From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id 476786B0078 for ; Thu, 4 Feb 2010 10:32:37 -0500 (EST) Received: from d28relay01.in.ibm.com (d28relay01.in.ibm.com [9.184.220.58]) by e28smtp06.in.ibm.com (8.14.3/8.13.1) with ESMTP id o14FWVT3027567 for ; Thu, 4 Feb 2010 21:02:31 +0530 Received: from d28av04.in.ibm.com (d28av04.in.ibm.com [9.184.220.66]) by d28relay01.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o14FWV5s2609272 for ; Thu, 4 Feb 2010 21:02:31 +0530 Received: from d28av04.in.ibm.com (loopback [127.0.0.1]) by d28av04.in.ibm.com (8.14.3/8.13.1/NCO v10.0 AVout) with ESMTP id o14FWUJL008668 for ; Fri, 5 Feb 2010 02:32:30 +1100 Date: Thu, 4 Feb 2010 21:02:28 +0530 From: Balbir Singh Subject: Re: [PATCH -mmotm 7/8] memcg: move charges of anonymous swap Message-ID: <20100204153228.GL19641@balbir.in.ibm.com> Reply-To: balbir@linux.vnet.ibm.com References: <20091221143106.6ff3ca15.nishimura@mxp.nes.nec.co.jp> <20091221143816.9794cd17.nishimura@mxp.nes.nec.co.jp> <20100203193127.fe5efa17.akpm@linux-foundation.org> <20100204140942.0ef6d7b1.nishimura@mxp.nes.nec.co.jp> <20100204142736.2a8bec26.kamezawa.hiroyu@jp.fujitsu.com> <20100204071840.GC5574@linux-sh.org> <20100204164441.d012f6fa.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20100204164441.d012f6fa.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: Paul Mundt , Daisuke Nishimura , Andrew Morton , Li Zefan , Paul Menage , linux-mm List-ID: * KAMEZAWA Hiroyuki [2010-02-04 16:44:41]: > On Thu, 4 Feb 2010 16:18:40 +0900 > Paul Mundt wrote: > > > On Thu, Feb 04, 2010 at 02:27:36PM +0900, KAMEZAWA Hiroyuki wrote: > > > > I think memcg should depends on CONIFG_MMU. > > > > > > How do you think ? > > > > > Unless there's a real technical reason to make it depend on CONFIG_MMU, > > that's just papering over the problem, and means that some nommu person > > will have to come back and fix it properly at a later point in time. > > > I have no strong opinion this. It's ok to support as much as possible. > My concern is that there is no !MMU architecture developper around memcg. So, > error report will be delayed. > I don't mind making it depend on CONFIG_MMU, enabling it for !CONFIG_MMU will require some careful thought and work, so I'd rather make that obvious by making it depend on CONFIG_MMU > > > CONFIG_SWAP itself is configurable even with CONFIG_MMU=y, so having > > stubbed out helpers for the CONFIG_SWAP=n case would give the compiler a > > chance to optimize things away in those cases, too. Embedded systems > > especially will often have MMU=y and BLOCK=n, resulting in SWAP being > > unset but swap cache encodings still defined. > > > > How about just changing the is_swap_pte() definition to depend on SWAP > > instead? > > > I think the new feature as "move task charge" itself depends on CONFIG_MMU > because it walks a process's page table. > -- Balbir -- 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