From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 4D9A36B003D for ; Sun, 15 Feb 2009 19:51:58 -0500 (EST) Received: from m3.gw.fujitsu.co.jp ([10.0.50.73]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n1G0puog013698 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Mon, 16 Feb 2009 09:51:56 +0900 Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id C0AE145DD82 for ; Mon, 16 Feb 2009 09:51:55 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 9F66545DD7E for ; Mon, 16 Feb 2009 09:51:55 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 69D8FE0800F for ; Mon, 16 Feb 2009 09:51:55 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.249.87.105]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 1F06DE08007 for ; Mon, 16 Feb 2009 09:51:55 +0900 (JST) Date: Mon, 16 Feb 2009 09:50:42 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH 1/2] clean up for early_pfn_to_nid Message-Id: <20090216095042.95f4a6d0.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20090213.221226.264144345.davem@davemloft.net> References: <20090212161920.deedea35.kamezawa.hiroyu@jp.fujitsu.com> <20090212162203.db3f07cb.kamezawa.hiroyu@jp.fujitsu.com> <20090213142032.09b4a4da.akpm@linux-foundation.org> <20090213.221226.264144345.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: David Miller Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kosaki.motohiro@jp.fujitsu.com, davem@davemlloft.net, heiko.carstens@de.ibm.com, stable@kernel.org List-ID: On Fri, 13 Feb 2009 22:12:26 -0800 (PST) David Miller wrote: > From: Andrew Morton > Date: Fri, 13 Feb 2009 14:20:32 -0800 > > > I queued these as > > > > mm-clean-up-for-early_pfn_to_nid.patch > > mm-fix-memmap-init-for-handling-memory-hole.patch > > > > and tagged them as needed-in-2.6.28.x. I don't recall whether they are > > needed in earlier -stable releases? > > Every kernel going back to at least 2.6.24 has this bug. It's likely > been around even longer, I didn't bother checking. > Sparc64's one is broken from this commit. 09337f501ebdd224cd69df6d168a5c4fe75d86fa sparc64: Kill CONFIG_SPARC32_COMPAT CONFIG_NODES_SPAN_OTEHR_NODES is set and config allows following kind of NUMA This is requirements from powerpc. low address ---<- max order ->---- high address [Node0][Node1][Node0] So, nid is checked at memmap init. But it included this bug in following case. low address ---<- max order ->---- high address [Node0][Hole][Node0] Hmm..I'm not sure how many kind of machines will see this bug. But there may be some. [kamezawa@bluextal linux-2.6.28]$ grep -R CONFIG_NODES_SPAN arch/* arch/powerpc/configs/celleb_defconfig:CONFIG_NODES_SPAN_OTHER_NODES=y arch/powerpc/configs/pseries_defconfig:CONFIG_NODES_SPAN_OTHER_NODES=y arch/powerpc/configs/cell_defconfig:CONFIG_NODES_SPAN_OTHER_NODES=y arch/sparc64/defconfig:CONFIG_NODES_SPAN_OTHER_NODES=y arch/x86/configs/x86_64_defconfig:CONFIG_NODES_SPAN_OTHER_NODES=y powerpc/sparc64/x86 can see this bug. IMHO, following 2 arch will be safe because.. On x86-64, it seems it doesn't allows above style of memmap. (BUG_ON() will hit) Powerpc is originator of this CONFIG_NODES_SPAN_OTHER_NODES and they did test. Thanks, -Kame -- 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