From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f176.google.com (mail-wi0-f176.google.com [209.85.212.176]) by kanga.kvack.org (Postfix) with ESMTP id 610E66B007B for ; Tue, 19 May 2015 00:00:48 -0400 (EDT) Received: by wicmx19 with SMTP id mx19so101317578wic.0 for ; Mon, 18 May 2015 21:00:48 -0700 (PDT) Received: from jenni2.inet.fi (mta-out1.inet.fi. [62.71.2.203]) by mx.google.com with ESMTP id w13si16486188wjq.111.2015.05.18.21.00.46 for ; Mon, 18 May 2015 21:00:47 -0700 (PDT) Date: Tue, 19 May 2015 07:00:32 +0300 From: "Kirill A. Shutemov" Subject: Re: [PATCHv5 20/28] mm: differentiate page_mapped() from page_mapcount() for compound pages Message-ID: <20150519040032.GB5795@node.dhcp.inet.fi> References: <1429823043-157133-1-git-send-email-kirill.shutemov@linux.intel.com> <1429823043-157133-21-git-send-email-kirill.shutemov@linux.intel.com> <555A06B4.2000706@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <555A06B4.2000706@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Vlastimil Babka Cc: "Kirill A. Shutemov" , Andrew Morton , Andrea Arcangeli , Hugh Dickins , Dave Hansen , Mel Gorman , Rik van Riel , Christoph Lameter , Naoya Horiguchi , Steve Capper , "Aneesh Kumar K.V" , Johannes Weiner , Michal Hocko , Jerome Marchand , Sasha Levin , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Mon, May 18, 2015 at 05:35:16PM +0200, Vlastimil Babka wrote: > On 04/23/2015 11:03 PM, Kirill A. Shutemov wrote: > >Let's define page_mapped() to be true for compound pages if any > >sub-pages of the compound page is mapped (with PMD or PTE). > > > >On other hand page_mapcount() return mapcount for this particular small > >page. > > > >This will make cases like page_get_anon_vma() behave correctly once we > >allow huge pages to be mapped with PTE. > > > >Most users outside core-mm should use page_mapcount() instead of > >page_mapped(). > > Does "should" mean that they do that now, or just that you would like them > to? I would like them to. > Should there be a warning before the function then? Ok. > >Signed-off-by: Kirill A. Shutemov > >Tested-by: Sasha Levin > > >--- a/include/linux/mm.h > >+++ b/include/linux/mm.h > >@@ -909,7 +909,16 @@ static inline pgoff_t page_file_index(struct page *page) > > (not shown in the diff) > > * Return true if this page is mapped into pagetables. > > */ > > Expand the comment? Especially if you put compound_head() there. Ok. > > static inline int page_mapped(struct page *page) > > Convert to proper bool while at it? Ok. -- Kirill A. Shutemov -- 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