From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx108.postini.com [74.125.245.108]) by kanga.kvack.org (Postfix) with SMTP id 9ADC16B005A for ; Thu, 29 Nov 2012 05:39:17 -0500 (EST) Received: from m1.gw.fujitsu.co.jp (unknown [10.0.50.71]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id BB56D3EE0C1 for ; Thu, 29 Nov 2012 19:39:15 +0900 (JST) Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 9EB0145DE60 for ; Thu, 29 Nov 2012 19:39:15 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 71F7E45DE59 for ; Thu, 29 Nov 2012 19:39:15 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 625761DB8057 for ; Thu, 29 Nov 2012 19:39:15 +0900 (JST) Received: from g01jpexchyt30.g01.fujitsu.local (g01jpexchyt30.g01.fujitsu.local [10.128.193.113]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 0C1E01DB8050 for ; Thu, 29 Nov 2012 19:39:15 +0900 (JST) Message-ID: <50B73B22.90500@jp.fujitsu.com> Date: Thu, 29 Nov 2012 19:38:26 +0900 From: Yasuaki Ishimatsu MIME-Version: 1.0 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: owner-linux-mm@kvack.org List-ID: 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" 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, 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