diff options
| -rw-r--r-- | mm/memory.c | 17 | ||||
| -rw-r--r-- | mm/migrate.c | 13 |
2 files changed, 26 insertions, 4 deletions
diff --git a/mm/memory.c b/mm/memory.c index c1c6d59b2b0..2b73dbde227 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1481,7 +1481,8 @@ struct page *follow_page_mask(struct vm_area_struct *vma, if (pud_none(*pud)) goto no_page_table; if (pud_huge(*pud) && vma->vm_flags & VM_HUGETLB) { - BUG_ON(flags & FOLL_GET); + if (flags & FOLL_GET) + goto out; page = follow_huge_pud(mm, address, pud, flags & FOLL_WRITE); goto out; } @@ -1492,8 +1493,20 @@ struct page *follow_page_mask(struct vm_area_struct *vma, if (pmd_none(*pmd)) goto no_page_table; if (pmd_huge(*pmd) && vma->vm_flags & VM_HUGETLB) { - BUG_ON(flags & FOLL_GET); page = follow_huge_pmd(mm, address, pmd, flags & FOLL_WRITE); + if (flags & FOLL_GET) { + /* + * Refcount on tail pages are not well-defined and + * shouldn't be taken. The caller should handle a NULL + * return when trying to follow tail pages. + */ + if (PageHead(page)) + get_page(page); + else { + page = NULL; + goto out; + } + } goto out; } if ((flags & FOLL_NUMA) && pmd_numa(*pmd)) diff --git a/mm/migrate.c b/mm/migrate.c index 3ec47d3394c..d3137375fa8 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1092,7 +1092,11 @@ static struct page *new_page_node(struct page *p, unsigned long private, *result = &pm->status; - return alloc_pages_exact_node(pm->node, + if (PageHuge(p)) + return alloc_huge_page_node(page_hstate(compound_head(p)), + pm->node); + else + return alloc_pages_exact_node(pm->node, GFP_HIGHUSER_MOVABLE | GFP_THISNODE, 0); } @@ -1152,6 +1156,11 @@ static int do_move_page_to_node_array(struct mm_struct *mm, !migrate_all) goto put_and_set; + if (PageHuge(page)) { + isolate_huge_page(page, &pagelist); + goto put_and_set; + } + err = isolate_lru_page(page); if (!err) { list_add_tail(&page->lru, &pagelist); @@ -1174,7 +1183,7 @@ set_status: err = migrate_pages(&pagelist, new_page_node, (unsigned long)pm, MIGRATE_SYNC, MR_SYSCALL); if (err) - putback_lru_pages(&pagelist); + putback_movable_pages(&pagelist); } up_read(&mm->mmap_sem); |