From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-bk0-f43.google.com (mail-bk0-f43.google.com [209.85.214.43]) by kanga.kvack.org (Postfix) with ESMTP id 7BAE36B003C for ; Fri, 14 Mar 2014 09:33:33 -0400 (EDT) Received: by mail-bk0-f43.google.com with SMTP id v15so185463bkz.2 for ; Fri, 14 Mar 2014 06:33:32 -0700 (PDT) Received: from jenni2.inet.fi (mta-out.inet.fi. [195.156.147.13]) by mx.google.com with ESMTP id x9si2460827bkn.255.2014.03.14.06.33.31 for ; Fri, 14 Mar 2014 06:33:31 -0700 (PDT) Date: Fri, 14 Mar 2014 15:33:11 +0200 From: "Kirill A. Shutemov" Subject: Re: [RFC 3/6] mm: support madvise(MADV_FREE) Message-ID: <20140314133311.GA6316@node.dhcp.inet.fi> References: <1394779070-8545-1-git-send-email-minchan@kernel.org> <1394779070-8545-4-git-send-email-minchan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1394779070-8545-4-git-send-email-minchan@kernel.org> Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Andrew Morton , Rik van Riel , Mel Gorman , Hugh Dickins , Dave Hansen , Johannes Weiner , KOSAKI Motohiro , linux-mm@kvack.org, linux-kernel@vger.kernel.org, John Stultz , Jason Evans On Fri, Mar 14, 2014 at 03:37:47PM +0900, Minchan Kim wrote: > diff --git a/include/linux/mm.h b/include/linux/mm.h > index c1b7414c7bef..9b048cabce27 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -933,10 +933,16 @@ void page_address_init(void); > * Please note that, confusingly, "page_mapping" refers to the inode > * address_space which maps the page from disk; whereas "page_mapped" > * refers to user virtual address space into which the page is mapped. > + * > + * PAGE_MAPPING_LZFREE bit is set along with PAGE_MAPPING_ANON bit > + * and then page->mapping points to an anon_vma. This flag is used > + * for lazy freeing the page instead of swap. > */ > #define PAGE_MAPPING_ANON 1 > #define PAGE_MAPPING_KSM 2 > -#define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM) > +#define PAGE_MAPPING_LZFREE 4 > +#define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM | \ > + PAGE_MAPPING_LZFREE) Is it safe to use third bit in pointer everywhere? -- 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