diff options
Diffstat (limited to 'mm/ksm.c')
| -rw-r--r-- | mm/ksm.c | 89 |
1 files changed, 26 insertions, 63 deletions
@@ -441,20 +441,6 @@ static void break_cow(struct rmap_item *rmap_item) up_read(&mm->mmap_sem); } -static struct page *page_trans_compound_anon(struct page *page) -{ - if (PageTransCompound(page)) { - struct page *head = compound_head(page); - /* - * head may actually be splitted and freed from under - * us but it's ok here. - */ - if (PageAnon(head)) - return head; - } - return NULL; -} - static struct page *get_mergeable_page(struct rmap_item *rmap_item) { struct mm_struct *mm = rmap_item->mm; @@ -470,7 +456,7 @@ static struct page *get_mergeable_page(struct rmap_item *rmap_item) page = follow_page(vma, addr, FOLL_GET); if (IS_ERR_OR_NULL(page)) goto out; - if (PageAnon(page) || page_trans_compound_anon(page)) { + if (PageAnon(page)) { flush_anon_page(vma, page, addr); flush_dcache_page(page); } else { @@ -740,8 +726,7 @@ static int remove_stable_node(struct stable_node *stable_node) static int remove_all_stable_nodes(void) { - struct stable_node *stable_node; - struct list_head *this, *next; + struct stable_node *stable_node, *next; int nid; int err = 0; @@ -756,8 +741,7 @@ static int remove_all_stable_nodes(void) cond_resched(); } } - list_for_each_safe(this, next, &migrate_nodes) { - stable_node = list_entry(this, struct stable_node, list); + list_for_each_entry_safe(stable_node, next, &migrate_nodes, list) { if (remove_stable_node(stable_node)) err = -EBUSY; cond_resched(); @@ -958,13 +942,13 @@ static int replace_page(struct vm_area_struct *vma, struct page *page, } get_page(kpage); - page_add_anon_rmap(kpage, vma, addr); + page_add_anon_rmap(kpage, vma, addr, false); flush_cache_page(vma, addr, pte_pfn(*ptep)); ptep_clear_flush_notify(vma, addr, ptep); set_pte_at_notify(mm, addr, ptep, mk_pte(kpage, vma->vm_page_prot)); - page_remove_rmap(page); + page_remove_rmap(page, false); if (!page_mapped(page)) try_to_free_swap(page); put_page(page); @@ -977,33 +961,6 @@ out: return err; } -static int page_trans_compound_anon_split(struct page *page) -{ - int ret = 0; - struct page *transhuge_head = page_trans_compound_anon(page); - if (transhuge_head) { - /* Get the reference on the head to split it. */ - if (get_page_unless_zero(transhuge_head)) { - /* - * Recheck we got the reference while the head - * was still anonymous. - */ - if (PageAnon(transhuge_head)) - ret = split_huge_page(transhuge_head); - else - /* - * Retry later if split_huge_page run - * from under us. - */ - ret = 1; - put_page(transhuge_head); - } else - /* Retry later if split_huge_page run from under us. */ - ret = 1; - } - return ret; -} - /* * try_to_merge_one_page - take two pages and merge them into one * @vma: the vma that holds the pte pointing to page @@ -1022,9 +979,6 @@ static int try_to_merge_one_page(struct vm_area_struct *vma, if (page == kpage) /* ksm page forked */ return 0; - if (PageTransCompound(page) && page_trans_compound_anon_split(page)) - goto out; - BUG_ON(PageTransCompound(page)); if (!PageAnon(page)) goto out; @@ -1037,6 +991,13 @@ static int try_to_merge_one_page(struct vm_area_struct *vma, */ if (!trylock_page(page)) goto out; + + if (PageTransCompound(page)) { + err = split_huge_page(page); + if (err) + goto out_unlock; + } + /* * If this anonymous page is mapped only here, its pte may need * to be write-protected. If it's mapped elsewhere, all of its @@ -1052,6 +1013,12 @@ static int try_to_merge_one_page(struct vm_area_struct *vma, */ set_page_stable_node(page, NULL); mark_page_accessed(page); + /* + * Page reclaim just frees a clean page with no dirty + * ptes: make sure that the ksm page would be swapped. + */ + if (!PageDirty(page)) + SetPageDirty(page); err = 0; } else if (pages_identical(page, kpage)) err = replace_page(vma, page, kpage, orig_pte); @@ -1067,6 +1034,7 @@ static int try_to_merge_one_page(struct vm_area_struct *vma, } } +out_unlock: unlock_page(page); out: return err; @@ -1583,13 +1551,11 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page) * so prune them once before each full scan. */ if (!ksm_merge_across_nodes) { - struct stable_node *stable_node; - struct list_head *this, *next; + struct stable_node *stable_node, *next; struct page *page; - list_for_each_safe(this, next, &migrate_nodes) { - stable_node = list_entry(this, - struct stable_node, list); + list_for_each_entry_safe(stable_node, next, + &migrate_nodes, list) { page = get_ksm_page(stable_node, false); if (page) put_page(page); @@ -1639,8 +1605,7 @@ next_mm: cond_resched(); continue; } - if (PageAnon(*page) || - page_trans_compound_anon(*page)) { + if (PageAnon(*page)) { flush_anon_page(vma, *page, ksm_scan.address); flush_dcache_page(*page); rmap_item = get_next_rmap_item(slot, @@ -1903,7 +1868,7 @@ struct page *ksm_might_need_to_copy(struct page *page, SetPageDirty(new_page); __SetPageUptodate(new_page); - __set_page_locked(new_page); + __SetPageLocked(new_page); } return new_page; @@ -2012,8 +1977,7 @@ static void wait_while_offlining(void) static void ksm_check_stable_tree(unsigned long start_pfn, unsigned long end_pfn) { - struct stable_node *stable_node; - struct list_head *this, *next; + struct stable_node *stable_node, *next; struct rb_node *node; int nid; @@ -2034,8 +1998,7 @@ static void ksm_check_stable_tree(unsigned long start_pfn, cond_resched(); } } - list_for_each_safe(this, next, &migrate_nodes) { - stable_node = list_entry(this, struct stable_node, list); + list_for_each_entry_safe(stable_node, next, &migrate_nodes, list) { if (stable_node->kpfn >= start_pfn && stable_node->kpfn < end_pfn) remove_node_from_stable_tree(stable_node); |