From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751459AbaAJIRr (ORCPT ); Fri, 10 Jan 2014 03:17:47 -0500 Received: from cantor2.suse.de ([195.135.220.15]:40008 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750877AbaAJIRq (ORCPT ); Fri, 10 Jan 2014 03:17:46 -0500 Date: Fri, 10 Jan 2014 09:17:44 +0100 From: Michal Hocko To: Andrew Morton Cc: David Rientjes , linux-kernel@vger.kernel.org, Mel Gorman , linux-mm@kvack.org, Dave Hansen Subject: Re: [RFC] mm: show message when updating min_free_kbytes in thp Message-ID: <20140110081744.GC9437@dhcp22.suse.cz> References: <52C5AA61.8060701@intel.com> <20140103033303.GB4106@localhost.localdomain> <52C6FED2.7070700@intel.com> <20140105003501.GC4106@localhost.localdomain> <20140106164604.GC27602@dhcp22.suse.cz> <20140108101611.GD27937@dhcp22.suse.cz> <20140109073259.GK4106@localhost.localdomain> <20140110080504.GA9437@dhcp22.suse.cz> <20140110001344.2af08f11.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140110001344.2af08f11.akpm@linux-foundation.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 10-01-14 00:13:44, Andrew Morton wrote: > On Fri, 10 Jan 2014 09:05:04 +0100 Michal Hocko wrote: > > > > > --- a/mm/huge_memory.c > > > > +++ b/mm/huge_memory.c > > > > @@ -100,6 +100,7 @@ static struct khugepaged_scan khugepaged_scan = { > > > > .mm_head = LIST_HEAD_INIT(khugepaged_scan.mm_head), > > > > }; > > > > > > > > +extern int user_min_free_kbytes; > > > > > > > > > > We don't add extern declarations to .c files. How many other examples of > > > this can you find in mm/? > > > > I have suggested this because general visibility is not needed. > > It's best to use a common declaration which is seen by the definition > site and all references, so everyone agrees on the variable's type. > Otherwise we could have "long foo;" in one file and "extern char foo;" > in another and the compiler won't tell us. I think the linker could > tell us, but it doesn't, afaik. Perhaps there's an option... > > > But if > > you think that it should then include/linux/mm.h sounds like a proper > > place. > > mm/internal.h might suit. min_free_kbytes is in mm.h so I thought having them together would be appropriate. -- Michal Hocko SUSE Labs