Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932625Ab2K1Vet (ORCPT ); Wed, 28 Nov 2012 16:34:49 -0500 Received: from mga09.intel.com ([134.134.136.24]:45161 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932565Ab2K1Vep convert rfc822-to-8bit (ORCPT ); Wed, 28 Nov 2012 16:34:45 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,180,1355126400"; d="scan'208";a="226038160" From: "Luck, Tony" To: Jiang Liu , Tang Chen CC: "hpa@zytor.com" , "akpm@linux-foundation.org" , "rob@landley.net" , "isimatu.yasuaki@jp.fujitsu.com" , "laijs@cn.fujitsu.com" , "wency@cn.fujitsu.com" , "linfeng@cn.fujitsu.com" , "yinghai@kernel.org" , "kosaki.motohiro@jp.fujitsu.com" , "minchan.kim@gmail.com" , "mgorman@suse.de" , "rientjes@google.com" , "rusty@rustcorp.com.au" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "linux-doc@vger.kernel.org" , Len Brown , "Wang, Frank" Subject: RE: [PATCH v2 0/5] Add movablecore_map boot option Thread-Topic: [PATCH v2 0/5] Add movablecore_map boot option Thread-Index: AQHNzUWLbzufafl3KEuH3pSKrF3YJJf/w9zA Date: Wed, 28 Nov 2012 21:34:43 +0000 Message-ID: <3908561D78D1C84285E8C5FCA982C28F1C95EDCE@ORSMSX108.amr.corp.intel.com> References: <1353667445-7593-1-git-send-email-tangchen@cn.fujitsu.com> <50B5CFAE.80103@huawei.com> In-Reply-To: <50B5CFAE.80103@huawei.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.22.254.139] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1484 Lines: 32 > 1. use firmware information > According to ACPI spec 5.0, SRAT table has memory affinity structure > and the structure has Hot Pluggable Filed. See "5.2.16.2 Memory > Affinity Structure". If we use the information, we might be able to > specify movable memory by firmware. For example, if Hot Pluggable > Filed is enabled, Linux sets the memory as movable memory. > > 2. use boot option > This is our proposal. New boot option can specify memory range to use > as movable memory. Isn't this just moving the work to the user? To pick good values for the movable areas, they need to know how the memory lines up across node boundaries ... because they need to make sure to allow some non-movable memory allocations on each node so that the kernel can take advantage of node locality. So the user would have to read at least the SRAT table, and perhaps more, to figure out what to provide as arguments. Since this is going to be used on a dynamic system where nodes might be added an removed - the right values for these arguments might change from one boot to the next. So even if the user gets them right on day 1, a month later when a new node has been added, or a broken node removed the values would be stale. -Tony -- 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/