Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S970658AbdIZXa3 (ORCPT ); Tue, 26 Sep 2017 19:30:29 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:39174 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964864AbdIZXa2 (ORCPT ); Tue, 26 Sep 2017 19:30:28 -0400 Date: Tue, 26 Sep 2017 16:30:27 -0700 From: Andrew Morton To: changbin.du@intel.com Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] mm: update comments for struct page.mapping Message-Id: <20170926163027.12836f5006745fcf6e59ad24@linux-foundation.org> In-Reply-To: <1506410057-22316-1-git-send-email-changbin.du@intel.com> References: <1506410057-22316-1-git-send-email-changbin.du@intel.com> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 803 Lines: 24 On Tue, 26 Sep 2017 15:14:17 +0800 changbin.du@intel.com wrote: > From: Changbin Du > > The struct page.mapping can NULL or points to one object of type > address_space, anon_vma or KSM private structure. > > ... > > --- a/include/linux/mm_types.h > +++ b/include/linux/mm_types.h > @@ -47,8 +47,8 @@ struct page { > * inode address_space, or NULL. > * If page mapped as anonymous > * memory, low bit is set, and > - * it points to anon_vma object: > - * see PAGE_MAPPING_ANON below. > + * it points to anon_vma object > + * or KSM private structure. > */ > void *s_mem; /* slab first object */ > atomic_t compound_mapcount; /* first tail page */ Why did you remove the (useful) reference to PAGE_MAPPING_ANON?