From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f69.google.com (mail-pl0-f69.google.com [209.85.160.69]) by kanga.kvack.org (Postfix) with ESMTP id D3A246B0261 for ; Wed, 20 Dec 2017 10:56:02 -0500 (EST) Received: by mail-pl0-f69.google.com with SMTP id 3so8170292plv.17 for ; Wed, 20 Dec 2017 07:56:02 -0800 (PST) Received: from bombadil.infradead.org (bombadil.infradead.org. [65.50.211.133]) by mx.google.com with ESMTPS id 70si13406605pfr.84.2017.12.20.07.56.01 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 20 Dec 2017 07:56:01 -0800 (PST) From: Matthew Wilcox Subject: [PATCH v2 4/8] mm: Improve comment on page->mapping Date: Wed, 20 Dec 2017 07:55:48 -0800 Message-Id: <20171220155552.15884-5-willy@infradead.org> In-Reply-To: <20171220155552.15884-1-willy@infradead.org> References: <20171220155552.15884-1-willy@infradead.org> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: akpm@linuxfoundation.org, Matthew Wilcox From: Matthew Wilcox The comment on page->mapping is terse, and out of date (it does not mention the possibility of PAGE_MAPPING_MOVABLE). Instead, point the interested reader to page-flags.h where there is a much better comment. Signed-off-by: Matthew Wilcox Acked-by: Kirill A. Shutemov Acked-by: Michal Hocko Acked-by: Christoph Lameter --- include/linux/mm_types.h | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index c2294e6204e8..8c3b8cea22ee 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -50,15 +50,9 @@ struct page { unsigned long flags; /* Atomic flags, some possibly * updated asynchronously */ union { - struct address_space *mapping; /* If low bit clear, points to - * inode address_space, or NULL. - * If page mapped as anonymous - * memory, low bit is set, and - * it points to anon_vma object - * or KSM private structure. See - * PAGE_MAPPING_ANON and - * PAGE_MAPPING_KSM. - */ + /* See page-flags.h for the definition of PAGE_MAPPING_FLAGS */ + struct address_space *mapping; + void *s_mem; /* slab first object */ atomic_t compound_mapcount; /* first tail page */ /* page_deferred_list().next -- second tail page */ -- 2.15.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org