diff options
| -rw-r--r-- | mm/vmscan.c | 95 |
1 files changed, 52 insertions, 43 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 1638814..6fbf707 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -536,7 +536,9 @@ static inline int is_page_cache_freeable(struct page *page) * that isolated the page, the page cache radix tree and * optional buffer heads at page->private. */ - return page_count(page) - page_has_private(page) == 2; + int radix_pins = PageTransHuge(page) && PageSwapCache(page) ? + HPAGE_PMD_NR : 1; + return page_count(page) - page_has_private(page) == 1 + radix_pins; } static int may_write_to_inode(struct inode *inode, struct scan_control *sc) @@ -666,6 +668,7 @@ static int __remove_mapping(struct address_space *mapping, struct page *page, bool reclaimed) { unsigned long flags; + int refcount; BUG_ON(!PageLocked(page)); BUG_ON(mapping != page_mapping(page)); @@ -696,11 +699,15 @@ static int __remove_mapping(struct address_space *mapping, struct page *page, * Note that if SetPageDirty is always performed via set_page_dirty, * and thus under tree_lock, then this ordering is not required. */ - if (!page_ref_freeze(page, 2)) + if (unlikely(PageTransHuge(page)) && PageSwapCache(page)) + refcount = 1 + HPAGE_PMD_NR; + else + refcount = 2; + if (!page_ref_freeze(page, refcount)) goto cannot_free; /* note: atomic_cmpxchg in page_freeze_refs provides the smp_rmb */ if (unlikely(PageDirty(page))) { - page_ref_unfreeze(page, 2); + page_ref_unfreeze(page, refcount); goto cannot_free; } @@ -1122,58 +1129,56 @@ static unsigned long shrink_page_list(struct list_head *page_list, * Try to allocate it some swap space here. * Lazyfree page could be freed directly */ - if (PageAnon(page) && PageSwapBacked(page) && - !PageSwapCache(page)) { - if (!(sc->gfp_mask & __GFP_IO)) - goto keep_locked; - if (PageTransHuge(page)) { - /* cannot split THP, skip it */ - if (!can_split_huge_page(page, NULL)) - goto activate_locked; - /* - * Split pages without a PMD map right - * away. Chances are some or all of the - * tail pages can be freed without IO. - */ - if (!compound_mapcount(page) && - split_huge_page_to_list(page, page_list)) - goto activate_locked; - } - if (!add_to_swap(page)) { - if (!PageTransHuge(page)) - goto activate_locked; - /* Split THP and swap individual base pages */ - if (split_huge_page_to_list(page, page_list)) - goto activate_locked; - if (!add_to_swap(page)) - goto activate_locked; - } - - /* XXX: We don't support THP writes */ - if (PageTransHuge(page) && - split_huge_page_to_list(page, page_list)) { - delete_from_swap_cache(page); - goto activate_locked; - } + if (PageAnon(page) && PageSwapBacked(page)) { + if (!PageSwapCache(page)) { + if (!(sc->gfp_mask & __GFP_IO)) + goto keep_locked; + if (PageTransHuge(page)) { + /* cannot split THP, skip it */ + if (!can_split_huge_page(page, NULL)) + goto activate_locked; + /* + * Split pages without a PMD map right + * away. Chances are some or all of the + * tail pages can be freed without IO. + */ + if (!compound_mapcount(page) && + split_huge_page_to_list(page, + page_list)) + goto activate_locked; + } + if (!add_to_swap(page)) { + if (!PageTransHuge(page)) + goto activate_locked; + /* Fallback to swap normal pages */ + if (split_huge_page_to_list(page, + page_list)) + goto activate_locked; + if (!add_to_swap(page)) + goto activate_locked; + } - may_enter_fs = 1; + may_enter_fs = 1; - /* Adding to swap updated mapping */ - mapping = page_mapping(page); + /* Adding to swap updated mapping */ + mapping = page_mapping(page); + } } else if (unlikely(PageTransHuge(page))) { /* Split file THP */ if (split_huge_page_to_list(page, page_list)) goto keep_locked; } - VM_BUG_ON_PAGE(PageTransHuge(page), page); - /* * The page is mapped into the page tables of one or more * processes. Try to unmap it here. */ if (page_mapped(page)) { - if (!try_to_unmap(page, ttu_flags | TTU_BATCH_FLUSH)) { + enum ttu_flags flags = ttu_flags | TTU_BATCH_FLUSH; + + if (unlikely(PageTransHuge(page))) + flags |= TTU_SPLIT_HUGE_PMD; + if (!try_to_unmap(page, flags)) { nr_unmap_fail++; goto activate_locked; } @@ -1313,7 +1318,11 @@ free_it: * Is there need to periodically free_page_list? It would * appear not as the counts should be low */ - list_add(&page->lru, &free_pages); + if (unlikely(PageTransHuge(page))) { + mem_cgroup_uncharge(page); + (*get_compound_page_dtor(page))(page); + } else + list_add(&page->lru, &free_pages); continue; activate_locked: |
