From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751394Ab0AVFuI (ORCPT ); Fri, 22 Jan 2010 00:50:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751273Ab0AVFuG (ORCPT ); Fri, 22 Jan 2010 00:50:06 -0500 Received: from mail-pw0-f42.google.com ([209.85.160.42]:40509 "EHLO mail-pw0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751213Ab0AVFuF convert rfc822-to-8bit (ORCPT ); Fri, 22 Jan 2010 00:50:05 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=QEzSEhKeS2UGFGjk1Hvv0GNGSEHl/vXuYamBkE89MTzcH6TWqnrLLKjH2sJNHEjXMO Sghznu57Zb9cXGw02seE3us/1POsUuxjr2PfLMZdWD1YnkpXotpzy7oQvZz5H+/Na+NL 6c3nhraei7N54wxYro5QJp7hUhwLANXJdjslI= MIME-Version: 1.0 In-Reply-To: <20100122053711.GB3761@localhost> References: <20100122032102.137106635@intel.com> <20100122033004.193166010@intel.com> <7b6bb4a51001212115j741e91c4p61f3f1d6e2ec1de4@mail.gmail.com> <20100122053711.GB3761@localhost> Date: Fri, 22 Jan 2010 13:50:01 +0800 Message-ID: <7b6bb4a51001212150h32f62e53ga230b381ce5da126@mail.gmail.com> Subject: Re: [PATCH 1/3] resources: introduce generic page_is_ram() From: Xiaotian Feng To: Wu Fengguang Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Andrew Morton , Chen Liqin , Lennox Wu , Ralf Baechle , =?UTF-8?Q?Am=C3=A9rico_Wang?= , "linux-mips@linux-mips.org" , KAMEZAWA Hiroyuki , Yinghai Lu , "x86@kernel.org" , LKML , Andi Kleen , "Zheng, Shaohui" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 22, 2010 at 1:37 PM, Wu Fengguang wrote: > On Thu, Jan 21, 2010 at 10:15:50PM -0700, Xiaotian Feng wrote: >> On Fri, Jan 22, 2010 at 11:21 AM, Wu Fengguang wrote: >> > It's based on walk_system_ram_range(), for archs that don't have >> > their own page_is_ram(). >> > >> > The static verions in MIPS and SCORE are also made global. >> > >> > CC: Chen Liqin >> > CC: Lennox Wu >> > CC: Ralf Baechle >> > CC: Américo Wang >> > CC: linux-mips@linux-mips.org >> > CC: KAMEZAWA Hiroyuki >> > CC: Yinghai Lu >> > Signed-off-by: Wu Fengguang >> > --- >> >  arch/mips/mm/init.c    |    2 +- >> >  arch/score/mm/init.c   |    2 +- >> >  include/linux/ioport.h |    2 ++ >> >  kernel/resource.c      |   11 +++++++++++ >> >  4 files changed, 15 insertions(+), 2 deletions(-) >> > >> > --- linux-mm.orig/kernel/resource.c     2010-01-22 11:20:34.000000000 +0800 >> > +++ linux-mm/kernel/resource.c  2010-01-22 11:20:35.000000000 +0800 >> > @@ -327,6 +327,17 @@ int walk_system_ram_range(unsigned long >> > >> >  #endif >> > >> > +#define PAGE_IS_RAM    24 >> > +static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg) >> > +{ >> > +       return PAGE_IS_RAM; >> > +} >> > +int __attribute__((weak)) page_is_ram(unsigned long pfn) >> > +{ >> > +       return PAGE_IS_RAM == walk_system_ram_range(pfn, 1, NULL, __is_ram); >> > +} >> > +#undef PAGE_IS_RAM >> > + >> >> I'm not sure, but any build test for powerpc/mips/score? > > Sorry, no build tests yet: > >        /bin/sh: score-linux-gcc: command not found > > I just make the mips/score page_is_ram() non-static and assume that > will make it compile. > >> walk_system_ram_range is defined when CONFIG_ARCH_HAS_WALK_MEMORY is not set. >> Is it safe when CONFIG_ARCH_HAS_WALK_MEMORY is set for some powerpc archs? > > Good question. Grep shows that CONFIG_ARCH_HAS_WALK_MEMORY is only > defined for powerpc, and it has its own page_is_ram() as well as > walk_system_ram_range(). > > walk_system_ram_range() must be defined somewhere because it is > expected to be generic routine: exported and called from both > in-kernel and out-of-tree code. > Yes, powerpc has its own walk_system_ram_range() and page_is_ram() ;-) Would it be better if moving the weak attribute page_is_ram() into #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) ? > Thanks, > Fengguang >