From: Jan Kara <jack@xxxxxxx> Subject: 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@xxxxxxx Signed-off-by: Jan Kara <jack@xxxxxxx> Acked-by: Mel Gorman <mgorman@xxxxxxx> Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx> Cc: Dave Chinner <david@xxxxxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxx> Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/filemap.c | 72 +++++++++++++++++++++++++++---------------------- 1 file changed, 41 insertions(+), 31 deletions(-) diff -puN mm/filemap.c~mm-factor-out-checks-and-accounting-from-__delete_from_page_cache mm/filemap.c --- a/mm/filemap.c~mm-factor-out-checks-and-accounting-from-__delete_from_page_cache +++ a/mm/filemap.c @@ -181,17 +181,11 @@ static void page_cache_tree_delete(struc 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 pag } /* 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; + + nr = hpage_nr_pages(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)); + __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); } _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
