diff options
| -rw-r--r-- | mm/khugepaged.c | 19 |
1 files changed, 7 insertions, 12 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 47b83030fc53..b87bd43993bd 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1286,7 +1286,7 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff) * collapse_shmem - collapse small tmpfs/shmem pages into huge one. * * Basic scheme is simple, details are more complex: - * - allocate and freeze a new huge page; + * - allocate and lock a new huge page; * - scan over radix tree replacing old pages the new one * + swap in pages if necessary; * + fill in gaps; @@ -1294,11 +1294,11 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff) * - if replacing succeed: * + copy data over; * + free old pages; - * + unfreeze huge page; + * + unlock huge page; * - if replacing failed; * + put all pages back and unfreeze them; * + restore gaps in the radix-tree; - * + free huge page; + * + unlock and free huge page; */ static void collapse_shmem(struct mm_struct *mm, struct address_space *mapping, pgoff_t start, @@ -1336,13 +1336,11 @@ static void collapse_shmem(struct mm_struct *mm, __SetPageSwapBacked(new_page); new_page->index = start; new_page->mapping = mapping; - BUG_ON(!page_ref_freeze(new_page, 1)); /* - * At this point the new_page is 'frozen' (page_count() is zero), locked - * and not up-to-date. It's safe to insert it into radix tree, because - * nobody would be able to map it or use it in other way until we - * unfreeze it. + * At this point the new_page is locked and not up-to-date. + * It's safe to insert it into the page cache, because nobody would + * be able to map it or use it in another way until we unlock it. */ index = start; @@ -1520,9 +1518,8 @@ tree_unlocked: index++; } - /* Everything is ready, let's unfreeze the new_page */ SetPageUptodate(new_page); - page_ref_unfreeze(new_page, HPAGE_PMD_NR); + page_ref_add(new_page, HPAGE_PMD_NR - 1); set_page_dirty(new_page); mem_cgroup_commit_charge(new_page, memcg, false, true); lru_cache_add_anon(new_page); @@ -1570,8 +1567,6 @@ tree_unlocked: VM_BUG_ON(nr_none); spin_unlock_irq(&mapping->tree_lock); - /* Unfreeze new_page, caller would take care about freeing it */ - page_ref_unfreeze(new_page, 1); mem_cgroup_cancel_charge(new_page, memcg, true); new_page->mapping = NULL; } |