diff options
| -rw-r--r-- | mm/ksm.c | 57 |
1 files changed, 10 insertions, 47 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 { @@ -975,33 +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 @@ -1020,9 +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; @@ -1035,6 +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 @@ -1065,6 +1028,7 @@ static int try_to_merge_one_page(struct vm_area_struct *vma, } } +out_unlock: unlock_page(page); out: return err; @@ -1635,8 +1599,7 @@ 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, |