Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753958Ab2K2KjT (ORCPT ); Thu, 29 Nov 2012 05:39:19 -0500 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:40255 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751077Ab2K2KjR (ORCPT ); Thu, 29 Nov 2012 05:39:17 -0500 X-SecurityPolicyCheck: OK by SHieldMailChecker v1.7.4 Message-ID: <50B73B22.90500@jp.fujitsu.com> Date: Thu, 29 Nov 2012 19:38:26 +0900 From: Yasuaki Ishimatsu User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:16.0) Gecko/20121026 Thunderbird/16.0.2 MIME-Version: 1.0 To: "Luck, Tony" CC: Jiang Liu , Tang Chen , "hpa@zytor.com" , "akpm@linux-foundation.org" , "rob@landley.net" , "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 References: <1353667445-7593-1-git-send-email-tangchen@cn.fujitsu.com> <50B5CFAE.80103@huawei.com> <3908561D78D1C84285E8C5FCA982C28F1C95EDCE@ORSMSX108.amr.corp.intel.com> In-Reply-To: <3908561D78D1C84285E8C5FCA982C28F1C95EDCE@ORSMSX108.amr.corp.intel.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2026 Lines: 57 Hi Tony, 2012/11/29 6:34, Luck, Tony wrote: >> 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 Yes. > 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. There is no problem. Linux has already two boot options, kernelcore= and movablecore=. So if we use them, non-movable memory is divided into each node evenly. But there is no way to specify a node used as movable currently. So we proposed the new boot option. > 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. I don't think so. Even if we hot add/remove node, the memory range of each memory device is not changed. So we don't need to change the boot option. Thanks, Yasuaki Ishimatsu > > -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/