From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751435Ab0AVFwY (ORCPT ); Fri, 22 Jan 2010 00:52:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751325Ab0AVFwX (ORCPT ); Fri, 22 Jan 2010 00:52:23 -0500 Received: from mga11.intel.com ([192.55.52.93]:11708 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750846Ab0AVFwX (ORCPT ); Fri, 22 Jan 2010 00:52:23 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.49,322,1262592000"; d="scan'208";a="533534828" Date: Fri, 22 Jan 2010 13:52:17 +0800 From: Wu Fengguang To: Xiaotian Feng 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" Subject: Re: [PATCH 1/3] resources: introduce generic page_is_ram() Message-ID: <20100122055217.GA8358@localhost> References: <20100122032102.137106635@intel.com> <20100122033004.193166010@intel.com> <7b6bb4a51001212115j741e91c4p61f3f1d6e2ec1de4@mail.gmail.com> <20100122053711.GB3761@localhost> <7b6bb4a51001212150h32f62e53ga230b381ce5da126@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <7b6bb4a51001212150h32f62e53ga230b381ce5da126@mail.gmail.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 21, 2010 at 09:50:01PM -0800, Xiaotian Feng wrote: > 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) ? Only several archs defined page_is_ram(), so that would not be feasible for doing a _generic_ page_is_ram(). Thanks, Fengguang