Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753847Ab1DTHeZ (ORCPT ); Wed, 20 Apr 2011 03:34:25 -0400 Received: from mail-gy0-f174.google.com ([209.85.160.174]:49027 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752148Ab1DTHeY convert rfc822-to-8bit (ORCPT ); Wed, 20 Apr 2011 03:34:24 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=rLuKa6jW5MXLtuHjGB+Z3CZlBXKBpu+a2aqFR4KPOsEq+Rfd2ctpZX5EVhUcCexQKS 1IUNpri9my6NZDnjG4EI9V6Eo4CUHDs/Cn2Q5iATfmd1H7Stu+vZUbTAKAVw1tmAdPUJ F80GxFpCCT272WgbZRIUS0hJsqNZhXdTQhhAA= MIME-Version: 1.0 In-Reply-To: <20110420161615.462D.A69D9226@jp.fujitsu.com> References: <20110420102314.4604.A69D9226@jp.fujitsu.com> <20110420161615.462D.A69D9226@jp.fujitsu.com> Date: Wed, 20 Apr 2011 10:34:23 +0300 X-Google-Sender-Auth: mc-uokeCFBxGJtCTURz7SkvWshY Message-ID: Subject: Re: [PATCH v3] mm: make expand_downwards symmetrical to expand_upwards From: Pekka Enberg To: KOSAKI Motohiro Cc: Christoph Lameter , James Bottomley , Michal Hocko , Andrew Morton , Hugh Dickins , linux-mm@kvack.org, LKML , linux-parisc@vger.kernel.org, David Rientjes , Ingo Molnar , x86 maintainers Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1664 Lines: 45 Hi! On Wed, Apr 20, 2011 at 4:23 AM, KOSAKI Motohiro >> wrote: >> > I'm worry about this patch. A lot of mm code assume !NUMA systems >> > only have node 0. Not only SLUB. >> >> So is that a valid assumption or not? Christoph seems to think it is >> and James seems to think it's not. Which way should we aim to fix it? >> Would be nice if other people chimed in as we already know what James >> and Christoph think. On Wed, Apr 20, 2011 at 10:15 AM, KOSAKI Motohiro wrote: > I'm sorry. I don't know it really. The fact was gone into historical myst. ;-) > > Now, CONFIG_NUMA has mainly five meanings. > > 1) system may has !0 node id. > 2) compile mm/mempolicy.c (ie enable mempolicy APIs) > 3) Allocator (kmalloc, vmalloc, alloc_page, et al) awake NUMA topology. > 4) enable zone-reclaim feature > 5) scheduler makes per-node load balancing scheduler domain > > Anyway, we have to fix this issue. ?I'm digging which fixing way has least risk. > > > btw, x86 don't have an issue. Probably it's a reason why this issue was neglected > long time. > > arch/x86/Kconfig > ------------------------------------- > config ARCH_DISCONTIGMEM_ENABLE > ? ? ? ?def_bool y > ? ? ? ?depends on NUMA && X86_32 That part makes me think the best option is to make parisc do CONFIG_NUMA as well regardless of the historical intent was. Pekka -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/