diff options
| -rw-r--r-- | mm/memory.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/mm/memory.c b/mm/memory.c index 78d17fb97af9..8cd80ba56474 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1302,6 +1302,17 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, return ret; } +/* Whether we should zap all COWed (private) pages too */ +static inline bool should_zap_cows(struct zap_details *details) +{ + /* By default, zap all pages */ + if (!details) + return true; + + /* Or, we zap COWed pages only if the caller wants to */ + return !details->check_mapping; +} + static unsigned long zap_pte_range(struct mmu_gather *tlb, struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, unsigned long end, @@ -1390,17 +1401,19 @@ again: continue; } - /* If details->check_mapping, we leave swap entries. */ - if (unlikely(details)) - continue; - entry = pte_to_swp_entry(ptent); - if (!non_swap_entry(entry)) + if (!non_swap_entry(entry)) { + /* Genuine swap entry, hence a private anon page */ + if (!should_zap_cows(details)) + continue; rss[MM_SWAPENTS]--; - else if (is_migration_entry(entry)) { + } else if (is_migration_entry(entry)) { struct page *page; page = migration_entry_to_page(entry); + if (details && details->check_mapping && + details->check_mapping != page_rmapping(page)) + continue; rss[mm_counter(page)]--; } if (unlikely(!free_swap_and_cache(entry))) |