From 5ecc4d852c03b82646bf563460091b95f6a8c7c0 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 15 Nov 2017 17:37:29 -0800 Subject: [PATCH] mm: factor out checks and accounting from __delete_from_page_cache() Move checks and accounting updates from __delete_from_page_cache() into a separate function. We will reuse it when batching page cache truncation operations. Link: http://lkml.kernel.org/r/20171010151937.26984-7-jack@suse.cz Signed-off-by: Jan Kara Acked-by: Mel Gorman Reviewed-by: Andi Kleen Cc: Dave Chinner Cc: Dave Hansen Cc: "Kirill A. Shutemov" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/filemap.c | 72 ++++++++++++++++++++++++++++++---------------------- 1 file changed, 41 insertions(+), 31 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index c649624d386c..a11b42189436 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -181,17 +181,11 @@ static void page_cache_tree_delete(struct address_space *mapping, mapping->nrpages -= nr; } -/* - * Delete a page from the page cache and free it. Caller has to make - * sure the page is locked and that nobody else uses it - or that usage - * is safe. The caller must hold the mapping's tree_lock. - */ -void __delete_from_page_cache(struct page *page, void *shadow) +static void unaccount_page_cache_page(struct address_space *mapping, + struct page *page) { - struct address_space *mapping = page->mapping; - int nr = hpage_nr_pages(page); + int nr; - trace_mm_filemap_delete_from_page_cache(page); /* * if we're uptodate, flush out into the cleancache, otherwise * invalidate any existing cleancache entries. We can't leave @@ -228,30 +222,46 @@ void __delete_from_page_cache(struct page *page, void *shadow) } /* hugetlb pages do not participate in page cache accounting. */ - if (!PageHuge(page)) { - __mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, -nr); - if (PageSwapBacked(page)) { - __mod_node_page_state(page_pgdat(page), NR_SHMEM, -nr); - if (PageTransHuge(page)) - __dec_node_page_state(page, NR_SHMEM_THPS); - } else { - VM_BUG_ON_PAGE(PageTransHuge(page), page); - } + if (PageHuge(page)) + return; - /* - * At this point page must be either written or cleaned by - * truncate. Dirty page here signals a bug and loss of - * unwritten data. - * - * This fixes dirty accounting after removing the page entirely - * but leaves PageDirty set: it has no effect for truncated - * page and anyway will be cleared before returning page into - * buddy allocator. - */ - if (WARN_ON_ONCE(PageDirty(page))) - account_page_cleaned(page, mapping, - inode_to_wb(mapping->host)); + nr = hpage_nr_pages(page); + + __mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, -nr); + if (PageSwapBacked(page)) { + __mod_node_page_state(page_pgdat(page), NR_SHMEM, -nr); + if (PageTransHuge(page)) + __dec_node_page_state(page, NR_SHMEM_THPS); + } else { + VM_BUG_ON_PAGE(PageTransHuge(page), page); } + + /* + * At this point page must be either written or cleaned by + * truncate. Dirty page here signals a bug and loss of + * unwritten data. + * + * This fixes dirty accounting after removing the page entirely + * but leaves PageDirty set: it has no effect for truncated + * page and anyway will be cleared before returning page into + * buddy allocator. + */ + if (WARN_ON_ONCE(PageDirty(page))) + account_page_cleaned(page, mapping, inode_to_wb(mapping->host)); +} + +/* + * Delete a page from the page cache and free it. Caller has to make + * sure the page is locked and that nobody else uses it - or that usage + * is safe. The caller must hold the mapping's tree_lock. + */ +void __delete_from_page_cache(struct page *page, void *shadow) +{ + struct address_space *mapping = page->mapping; + + trace_mm_filemap_delete_from_page_cache(page); + + unaccount_page_cache_page(mapping, page); page_cache_tree_delete(mapping, page, shadow); } -- 2.30.2