_fallthrough; + } spin_lock(&mm->page_table_lock); if (likely(pmd_trans_huge(*pmd))) { if (unlikely(pmd_trans_splitting(*pmd))) { @@ -1320,6 +1324,7 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, spin_unlock(&mm->page_table_lock); /* fall through */ } +split_fallthrough: if (unlikely(pmd_bad(*pmd))) goto no_page_table; diff --git a/mm/migrate.c b/mm/migrate.c index 690d0de993af..1a531b760b3b 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -113,6 +113,8 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma, goto out; pmd = pmd_offset(pud, addr); + if (pmd_trans_huge(*pmd)) + goto out; if (!pmd_present(*pmd)) goto out; @@ -632,6 +634,9 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private, /* page was freed from under us. So we are done. */ goto move_newpage; } + if (unlikely(PageTransHuge(page))) + if (unlikely(split_huge_page(page))) + goto move_newpage; /* prepare cgroup just returns 0 or -ENOMEM */ rc = -EAGAIN; @@ -1063,7 +1068,7 @@ static int do_move_page_to_node_array(struct mm_struct *mm, if (!vma || pp->addr < vma->vm_start || !vma_migratable(vma)) goto set_status; - page = follow_page(vma, pp->addr, FOLL_GET); + page = follow_page(vma, pp->addr, FOLL_GET|FOLL_SPLIT); err = PTR_ERR(page); if (IS_ERR(page)) |